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  • 1985-1989  (4,111)
  • 1988  (4,111)
  • Polymer and Materials Science  (3,199)
  • Organic Chemistry  (765)
  • Genetics  (147)
Material
Years
  • 1985-1989  (4,111)
Year
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 94 (1988), S. 428-430 
    ISSN: 1432-2072
    Keywords: Lithium ; Clonidine ; alpha2-Adrenoceptor ; Locomotor activity ; Genetics ; Mice
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Four strains of mice (C57, BALB, DBA, C3H) were used to determine whether genetic factors influence the effects of lithium on hypoactivity induced by a low dose of the alpha2-adrenoceptor agonist clonidine (0.2 mg/kg). Lithium was administered in the diet for 3–4 weeks at a dosage that produced average serum lithium levels of 0.58–0.66 mmol/l. Locomotor activity was reduced by either clonidine or by lithium given alone. When combined, however, lithium attenuated the activity-suppressant effects of clonidine, and that action was influenced by genetic factors. The findings suggest that genetic differences in alpha2-adrenoceptors play a role in behavioural effects of lithium.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 76 (1988), S. 405-410 
    ISSN: 1432-2242
    Keywords: Zea mays ; Haploid induction ; Gynogenesis ; Genetics ; Inducer line
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The effect of genotype on maternal haploid plant production in maize was studied. The frequency of gynogenetic plants when “Stock 6” was used as pollinator varied according to the female parent genotype. No simple relation was observed between genotypic aptitudes for gynogenetic and androgenetic development, which occured after pollination of “W23” plant carrying the “indeterminate gametophyte” gene. Furthermore, the population NS, a favorably responsive genotype to anther culture, does not exhibit exceptional ability for in vivo gynogenesis. The effect of inbreeding and the influence of maternal haploid origin suggest that specific genes control maternal haploid initiation and development. However, gynogenetic development is not limited to a particular genotype. The frequency of maternal haploids may be increased by using specific pollen parents. Attempts were made to select for a high haploidyinducing trait and the present study reports the successful development of lines that can be utilized as pollen parents to induce haploids for experimental purposes and breeding programmes. When an inbred line “WS14”, derived from the cross W23 x Stock 6, was used as pollen parent, 2%–5% maternal haploids were obtained according to the female parent genotype. A high haploidy-inducing potential is a heritable trait and may be controlled by a limited number of genes. Genetic determination of the haploidy-inducing character was examined in relation to the efficiency of the selecting method and the mechanisms involved in the origin of maternal haploids.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Pediatric nephrology 2 (1988), S. 239-243 
    ISSN: 1432-198X
    Keywords: Cockayne syndrome ; Renal histology ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Two siblings with typical features of the Cockayne syndrome were studied at autopsy. Many glomeruli revealed a paucity of capillary loops and had thickened capillary walls. Some glomeruli with advanced lesions showed collapse of the glomerular tufts or complete hyalinization. Atrophy of tubules and interstitial fibrosis were also observed. There were no significant arteriosclerotic changes in the vessels. Ultrastructural studies demonstrated thickened glomerular basement membranes with bends and folds. These histopathological findings are different to those previously reported with the exception of the 1966 report by Ohno and Hirooka.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1432-1440
    Keywords: Genetics ; Hepatitis-B virus ; Immunogenetics ; Vaccination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The variation in immune responses to standard inoculation of the hepatitis-B virus vaccine suggest that host factors influence response in ways that are not presently understood. We studied 25 low/nonresponding health care workers (anti-HBs titer 〈50 IU/l) after the third inoculation of an experimental hepatitis-B vaccine to determine their immune status (through lymphocyte phenotypes) and HLA type. After application of a fourth inoculation, the seroconverting subjects showed only low anti-HBs levels; three male subjects remained anti-HBs negative. Twelve months after the fourth inoculation only 9 of 25 subjects (36%) maintained anti-HBs titer 〉10 IU/l. Almost all subjects had normal B-cell and CD-4 and CD-8 counts and ratios. Relative to other European populations HLA-A-10 (P〈0.05), B-12 (P〈0.025), CW-5 (P〈0.05), DR-3 (P〈0.025), and DR-5 (P〈0.025) were increased, whereas DR-2 (P〈0.05) was decreased. However, after correction of theP-values for the number of HLA antigens determined, these differences were no longer significant. Furthermore, these HLA types were not the same as those reported in other studies (except for DR-3). We suggest that larger sample sizes or even not yet available immunogenetic markers will be required to prove an “immunogenetic background” in low/nonresponders, if it exists.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Cellular and molecular life sciences 44 (1988), S. 491-495 
    ISSN: 1420-9071
    Keywords: Genetics ; stress ; emotionality ; locus ceruleus ; Maudsley strains
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The Maudsley Reactive and Non-Reactive strains have been developed as a model for the study of individual variations in stress-reactivity, and many differences in biobehavioral systems have been found between them. This review discusses limitations of the ‘emotionality’ construct in accounting for differences between the Maudsley strains and offers an alternative, theoretical approach. Amaral and Sinnamon have proposed that the locus ceruleus (LC) plays a stress-attenuating role in mediating behavioral, physiological and neuroendocrine response to prepotent, emergency-provoking stimuli and, building upon this formulation, it is proposed that the LC has been an important focus for gene action in the Maudsley model. It is suggested that the LC of the Non-Reactive strain is more strongly activated by stressful stimuli than the LC of Reactive rats, and is the basis of many of the behavioral and physiological differences between them. Behavioral and biochemical evidence consistent with this proposition is reviewed. Identification of the LC as a target for gene-action in the Maudsley model has an important advantage. It substitutes variations at a specific anatomic location in the brain for a loosely defined construct like emotionality, and the hypothesis is amenable to empirical tests by a variety of experimental approaches.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    European journal of pediatrics 147 (1988), S. 550-552 
    ISSN: 1432-1076
    Keywords: Pterygium syndrome ; Congenital malformations ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We present two brothers with Multiple Pterygium Syndrome type Escobar. Characteristic findings in this autosomal recessively inherited pterygium syndrome are, in addition to multiple pterygia, short stature, cleft palate, vertebral fusion defects and minor facial anomalies. The adult height in the two male siblings was below the third centile. Secondary sexual development and testicular size were normal, in contrast with the cryptorchidism and pubertal delay documented in most young patients.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1432-0428
    Keywords: Genetics ; Type 2 (non-insulin-dependent) diabetes ; insulin receptor ; linkage analysis ; maturity onset diabetes of the young
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The possibility of linkage between the human insulin receptor gene locus and diabetes was examined in three Type 2 (non-insulin-dependent) diabetic families and one family with maturity onset diabetes of the young. Insulin receptor gene haplotypes were established using BglII, Rsal and Sstl restriction enzyme digests of genomic DNA from all available family members. The digested DNA was subjected to agarose gel electrophoresis, Southern blotted, and hybridised to 32P-labelled human insulin receptor gene cDNA. In the pedigree with maturity onset diabetes of the young, formal linkage analysis allowed exclusion of close linkage between the insulin receptor locus and diabetes (logarithm of the odds for linkage versus non-linkage was −5.35 at recombination fraction of 0.01). This confirms the absence of linkage between insulin receptor and diabetes which has been reported in two similar pedigrees. In the three Type 2 diabetic families there were a minimum of 4 recombinants between the insulin receptor locus and diabetes, which makes a direct role for insulin receptor defects unlikely. The importance of using realistic estimates of penetrance when performing linkage analysis in a disease with a late age of onset is emphasised. In contrast to the one previous linkage analysis study of the insulin receptor gene, no specific association of diabetes with the rare Sstl Sl(-) allele was observed in either the maturity onset diabetes of the young or the Type 2 diabetic families.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Diabetologia 31 (1988), S. 407-414 
    ISSN: 1432-0428
    Keywords: Genetics ; Type 2 (non-insulin-dependent) diabetes ; linkage analysis ; restriction fragment length polymorphism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In the last five years, genetic markers for a large number of diseases have been localised using linkage analysis of DNA polymorphisms in affected families. The site of the genetic defect or defects leading to Type 2 (non-insulin-dependent) diabetes mellitus, a common illness with a major genetic component, remains unknown. This is due, at least in part, to the lack of large well-defined Type 2 diabetic pedigrees suitable for linkage analysis. There are several features of the disease which make large pedigrees difficult to find. The late age of onset of most probands means that informative older generations are often dead, while there is difficulty in detecting disease in younger generations. The diagnostic criteria for diabetes are, as yet, dependent on an arbitrary cut-off along a continuum of plasma glucose. The high prevalence of the disease may also produce problems as, in any given family, diabetogenic genes may be contributed by more than one parent. Varieties of the disease with a well-defined inheritance, such as maturity onset diabetes of youth, are more suitable for linkage analysis but might be due to defects at a different gene locus. Despite these difficulties, once large well-defined pedigrees have been found, linkage analysis using both candidate genes and random highly polymorphic markers is the strategy most likely to find genetic markers for the disease.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1432-2242
    Keywords: Ornithine decarboxylase ; Chicken ; Muscle ; Genetics ; Growth differences
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Little is known about the biochemical correlates of selection for growth in farm or laboratory animals, or the identity of the gene products affected or produced by ‘trait-genes’. Modern broiler chickens have about 8-fold greater breast muscle mass than layer chickens at 7 weeks of age and over 2-fold greater breast muscle mass than their 1972 counterparts. This increase in muscle mass is associated with over 20-fold higher levels of ornithine decarboxylase (ODC) in broiler chickens at 1 week of age as compared with layer strain chickens; there is a comparable increase in a relaxed-selection strain of broilers. The increase in ODC levels is larger than the differences in muscle or body weight between broilers and layers at 7 weeks of age, occurs at an age when there is no difference in weights between the strains and precedes the major growth spurt. Increases in ODC levels and hence polyamine synthesis have been associated with, and usually precede, rapid growth and cell proliferation in a wide range of cell types and organisms in response to many different stimuli. Therefore, the correlation of ODC levels with genetic differences in muscle growth make it worth investigating the control of ODC gene expression in these strains.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical and applied genetics 75 (1988), S. 889-901 
    ISSN: 1432-2242
    Keywords: Soybean ; Restriction fragment length polymorphism ; Genetics ; Allele ; Variation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Restriction Fragment Length Polymorphisms (RFLP) have been identified between widely distant cultivars (‘Minsoy’ and ‘Noir 1 ’) of soybean Glycine max (L.) Merrill. Using as probes randomly chosen clones of DNA, one in five probes revealed a polymorphism. More than half of these polymorphisms appear to result from rearrangements of the genomic DNA. Twenty seven markers were analyzed for linkage in F2 plants. Eleven of these markers were contained in four linkage groups. Five cultivars were compared in a search for new alleles. When RFLP markers corresponding to low copy DNA were used to analyze three other cultivars — ‘Sooty’, ‘Forrest’ and ‘Mandarin (Ottawa)’ — few new alleles were found. Using these probes, five different markers could be used to differentiate the five cultivars. Complex probes, which correspond to repeated DNA, revealed different polymorphisms in different cultivars and a single such probe could be used to distinguish the five cultivars from each other.
    Type of Medium: Electronic Resource
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  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Psychopharmacology 95 (1988), S. 237-244 
    ISSN: 1432-2072
    Keywords: Morphine ; Etonitazene ; Genetics ; Mice ; Taste ; Saccharine ; Gender
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract C57BL/6J and DBA/2J mouse strains have been characterized as morphine preferrers and avoiders, respectively (Horowitz et al. 1977). Previously, sweetened morphine solutions were presented with a water alternative, primarily with male subjects. Because sweetness may affect the endogenous opioid system and rodents have shown strain and sex differences in taste preferences, this study looked for strain- and gender-related taste preferences that might have affected opiate consumption. Preference for sweetened and unsweetened morphine and etonitazene was compared across gender and strain. In all choice tests, the control was a similar tasting quinine sulphate solution. Under these conditions, C57BL/6J mice continued to show strong preference for morphine. However, DBA/2J mice drank approximately equal amounts of morphine and quinine solutions, rather than avoiding morphine as when water was the alternative. Both strains appeared surprisingly indifferent to the synthetic opioid etonitazene, compared because it is potent at concentrations having barely perceptible bitterness. This raises the possibility of unexpected differences in post-ingestional effects between morphine and etonitazene. Contrary to reports of gender differences in sweet preference in rats, none were found in either strain of mouse. Neither were there any significant sex differences in opiate preference in either strain. C57 mice preferred sweetness more than did DBA mice.
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  • 12
    ISSN: 1432-2072
    Keywords: Selective breeding ; Mouse ; Ethanol-stimulated activity ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Low doses of ethanol (EtOH) stimulate activity in an open field in many strains of laboratory mice. We are selectively breeding two lines of mice to exhibit a large (FAST) response on this test, and two other lines to exhibit a small (SLOW) response (Crabbe et al. 1987). The lines initially diverged in response to EtOH, but despite continued selection pressure, the difference between each pair of FAST and SLOW lines has not increased over generations as much as expected. Our practice has been to test animals on the 1st day after saline injection, and repeat the test after EtOH injection 24 h later. Lister (1987) recently demonstrated that the order in which an animal was exposed to EtOH and saline influenced the magnitude of the response to EtOH, with animals tested initially after EtOH having greater stimulation. Middaugh et al. (1987) recently demonstrated that the magnitude of EtOH stimulation was greater under conditions of relatively bright light than under dim light. Using non-selected Swiss mice, the current experiments essentially confirmed Lister's findings. Using FAST and SLOW mice, the predictions of both groups were tested. Both hypotheses were confirmed. Additionally, these experiments demonstrated that the magnitude of the difference between FAST and SLOW mice was greater under bright light than under dim light. The line difference was also greater when tested in the EtOH-Saline order. In experiments with Swiss mice, the possible role of peritoneal irritation in the EtOH effect was eliminated, and the optimal dose and time for demonstrating the effect was determined. These experiments confirm the importance of lighting condition, order of testing, dose, and route of administration in eliciting EtOH-stimulated open field activity in mice. They demonstrate a genotype-environment interaction, since the magnitude of difference between genetically selected lines varied as a function of the testing parameters chosen. Finally, they indicate that the differences between FAST and SLOW lines in sensitivity to EtOH generalizes to several environmental conditions. We interpret this to mean that the various EtOH-induced activation traits represented by these different environmental and testing conditions are genetically correlated.
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  • 13
    Electronic Resource
    Electronic Resource
    Springer
    Journal of neurology 235 (1988), S. 366-367 
    ISSN: 1432-1459
    Keywords: Gilles de la Tourette's syndrome ; Twin study ; Computed tomography ; Clinical neurophysiology ; Genetics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A 19-year-old male twin pair were concordant for suffering from Gilles de la Tourette's syndrome in different forms and severity. CT revealed ventricular asymmetries of varying degree within the normal range and there were no neurophysiological abnormalities. The interrelationship of genetic and environmental factors in phenotyping the syndrome is discussed.
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  • 14
    Electronic Resource
    Electronic Resource
    Springer
    Journal of neurology 235 (1988), S. 422-424 
    ISSN: 1432-1459
    Keywords: Epidemiology ; Genetics ; Hereditary motor neuropathy ; Spinal muscular atrophy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A 4-year-search for spinal muscular atrophies (hereditary motor neuropathies, HMN) in Benghazi, Libya, yielded a total of 24 patients, among whom 18 were index cases. This group comprised 6 acute infantile, 12 chronic childhood, and 3 each with adult-onset proximal, and distal forms of the disorder. Distal HMN constituted 12.5% of the total cases. The crude average annual incidence of acute infantile HMN was 0.3/100,000 total population and 1/12,500 births in Benghazi. The crude prevalence rates of chronic childhood, adult-onset proximal, and distal types of HMN were 2.3, 0.6, and 0.6/100,000 respectively. The segregation ratios, 0.26 for acute infantile HMN and 0.24 for chronic childhood HMN, suggested autosomal recessive inheritance. The consanguinity rates among parents of cases and the population did not differ significantly.
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  • 15
    ISSN: 0032-8332
    Keywords: Saimiri ; Human-type ABO blood groups ; Genetics ; Colony management
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The human-type ABO blood groups were determined for 94 families of the squirrel monkey which included 151 animals. Four phenotypes of ABO blood groups (A, B, AB, and O) were detected. Family analysis revealed that the human-type ABO blood groups in this species were governed by three alleles, codominantA andB and silentO. There were intraspecific differences in the distribution of phenotypes and gene frequency among three populations imported by different routes at different times. The usefulness of ABO blood groups for defining the genetic variability of a squirrel monkey breeding colony through successive generations is discussed on the basis of the difference in distribution of ABO blood groups between wild-originated parental and its first colony-born populations.
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  • 16
    Electronic Resource
    Electronic Resource
    Springer
    European archives of psychiatry and clinical neuroscience 237 (1988), S. 244-252 
    ISSN: 1433-8491
    Keywords: EEG ; Genetics ; MZ/DZ twins reared apart ; Within-pair similarity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Within the broader context of our investigations into the heredity of the human EEG, we analysed the EEGs of 28 pairs of monozygotic and 21 pairs of dizygotic twins who were separated as infants and reared apart. The principal goal of this study was to determine the degree to which environmental factors possibly influence the development of a person's EEG. Monozygotic twins reared apart were, with respect to their EEGs, only slightly less similar to each other (if there is any difference at all) than the same person is to himself over time. For dizygotic twins reared apart, we verified the findings of our previous study, namely, that the average within-pair similarity of EEGs estimated from a sufficiently representative sample of fraternal twins was significantly higher than the average inter-individual similarity of EEGs obtained from unrelated persons. The results on both monozygotic and dizygotic twins, yielded conclusive proof that the individual EEG pattern is predominantly determined by hereditary factors.
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  • 17
    ISSN: 1432-2242
    Keywords: Taxonomy ; Germplasm identification ; Varietal identity ; Environmental interaction ; Genetics ; Multivariate analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Separations of kafirin and alcohol soluble glutelin proteins by reversed-phase high-performance liquid chromatography (RP-HPLC) from 7 inbreds and one hybrid of sorghum [Sorghum bicolor (L.) Moench] and one source of Johnsongrass [Sorghum halapense (L.) Pers.] were compared. Objectives were to assess the stability of protein profiles for seed sources produced at different locations and in different environments to examine the potential of RP-HPLC to provide genotypic profiles for sorghum. Analyses of variance data showed that levels of variation due to environments and locations were small; the majority of variation (93%) was among genotypes. Associations among inbreds revealed by multivariate and cluster analysis showed similarity with those that would be expected on the basis of pedigree. A chi-square analysis showed no deviation in the hybrid profile from the expected 2∶1 ratio of peaks from the female and male inbred parents, respectively. Improvements in the ability to correctly assign common peaks are necessary before associations among numerous sorghum genotypes can be reliably demonstrated by analysis of data from reversed-phase high-performance liquid chromatography (RP-HPLC).
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  • 18
    ISSN: 1617-4623
    Keywords: Nicotiana plumbaginifolia ; Nitrate reductase ; Genetics ; Molybdenum cofactor biosynthesis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A total of 70 cnx mutants have been characterized from a collection of 211 nitrate reductase deficient (NR-) mutants isolated from mutagenized Nicotiana plumbaginifolia protoplast cultures after chlorate selection and regeneration into plants. They are presumed to be affected in the biosynthesis of the molybdenum cofactor since they are also deficient for xanthine dehydrogenase activity but contain NR apoenzyme. The remaining clones were classified as nia mutants. Sexual crosses performed between cnx mutants allowed them to be classified into six independent complementation groups. Mutants representative of these complementation groups were used for somatic hybridization experiments with the already characterized N. plumbaginifolia mutants NX1, NX24, NX23 and CNX103 belonging to the complementation groups cnxA, B, C and D respectively. On the basis of genetic analysis and somatic hybridization experiments, two new complementation groups, cnxE and F, not previously described in higher plants, were characterized. Unphysiologically high levels of molybdate can restore the NR activity of cnxA mutant seedlings in vivo, but cannot restore NR activity to any mutant from the other cnx complementation groups.
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  • 19
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 367-380 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: New telechelic ionomers with zinc and sodium sulfate salt terminal groups on hydrogenated polybutadiene (HPB) backbones (I) were prepared from hydroxyl-terminated hydrogenated polybutadiene (HTHPB) of three different molecular weights (1350, 2100, and 3200 g/mol). Quantitative acid-base titration, elemental analysis, and NMR spectroscopy were used to verify the structure, and further characterization included differential scanning calorimetry (DSC) and solution viscometry. The DSC results indicated that the ionomers are free of impurities within the limit of the resolution of the method. Glass transition temperatures determined by DSC indicated that the elevation in glass transition temperature by ionic crosslinking was most strongly dependent on the molecular weight of the backbone of the telechelic ionomer. The solution viscometry results showed that the sulfation reaction did not cause either covalent crosslinking or chain scission. Furthermore, the solubility characteristics of the sulfate-terminated hydrogenated polybutadiene (STHPB) oligomers were shifted towards a preference for polar solvents by the presence of salt groups. The lower molecular weight ionomers of the series showed polyelectrolyte-like extension at very dilute concentrations in polar solvents. The onset of polymer gelation in hexane was observed for the ionomers which had the highest molecular weight backbones.
    Additional Material: 7 Ill.
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  • 20
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 9-18 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Latexes stabilized by poly(N-isopropylacrylamide) (polyNIPAM) were prepared by polymerizing NIPAM in the presence of polystyrene and polystyrene-butadiene latex or by styrene emulsion polymerization in the presence of NIPAM. In 0.01 M CaCl2 polyNIPAM stabilized latexes exhibited critical flocculation temperatures in the range 32-35°C, which is approximately equal to the lower critical solution temperature of polyNIPAM in water. Partial substitution of NIPAM with some acrylamide (AM) gave higher flocculation temperatures. Coagulation studies with cleaned latex indicated that the polyNIPAM or polyNIPAM-co-AM polymer chains were anchored to the latex particle surfaces.
    Additional Material: 5 Ill.
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  • 21
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 43-59 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Copolymers of ethylene and chlorotrifluoroethylene that contain small amounts of units derived from perfluorohexylethylene show improved resistance of thermal stress cracking. This is a consequence of effects of these units on structural parameters of both the crystalline and amorphous phases. Those of the crystalline phase entail growth and organization of lamellae, whereas those of the amorphous phase are related to conformation and packing of polymer chains. The crystalline phase consists exclusively of alternately arranged units of ethylene and chlorotrifluoroethylene. The amorphous phase is characterized by chain segments composed of randomly distributed units derived from ethylene, chlorotrifluoroethylene, pairs of these two units, and units derived from perfluorohexylethylene.
    Additional Material: 17 Ill.
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  • 22
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 615-626 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Natural rubber was isomerized by two methods that involved either dehydrobromination of hydrobrominated natural rubber or heating natural rubber with butadiene sulfone. The 13C-NMR spectra of the methylene region of isomerized natural rubber was interpreted in terms of dyad arrangements for which assignments were made by calculating chemical shifts according to three different published methods. One method [Gronski, Murayama, Cantow, and Miyamoto, Polymer, 17, 358 (1976)] gave the best overall agreement with the experimental chemical shifts; another [Sato, Ono, and Tanaka, Polymer, 18, 580 (1977)] was better for C-1 and C-3 methylene carbon atoms; and still another [Khatchaturov, Dolinsky, Prozenko, Abramenko, and Kormer, Polymer 18, 871 (1977)] gave results which deviated considerably from the other methods. From 13C-NMR intensity measurements it was shown that the elimination of HBr from hydrobrominated natural rubber occurred by a random process. Contrary to literature reports, it was found that the sulphur dioxide catalyzed isomerization of natural rubber was accompanied by a significant amount of double bond migration; a possible reaction scheme was proposed.
    Additional Material: 2 Ill.
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  • 23
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 627-636 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polymeric arylantimony(V) oxides [poly(ArSbO2), Ar = phenyl, p-chlorophenyl (CPh), and p-methylphenyl (Tol)] were employed as catalysts for the polymerization of oxirane [ethylene oxide (EO)] and also substituted oxiranes [propylene oxide (PO), 1,2-butylene oxide (BO), and epichlorohydrin (ECH)]. The polymerization of EO by ArSbO2s proceeded 3-60 times faster than that by the other organoantimony and -tin compounds such as triphenylstibine oxide (Ph3SbO) and arenestannoic acids (ArSnO2H), respectively. Apparent activation energy for the polymerization of EO was estimated as 13.7, 13.3, and 13.6 kcal/mol for PhSbO2, TolSbO2, and CPhSbO2, respectively. The results of the polymerization as well as 1H-, 13C-, and 17O-NMR spectroscopy suggested that the polymerization was initiated by ArSbO2 or Ar2Sb2O4 fragments, which was derived from a nucleophilc solvation of the polymeric ArSbO2 by oxiranes in situ.
    Additional Material: 6 Ill.
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  • 24
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 653-656 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
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  • 25
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 637-651 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The double bonds of natural rubber latex (stabilized by a nonionic surfactant) were reacted with an approximately equimolar amount of performic acid at room temperature with a limited amount of formic acid present. Product analysis by 1H-NMR during the course of the reaction showed that 69-90% epoxidation occurred before the advent of ring opening and ring expansion to produce furanized rubber; hence the rate of epoxidation was greater than the rate of furanization. Indeed, at lower concentrations of formic acid and rubber latex, epoxidation occurred to 90% and furanization was prevented; it was subsequently brought about by the addition of a catalytic amount of orthophosphoric acid. Increased formic acid concentration caused early coagulation of the modified rubber latex. By 1H- and 13C-NMR, it was found that the furanized rubber probably consisted of tetrahydrofuran rings linked together by C—C bonds at positions adjacent to the hetero atom and contained a terminal hydroxy group. The number average sequence length was 2-9, but only the sample with an average sequence length of 9 was effective as a cation binder.
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  • 26
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 657-675 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A number of derivatives of ω-alkenoates were synthesized in preparation for the synthesis of functional polymers based on α-olefins. For the preparation of most of the methyl esters, the regular esterification of ω-alkenoic acids, specifically 10-undecenoic acid with methanol and sulfuric acid as the catalyst, was most effective. For the preparation of the tert-butyl- and 2-ethylhexyl esters of 10-undecenoic acid, the acid chloride route was found to be most convenient, whereas for the preparation of the corresponding esters of 5-hexenoic acid, our method of choice was the synthesis via the imidazolyl derivative of the acid. 2,2,2-Trifluoroethyl 10-undecenoate and the 2,2-dimethyloxazolidine derivative of 10-undecenoic acid were prepared from the acid and 2,2,2-trifluoroethanol or 2-amino-2-methyl-propanol with p-toluene sulfonic acid as the catalyst. Esters of phenol, 2,6-dimethylphenol, and 2,6-diphenylphenol were synthesized from 3-butenoic and 10-undecenoic acid with trifluoroacetic anhydride.
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  • 27
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 235-245 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Aromatic polyamides were prepared from systematically halogenated terephthalic acids with hexamethylene diamine, piperazine, 4,4′-diaminodiphenylether and p-phenylene diamine by interfacial or low temperature solution polycondensation. The halogenated terephthalic acids used have mono-, di-, or tetra-substituted fluorine, chlorine, or bromine atoms on the benzene ring. The nonhalogenated terephthalic acid was also used for the comparison. The effects of halogen substitution on the benzene ring on the synthesis and some properties of polymers were examined. Reduced specific viscosity decreased in the order F 〉 Cl 〉 Br by halogen substitution. The incorporation of halogen substituents on the ring led to a decrease of crystallinity and fluoro-substituents hindered the crystallization more strongly. The melting point (Tm) decreased in the order F 〉 Cl 〉 Br by mono-substitution, and Br 〉 Cl 〉 F by di-and tetra-substitution. The change of Tm caused by the difference of the number of halogen substituents differed depending on the rigidity of polymer chains. The flame-retardancy estimated by thermogravimetry, self-ignition, and flash-ignition test increased with increasing halogen content of the polymers. Solubility increased remarkably by halogen substitution. The peak temperature of tan δ decreased by halogen substitution. Some discussion was made on these effects of halogen substitution.
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  • 28
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 301-311 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The electro-initiated polymerization of acrylonitrile initiated by the anodic oxidation of an aqueous acid solution (80% HOAc + 20% H2O) containing Mn(OAc)2 · 4H2O/CNCH2COOH has been investigated in the 30-40°C temperature range. The kinetics and mechanism of the process has been investigated as a function of variables and a suitable mechanism proposed. From the experimental observations the rate of polymerization is seen to be proportional to [An]1.5I0.5[Mn+2]0.5 and [CAA]0.5. The rate of polymerization gradually decreases at a higher applied current. The rate was independent of [CAA]0.5. The rate of polymerization gradually decreases at a higher applied current. The rate was independent of CAA at high concentration. The average degrees of polymerization (Pn) increases with increasing AN and decreasing [CAA], [Mn+2] and applied current, I. The initiation is due to the anodic oxidation of Mn+2-CNCH2COOH complex. Both the initiation of polymerization by the primary radical, viz., CN—CḢ—COOH as well as the oxidation of the primary radical at the electrode are equally significant reactions and neither can be neglected in comparison with the other. Predominant mutual termination accounts for all the observed data.
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  • 29
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 335-340 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 4 Ill.
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  • 30
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 355-366 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetics and mechanism of polymerization of methacrylic acid (MAA) and ethyl acrylate (EA) initiated by the redox system, Mn3+-thiodiglycolic acid (TDGA) were investigated in the 15-35°C temperature range. The polymerization kinetics of both the monomers followed the same mechanism, viz., initiation by primary radical and termination by Mn3+-thiodiglycolic acid complex. The rate coefficients ki/k0 and kp/kt were related to the monomer reactivity and polymer radical reactivity, respectively. It was observed that both monomer reactivity and polymer radical reactivity followed the same order, viz., EA 〉 MAA. The polymer radical reactivity varied inversely with the Q values of the monomers.
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  • 31
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 247-254 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Diepoxides and in-chain carbonate groups react readily in the presence of quarternary ammonium salts, although reaction is not observed without this catalyst. Two moles of epoxide react with each mole of carbonate. When diepoxides and polycarbonates are reacted, a three-dimensional network of chains crosslinked with carbonate groups is produced; the crosslink density is controlled by adjusting the epoxy/carbonate ratio. Tertiary amines and alkoxides also catalyze the epoxy/carbonate reaction, but these have the undesirable attribute of promoting epoxy polymerization. The presence of oligocarbonates accelerates the epoxy-amine reaction.
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  • 32
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 267-274 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 1-Ethoxy-2,2,2-trifluoroethyl esters of acrylic (I) and methacrylic (II) acids were synthesized from 1-ethoxy-2,2,2-trifluoroethanol and acryloyl- and methacryloylchloride, respectively, and their densities, mass, 1H- and 13C-NMR spectra were measured and the rate constants of hydrolysis were determined. Poly(I) and poly(II) were prepared by radical homopolymerization; the rates of polymerization, specific volume contractions in polymerization, limiting viscosity numbers, average number degrees of polymerization, temperature dependences of the heat capacities both in glass and liquid state, glass transition temperatures, and the initial temperature of the spontaneous thermal decomposition of homopolymers were determined. The monomer reactivity ratios of the styrene (S) copolymerizations, S—I and S—II, and the Alfrey-Price copolymerization constants e and Q for I and II were calculated from the composition of copolymers of I and II with styrene.
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  • 33
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 285-299 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The octameric oligomers of 1-(N-substituted-carbamoyl)-aziridine, i.e., N-ureanized-oligo-ethylenimines, form Cu(II) complexes. When the N-substituents are phenyl(1, 3), methyl(2), and p-tolyl(4) groups, the main portions of the Cu(II)-complexes are binuclear. The binuclear oligomer-Cu(II) complexes showed characteristic properties of photo-reduction of Cu(II) species, giving rise to stable yellow Cu(I) species. The ease of photo reduction strongly depends on the oligomer structures, especially on the nature of the pendant-urea groups, i.e., 4 〉 1,3 〉 2. In the series of aromatic type urea-oligomers, highly stable photo-radicals were observed in ESR. By using an optically active oligomer (3) the molecular requirements for these characteristic properties were investigated with circular dichroism and cyclic voltammometry. And one of the plausible structures was deduced as the model of binuclear Cu(II) sites surrounded by oligomeric environments.
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  • 34
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 321-327 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The copolymerizations of phenyl-4′-vinylphenylbutadiyne (PVPB) with styrene and methyl methacrylate were carried out under various conditions. PVPB was more readily incorporated in copolymerization than the comonomers, but the diacetylenic group of PVPB interacted with the propagating radical, decreasing the polymerization rate and the molecular weight of copolymer. When the polymerization system became very viscous, crosslinking took place giving light green luminescent gels. The thermal behaviors of copolymers were also studied.
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  • 35
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 343-353 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Vinylbenzyl acetate was synthesized in yields greater than 80% via the reaction of vinylbenzyl chloride with potassium acetate. Radical copolymerization of the monomer with styrene and methylmethacrylate were studied at 60°C. Reactivity ratios determined from FT-IR analysis of low conversion copolymerizations with styrene (M1) were r1 = 0.78 ± 0.07 and r2 = 1.33 ± 0.13. Polymers and copolymers of vinylbenzyl acetate were found to completely hydrolyze in dioxane/water/base solution to yield hydroxymethyl functionality. Size exclusion chromatography studies indicated that the hydrolysis proceeded without crosslinking. This procedure is a useful method for the introduction of hydroxyl functionality on polymers and avoids crosslinking problems common in previously reported methods.
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  • 36
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 381-391 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A procedure for the preparation of new block copolymers composed of a hydrophobic block of polystyrene, a hydrophilic spacer-block of poly(ethylene oxide) and a bioactive block of heparin was investigated. Polystyrene with one amino group per chain was synthesized by free radical oligomerization of styrene in dimethylformamide, using 2-aminoethanethiol as a chain transfer agent. This amino group was used in the coupling reaction with amino-telechelic poly(ethylene oxide) to produce an AB type diblock copolymer with one amino group per polystyrene (PSt)-poly(ethylene oxide) (PEO) chain. The amino-semitelechelic oligo-styrene was converted into the isocyanate-semitelechelic oligo-styrene using toluene 2,4-diisocyanate and subsequent coupling with H2N-PEO-NH2 afforded AB type block copolymers with terminal amino groups. The coupling of PSt-PEO-NH2 with heparin was performed in a DMF-H2O mixture, first by activating the heparin carboxylic groups with EDC at pH 5.1-5.2 and subsequently reacting the activated carboxylic groups with the amino groups of the PSt-PEO-NH2 at pH 7.5. Depending on the molecular weights of the diblock copolymer used 25-29% w/w heparin was incorporated. These polymers will be further evaluated for their blood-compatibility.
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  • 37
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 419-427 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In order to obtain polysiloxanes capable of forming a film, the preparation and properties of allyldimethylsilylated silicic acid was investigated. The reaction in variable molar ratios of allyldimethylchlorosilane to silicic acid gave partially silylated silicic acids with different degrees of silylation. They provided not only fibrous polysiloxanes but also films from concentrated polymer solutions. Spinnability and film formation depended on the solvent, degree of silylation, molecular weight, and allyl group.
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  • 38
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 457-464 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Supports were obtained by the interaction of C4H9MgCl with the reaction mixture of AlCl3 and CH3Si(OC2H5)3 or Si(OC2H5)4 (Mg/Al/Si = 2/1/1). With the combination of Al(C2H5)3 and methyl-p-toluate, immobilized titanium catalysts prepared by the treatment of the supports with TiCl4 and ethylbenzoate showed extraordinary high activity and stereoregularity in the polymerization of propylene.1 By the study of the reaction of AlCl3 with CH3Si(OC2H5)3, the elemental analysis and powder x-ray diffractometric measurements of the supports, it was found that the supports comprised of Cl, Mg, Al, and Si atoms, OC2H5 groups, C4H9 groups, and ethers, and that they were amorphous solids to the extent that the x-ray diffraction peak assigned to the 003 plane in MgCl2 crystals completely disappeared.
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  • 39
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 901-911 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The effect of various substituted amines on the polymerization of methyl methacrylate initiated by ferric laurate - amine as the initiator system has been studied in carbon tetrachloride medium at 60°C. Amines used are n-butyl amine, di-n-butyl amine. The rate of polymerization is found to follow the order: tertiary 〉 secondary 〉 primary amine. From the detailed kinetic studies it was found that the overall polymerization rate can be expressed by the equation: \documentclass{article}\pagestyle{empty}\begin{document}$ R_p = \frac{{k_p }}{{k_t^{{1 \mathord{\left/ {\vphantom {1 2}} \right. \kern-\nulldelimiterspace} 2}} }}(k_1 f)^{{1 \mathord{\left/ {\vphantom {1 2}} \right. \kern-\nulldelimiterspace} 2}} [{\rm Monomer}][{\rm Fe}^{3 + } ]^{{1 \mathord{\left/ {\vphantom {1 2}} \right. \kern-\nulldelimiterspace} 2}} [{\rm Amine}]^{{1 \mathord{\left/ {\vphantom {1 2}} \right. \kern-\nulldelimiterspace} 2}} $\end{document} The relative activity of the different amines has been found to be dependent on the relative electron-donating tendency of the substituents present in the amine. The mechanism of the polymerization is discussed on the basis of these results, and various kinetic constants are evaluated.
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  • 40
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 959-962 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
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  • 41
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 965-971 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A general method for estimating kinetic parameters in polymerization reactions using Monte Carlo simulation to represent the models of the reactions is developed. From a statistical point of view, the procedure is a Bayesian one in which a posterior probability density surface (PPDS) is calculated for points on a grid in the parameter space. A smoothing function is fitted to the PPDS, then a posterior probability region, which is similar to a confidence region, is calculated for the parameters. An application to a relatively trivial example, the Mayo-Lewis copolymerization model is shown in detail. Many other potential applications are suggested.
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  • 42
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 2345-2354 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: High performance linear AA-BB and A-B polyamides were generated using polymerization schemes that gave polymers in higher yields and having better performance than previous methods. Polymers were characterized with FTIR, solution and solid-state 13C-NMR and showed the incorporation of aryl, alkyl, and alkenyl linkages in the polymer backbone. Thermal analysis showed that a significant weight percent of the polymers remained at 1000°C.
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  • 43
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 865-883 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A novel route for the thermal conversion of bis(phthalonitrile)monomers into metal-free phthalocyanine network polymers was investigated on the basis of a model study on the tetramerization reaction of 4-benzoylphthalonitrile and benzhydrol derivatives into metal-free phthalocyanine compounds. This procedure of conversion of phthalonitrile derivatives involved an oxidoreduction reaction initiated by the alcohol functional group of benzhydrol coreactant. The influence of molar ratio of phthalonitrile and benzhydrol functional groups, chemical environment of the benzhydrol reducing group has been studied by microcalorimetry and electronic spectroscopy. It was observed that the theoretical 4 : 1 phthalonitrile: benzhydrol molar ratio is respected and the reductive capacity of the benzhydrol group is increased by the electron withdrawing effect of its substituants.
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  • 44
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 885-900 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: New phosphorus-containing homopolyurethanes were synthesized by reacting various diisocyanates such as tolylene diisocyanate, methylenebis(4-phenylisocyanate) and hexamethylene-1,6-diisocyanate with 1,4-bis[(dialkoxyphosphinyl)hydroxymethyl]benzene (BDAB). In addition, copolyurethanes containing approximately 3% phosphorus were prepared by copolymerization of these diisocyanates with an equimolar amount of BDAB - hydroquinone mixture. BDAB was less reactive towards diisocyanates than hydroquinone due to the electron-withdrawing inductive effect of the phosphinyl groups. The polymers synthesized were characterized by inherent viscosity measurements as well as by proton nuclear magnetic resonance (1H-NMR) and infrared (IR) spectroscopy. The spectroscopic examination of polymers did not provide evidence for crosslinking by allophanate groups. Differential thermal analysis (DTA) studies of polymers revealed that the incorporation of BDAB in polyurethanes altered their thermal decomposition mode by increasing the exothermicity due to pyrolysis. Thermogravimetric analysis (TGA) of polymers showed that the phosphorus-containing homopolyurethanes and copolyurethanes were thermally less stable than the corresponding common polyurethanes but afforded higher char yields. Determination of the limiting oxygen index (LOI) values showed that the phosphorus-containing copolyurethanes exhibited a higher fire resistance than that of common polyurethanes.
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  • 45
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 953-958 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
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  • 46
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 1903-1909 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polar organic compounds either (1) inhibit the peroxide-catalyzed bulk homopolymerizations of both MAH and MMA at 80°C, (2) do not inhibit the polymerization of either MAH or MMA, or (3) inhibit the polymerization of MAH but not that of MMA. Compounds generally used as polymerization inhibitors or antioxidants inhibit the polymerizations of both MAH and MMA, presumably by interaction with peroxide decomposition products. Ketones, ethers, acids, esters, nitriles, imides, sulfones, sulfonates, sulfonamides, and acyl disulfides do not inhibit either MAH or MMA polymerization. However, amides, lactams, carbamates, amine oxides, phosphites, phosphates, phosphonates, phosphoramides, phosphine oxides, monosulfides, sulfoxides, aryl disulfides, and thiazyl disulfides inhibit the polymerization of MAH but not that of MMA. Inhibition presumably occurs as a result of electron transfer from the nitrogen-, phosphorous- or sulfur-containing electron donor compound to the MAH carbocation which is an intermediate in the polymerization of MAH.
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  • 47
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 1911-1918 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polymerization of tetrahydrofuran (THF) (bulk) promoted by a free radical source, 2,2-dimethoxy-2-phenyl acetophenone (DMPA), in the presence of 4,4′-di-(methylphenyl)iodonium hexafluorophosphate was studied in detail. Rate dependence of the polymerizing system on both DMPA and the iodonium salt was studied dilatometrically. Rate saturation for the iodonium salt was attributed to the formation of iodobenzene, which may react with propagating cations to form an iodonium salt. DMPA was shown to be an efficient transfer agent in the cationic polymerization of THF. A transfer constant for DMPA was estimated to be 2.8 and, whilst the precise details of the overall mechanism cannot be deduced from the present results, it may result in functionalized polytetrahydrofuran chains having photochemically active end groups.
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  • 48
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 1919-1935 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The use of the solvent mixture chloroform/hexafluoroisopropanol (98 : 2 vol %) in the GPC-analysis of polyethylene terephthalate (PET) is described. PET-samples of different molecular weight have been prepared and characterized by light scattering, viscometry, and improved techniques of osmometry and end group titration. These well characterized samples were used in calibrating the GPC. The calibration with polydisperse standards was found superior to the universal calibration procedure in the solvent system chosen.
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  • 49
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 1937-1959 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Batch emulsifier-free copolymerizations of styrene (S) and butyl acrylate (BuA) have been performed for a S/BuA weight ratio = 50/50 in the presence of two types of functional comonomers [methacrylic acid (MAA) at different pHs] or potassium sulfopropylmethacrylate (SPM) and two initiators [potassium persulfate or 4-4′azobiscyanopentanoic acid (AZO)]. The use of AZO/MAA system results in the formation of polymer particles with only surface carboxylic end groups. The particle size of the final latexes can be adjusted with the MAA concentration, provided the polymerization is carried out at pH 〉 6.5. However, the higher the MAA concentration, the sooner the polymerization levels off in conversion. With the K2S2O8/SPM system, particles bearing only sulfate and sulfonate groups are produced and the polymerization is complete. In that case, the particle size of the final latexes is smaller than with the previous system and 30% of the SPM is fixed on the particle surface, instead of 10% with MAA. Using SPM, a too high functional monomer concentration results in the latex destabilization caused by the formation of a large amount of polyelectrolytes. Kinetic studies indicate that most of the functional monomer is incorporated onto the particle surface during the last 30% conversion of the polymerization. A tentative explanation of such a behavior is discussed, based on the existence of two polymerization loci in the latex system.
    Additional Material: 12 Ill.
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  • 50
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 2517-2527 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Four linear polyesters containing styrylpyridinium units were prepared from 2,6-bis(p-hydroxystyryl)pyridine and terephthalic acid, isophthalic acid, adipic acid, and sebacic acid, respectively. The polyesters are thermally stable in the 365 to 450°C range. The decomposition temperature is higher for aromatic polyesters, lower for their aliphatic analogs. The polyesters are photoreactive and crosslink on irradiation with UV. The crosslinking mechanism is 2 + 2 cycloaddition. The polyesters form protonated complexes with CF3COOH which absorb at longer wavelengths and are also photoreactive. The quantum yield of the photoreaction and the relative photosensitivities of the polyesters and their complexes were determined.
    Additional Material: 6 Ill.
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  • 51
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
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  • 52
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 1051-1061 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Novel polybenzimidazoles containing thiaxanthone heterocyclic units were synthesised from 2,7-thiaxanthonedicarboxylic acid-5,5′-dioxide and 2,8-thiaxanthonedicarboxylic acid-5,5′-dioxide and two aromatic tetramine hydrochlorides by PPA solution polycondensation in 60-70% yield. Two model compounds, 2,7-bis(2-benzimidazolyl)thiaxanthone-5,5′-dioxide and 2,8-bis(2-benzimidazolyl)thiaxanthone-5,5′-dioxide, were prepared and characterized by spectral methods. The polybenzimidazoles have inherent viscosities in the range 1.13-1.50 dL/g and decomposition temperatures of 495-560°C. The effect of thiaxanthone units on polymer properties are discussed.
    Additional Material: 5 Ill.
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  • 53
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 1063-1076 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Novel polyamides containing heterocyclic thiaxanthone units were prepared by condensing 2,7-dichloroformylthiaxanthone-5,5′-dioxide and 2,8-dichloroformylthiaxanthone-5,5′-dioxide with various aromatic diamines, under low temperature solution polymerization conditions in DMAc. The model diamide, 2,8-ditolylcarbamylthiaxanthone-5,5′-dioxide was synthesised and characterized by spectroscopic methods. The polyamides were prepared in 70-80% yield and had inherent viscosity in the 0.36-0.73 dL/g range. The poyamides have decomposition temperatures in the 425-510°C range in nitrogen. The effect of thiaxanthone rings on polymer backbone on solubility, crystallinity, and thermal stability is also discussed.
    Additional Material: 8 Ill.
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  • 54
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 1985-1988 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
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  • 55
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 1991-2002 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Styrene/p-hydroxystyrene copolymers were prepared from copolymers of styrene and p-benzyloxystyrene by cleavage of the ether bond. Nuclear magnetic resonance spectroscopy was used to characterize the polymers before and after the ether cleavage reaction. Reactivity ratios were calculated by applying the method of least squares to data generated from the Fineman-Ross equation (r1 = 0.37, r2 = 0.28). The surface chemistry of centrifugally cast films of the homopolymers and the copolymers was studied by using electron spectroscopy for chemical analysis (ESCA). The Zisman contact angle method was used to determine the critical surface tension in air for each polymeric surface. Water contents of hydrated films were determined gravimetrically. The polar character of the surface was shown to increase to a small degree with an increase in the p-hydroxystyrene component. Polymers with high p-hydroxystyrene contents did not exhibit pronounced hydrogel character.
    Additional Material: 8 Ill.
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  • 56
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 2003-2018 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Two series of catalysts were made, one from MgCl2-A solution containing MgCl2, EH (2-ethylhexanol), and EB (ethyl benzoate) dissolved in decane and another from MgCl2-B solution containing MgCl2, EH, and phthalic anhydride which reacted to form the corresponding phthalic ester. Reactions of these solutions with TiCl4 with or without another ester produced a family of eight catalysts. They form two groups, one having monoesters as modifiers, and the other containing diesters as modifiers. The surface area, pore volume, x-diffractions, polymerization activity, and catalytic stereospecificity of these catalysts have been compared. The diester catalysts differ from the monoester catalysts in every respect. By comparison the corresponding member of the diester catalysts have half as much Ti per Mg, more than 10 times the pore volume, more than a 100-fold the surface area, about 50% more productivity, and greatly increased steroespecificity.
    Additional Material: 9 Ill.
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  • 57
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 2019-2029 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A soluble monomer [methyl acrylate (MA)] and an insoluble monomer [butyl methacrylate (BMA)] were grafted onto cellulose by three types of ceric salts under both oxygen-free conditions and in the presence of oxygen. For comparison, Ce(IV) consumption during cellulose oxidation was also determined under similar reaction conditions. Slightly more Ce(IV) was consumed during cellulose oxidation in the presence of oxygen. During graft copolymerization of MA under oxygen-free conditions, the consumption of Ce(IV) was much lower than during cellulose oxidation regardless of the type of ceric salt employed. The opposite was observed in the presence of oxygen: much more Ce(IV) was consumed during grafting than during cellulose oxidation. The consumption of Ce(IV) in the graft copolymerization of BMA by ceric sulfate was nearly independent of reaction conditions and it was approximately the same as in cellulose oxidation. In the reaction initiated by ceric ammonium nitrate under oxygen-free conditions, less Ce(IV) was once again used up during grafting than during cellulose oxidation. However, the difference was much smaller than in the case of MA.
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  • 58
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 2031-2037 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The functionalization reaction of poly(styryl)lithiums (Mn = 1.3-9.9 × 103) with ethylene oxide in benzene proceeds quantitatively ( 〉 99%) to produce the corresponding hydroxyethylated polymer as determined by vapor phase osmometry, size exclusion chromatography, end-group titration, thin layer chromatography, and 1H- and 13C-NMR spectroscopy. 13C-NMR spectral analysis of the functionalized polystyrene with Mn = 1.3 × 103 was consistent with addition of only one ethylene oxide unit to poly(styryl)lithium, i.e., no evidence for ethylene oxide oligomerization was observed.
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  • 59
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 1671-1675 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
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  • 60
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 1649-1657 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Molecular weight studies of polyamic acids are complicated by polyelectrolyte effects. Although early work on the molecular weight determination of polyamic acids employed salts to suppress this polyelectrolyte effect, recent publications reveal that such salts can cause precipitation of polyamic acids from solution, however, a mobile phase consisting of 0.03M LiBr/0.03M H3PO4/1% vol THF in dimethyl formamide was reported to successfully suppress the noted polyelectrolyte effect without causing the precipitation of polyamic acid and give satisfactory size exclusion chromatograms using columns packed with “macro-porous” glasses. However, the development time was long (ca. 4 h) and considering the lability of the polyamic acids, the results must be viewed with skepticism. We find that use of a similar “mixed” mobile phase with Zorbax® PSM-Bimodal columns using size exclusion chromatography in the high performance mode (HPSEC) provides well resolved and reproducible chromatograms and molecular weight data with development times of 〈 15 min. Aside from the avoidance of long development times, which can lead to questionable results, this procedure permits the facile routine analysis of polyamic acid on a daily basis. The procedure has great utility as an analytical tool to support fundamental studies of polyamic acid chemistry and two examples of this application are given.
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  • 61
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 1677-1680 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
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  • 62
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 1659-1669 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Preparation of two model polymers of polynucleotides with linear polyurethane backbone and 2-(thymin-1-yl)propionyl or 2-(uracil-1-yl)propionyl group as grafted pendant are described. 2-(Thymin-1-yl)propionic acid (TPA) and 2-(uracil-1-yl)propionic acid (UPA) were grafted into partial imino functionalized polyurethane, poly[(β,β′-diethylene)amine methylene bis(4-phenylcarbamate)]-75 (PU-NH-75), at the secondary amino group through amide bonds with 1-hydroxybenzotriazole (HOBT) using the active ester technique. Two novel polymer models of polynucleotides, poly[(N-(2-(thymin-1-yl)propionyl)-β,β′-diethylene)amine methylene bis(4-phenylcarbamate)]-75 (PU-NT-75) and poly[(N-(2-(uracil-1-yl)propionyl)-β,β′-diethylene)amine methylene bis(4-phenylcarbamate)]-75 (PU-NU-75) were obtained. The imino polyurethane PU-NH-75 was produced from the partially deprotected N-Cbz imino polyurethane, poly[N-(benzyloxycarbonyl-β,β′-diethylene)amine methylene bis(4-phenylcarbamate)] (PU-NCbz) which was prepared by the polyaddition of 4,4′-diphenylmethane diisocyanate (MDI) with diol monomer N-benzyloxycarbonyl-β,β′-dihydroxyethylamine (CbzHEA). Selective N-protection of N-benzyloxycarbonyloxy-5-norbornene-2,3-bicarboximide (CbzONB) with β,β′-dihydroxyethylamine (HEA) gave the N-Cbz protected diol monomer HEA. The related monomer model compounds were also prepared by the same methods.
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  • 63
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 1189-1198 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The crosslinking of LDPE resulting from reaction with dicumyl peroxide at 180°C is increased in the presence of maleic anhydride (MAH). The presence of electron-donating nitrogen-containing compounds (amides, lactams, disubstituted aromatic amines, and amine oxides), phosphorous-containing compounds (phosphites, phosphates, phosphonates, phosphoramides, and phosphine oxides) and sulfur-containing compounds (sulfoxides, aryl disulfides, and thiazyl disulfides) which inhibit the homopolymerization of MAH but not that of methyl methacrylate, prevents crosslinking and yields soluble PE containing MAH units. Crosslinking, due to coupling of PE· macroradicals formed by hydrogen abstraction from PE by excited MAH, is prevented by electron donation from the additive to the MAH+ cation which is present in the MAH+-MAH excimer as well as in the excimer which is appended to the PE.
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  • 64
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 1179-1188 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The diffusion coefficient of oxygen in poly(2-hydroxyethyl methacrylate) has been explicitly measured using an optical technique based on fluorescence quenching. This measurement represents the first explicit determination of DO2 in PHEMA. A diffusion coefficient of oxygen in PHEMA of 1.36 × 10-7 cm2/s at 20°C was obtained from this measurement. This value is shown to agree well with permeability data for PHEMA, the free volume theory of diffusion, and with values of DO2 that have been explicitly measured in other methacrylate hydrogels.
    Additional Material: 4 Ill.
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  • 65
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 2099-2111 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Surfaces of low density polyethylene, high density polyethylene, and polystyrene have been modified by grafting with acrylic acid. Benzophenone and acrylic acid in the vapor phase were UV-irradiated in the presence of a polymer substrate. Grafting with acrylic acid took place in a thin layer on the surface, thus increasing the wettability of the polymer. After 5 min of irradiation, the contact angle against water had decreased to 20° for polystyrene and 50° for the polyethylene samples. ESCA measurements on samples irradiated for 5 min showed a 90% poly(acrylic acid) coverage of the surface for polystyrene, 63% for low density polyethylene, and 56% for high density polyethylene. Acetone or ethanol were used as carriers of monomer and initiator. Acetone was able to initiate grafting and was found to promote and direct grafting to the surface. The stability of the acrylic acid grafted surfaces was studied by contact angle measurements and ESCA. At room temperature, the grafted layer is confined to the surface, but when the material was heated in air the surface was reshaped into a hydrophobic one. The process was reversible. In aqueous surroundings at elevated temperatures the hydrophilic character of the surface was restored.
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  • 66
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 2859-2862 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
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  • 67
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 2873-2880 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ESCA has been used to characterize films deposited from perfluorobenzene and perfluorobenzene/benzene vapors during plasma polymerization and irradiation with vacuum ultraviolet light. The films deposited by both methods are shown to be essentially the same. This indicates that similar electronically excited states are involved in the formation of the precursors to deposition in both methods and that reaction mechanisms involving ions do not need to be considered for the plasma polymerization of the monomers investigated.
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  • 68
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 2899-2905 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Novel phenyl-pendant aromatic polythiazoles having inherent viscosities of 0.3-1.3 dL/g were synthesized by the solution polycondensation of bis[4-(α-bromophenylacetyl)phenyl] ether with aromatic dithioamides or dithiooxamide in dimethylformamide at 60°C. The polythiazole having m-phenylene linkage was readily soluble in chloroform and m-cresol, and transparent flexible film could be cast from the chloroform solution. Glass transition temperatures of these polythiazoles were in the range of 210-250°C. They started to decompose at about 500°C in air with 10% weight loss being recorded at around 570°C.
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  • 69
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 2917-2922 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Aromatic polyamides (aramids) having inherent viscosities of 0.5-1.10 dL/g were prepared by the direct polycondensation of 1,1,3-trimethyl-3-(4-carboxyphenyl)indane-5-carboxylic acid with various aromatic diamines using triphenyl phosphite and pyridine as the condensing agents. Copolyamides were also prepared by a similar procedure from a mixture of the phenylindane diacid, terephthalic acid, and p-phenylenediamine. Almost all of the aramids were soluble in a variety of solvents such as N-methyl-2-pyrrolidone, pyridine, and m-cresol, and afforded transparent and tough films by the solution casting. These aramids and copolyamides had glass transition temperatures in the range of 290-355°C, and started to lose weight at 340°C in air.
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  • 70
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 2941-2952 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Model reaction of bis(4-nitrophenyl) β-truxinate (BNPT) with aliphatic amines proceeded quantitatively at room temperature. Accordingly, polycondensation of BNPT with various diamines was carried out at room temperature or 80°C. During the polycondensation of BNPT with diamines, the precipitation of polymer or the observed gelation of polymerization solution occurred, which may limit the molecular weight of the polymer. On the other hand, the reaction of BNPT with 1,3-(4-piperidyl)propane (DPP) proceeded homogeneously to give the polymer with relatively high molecular weight, and the obtained polyamide (P-1e) showed excellent solubility in many solvents. The study of TG and DTA indicated that the obtained polymers were stable at lower temperature than around 270°C. The polymer prepared from the polycondensation of BNPT with hexamethylenediamine showed melting point and decomposition due to the imidation at 282°C. The photochemical reaction of these polymers was carried out in the film state. The irradiation of 254 nm light caused an absorption at 272 nm to appear and the molecular weight to decrease. This meant that the scission of cyclobutane ring in the main chain occurred to give cinnamamide structures. Also, the absorption at 272 nm decreased by the irradiation of 302.5 nm light. However, the UV spectrum of irradiated polymer did not agree with that of the original polymer. These results suggested that the dimerization of the resulting cinnamamide moieties occurred in the competition of their trans-cis-isomerization. On the other hand, the rate of scission of cyclobutane ring of P-1e was faster than that of the corresponding polyamide containing α-truxillamide structure.
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 2991-2996 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Fluorine-containing graft copolyamides were prepared from condensation-type macromonomers. Dicarboxyl-terminated poly(perfluoroalkylethyl acrylate) was prepared by radical chain transfer polymerization and copolycondensed with diamines and dicarboxylic acids in the presence of triphenylphosphine and pyridine. Nylon-6 films containing various amounts of the resulting graft copolyamides were obtained by heat pressing. Only 5 wt % of graft copolymers were sufficient to make nylon-6 surfaces water repellent.
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  • 72
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    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 3031-3042 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 1-Phenylethyl trifluoroacetate (1) does not react directly with styrene but it is readily incorporated into polymer chains in the presence of an excess of trifluoroacetic acid. The proportion of the nondeuterated 1-phenylethyl end groups in the polymerization of deuterated styrene coinitiated with the acid was much higher than the proportion of the end groups formed by direct incorporation of the acidic protons ([CH3—CHPh—CD2—CDPh— …] 〉 [HCD2—CDPh—CH2—CDPh— …]). The racemization of the optically active ester-(pseudo-first order rate constant at [HA]0 = 0.79 mol/L at 20°C equals kR = 1.7 × 10-4 S-1) is more rapid than the incorporation of the ester into polymer chains (kE = 1.5 × 10-4 mol-1 Ls-1, [M]0 〈 0.4 mol L-1, i.e., kR 〉 kE · [M]). These results and the complete loss of the optical activity in the final polymer indicate that the ester is activated by the acid but it is incorporated into polymer chain via ionic intermediates.
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 3043-3069 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Block copolymers of poly(N-isovaleryl ethyleneimine) (PiVEI) and poly(ethylene glycol) (PEG) were synthesized by coupling previously prepared blocks of PEG ditosylate with the dianion of the dihydroxy PiVEI. On the average four blocks coupled together to form the final block polymer. The PiVEI blocks crystallized with the same melting points as in the homopolymer. This restricted the mobility of the PEG blocks and they did not crystallize unless cooled well below room temperature. The mechanical properties of cast films were quite good with a tensile strength of 77 kg/cm2 and an elongation of 120%. The swelling of unoriented and oriented films with water was studied. The unoriented polymer absorbed about its own volume of water, even though PEG comprised only 40% of the total polymer.
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 3089-3102 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ethylene was polymerized by Cp2ZrCl2-methylaluminoxane (MAO) catalysts where a portion of the MAO was replaced with trimethyl aluminum (TMA). At a total Al to Zr ratio of 1070, there is neither appreciable loss of productivity nor change in polymerization profile for TMA/MAO ≤ 10. The productivity is reduced only by two- to three-fold for TMA/MAO ≤ 100 accompanied by a 10 min induction period. Aging of this catalyst did not affect the induction period, but improves its productivity. The kinetic isotope effect for radiolabeling with tritiated methanol is 2.0. About 40% of the Zr is active for the catalyst with {99 [TMA] + 1[MAO]} to Zr ratio of 100. The rate constants for propagation and chain transfer were obtained. The mechanisms for the mixed TMA and MAO cocatalyst system are discussed. The results of this work have important practical significance. MAO is a hazardous material to synthesize and only in low yields. The replacement of 〉 90% of MAO with TMA represents a substantial saving since as much as 0.1M of the former is commonly used for a polymerization.
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  • 75
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 1307-1314 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The title polymers were synthesized and the oxygen permeation behavior through the polymer films were studied. The oligodimethylsilane-substituted polystyrenes showed a little low Po2 compared with the oligodimethylsiloxane-substituted polystyrenes. The important role of trimethylsiloxyl group in permeation was suggested.
    Additional Material: 1 Ill.
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  • 76
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 1315-1322 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The pyrolyses of homologous poly(alkyl acrylate)s is reported with identification of the major pyrolyses products. A mechanism involving random homolytic scission of the chain followed by a series of intermolecular and intramolecular transfer reactions has been proposed for poly(methyl acrylate) by Cameron and Kane and further developed by Haken, Ho, Houghton, and Gunawan. This mechanism is demonstrated to be generally applicable to the poly(n-alkyl acrylate)s. Reaction mechanisms are postulated for the various products produced and ion fragmentation mechanisms for the mass spectra produced are shown.
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  • 77
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 1335-1341 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Schiff base (SB) monomers of vinylbenzaldehyde with functional amines were prepared. Copolymers of SB monomers with N-vinyl-2-pyrrolidone soluble in aqueous solutions were obtained in most cases. However, p-aminobenzenesulfonamide monomer resulted in gel formation. Thus, the reaction of vinylbenzaldehyde copolymer with the sulfonamide was used instead of the copolymerization. The hydrolytic behaviors of SB monomers and copolymers to liberate respective amines were structure dependent and, for most copolymers, the rates were lower than those of the corresponding monomers.
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  • 78
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 1323-1334 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetics of the reaction between atactic polypropylene (APP) and oxygen in bulk at temperatures ranging from 170 to 210°C and oxygen partial pressures from 160 to 760 torr have been studied by thermal differential analysis. The reaction takes place in two successive steps, both giving hydroperoxide groups as product. Partial reaction orders with respect to APP and oxygen for the first step, which corresponds to the uncatalyzed attack of a C—H tertiary bond to give a hydroperoxide, are one and two, respectively. In the second step, interpreted as another attack on a tertiary C—H by oxygen, catalyzed by a neighboring hydroperoxide group, reaction orders are one and one-half for APP and oxygen, respectively. Activation parameters have been determined and a reaction sequence is proposed. Hydroperoxidated APP subsequently decomposes via a zero-order process giving methylketone groups as its main product. An interpretation of this process is also given.
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  • 79
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 3189-3198 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: α-Methoxyphenylmethylium hexachloroantimonate was prepared from α-methoxybenzyl chloride and antimony pentachloride at 0°C and isolated for the first time, and its visible and 1H-NMR spectra were measured. This salt was used as a novel initiator for the polymerization of propylene oxide (PO) in the temperature range -20 to 30°C with dichloromethane as solvent. PO polymerized spontaneously but a limit yield was observed. The microstructure of PO polymer is amorphous by 13C-NMR. The PO polymerization is thought to proceed in the conventional cationic mechanism on the basis of the polymerization behavior and the analyses of both the polymer structure and end groups attached to the PO polymer.
    Additional Material: 5 Ill.
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  • 80
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 1377-1391 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The effects of carbon blacks, chopped carbon fibers, and crushed carbon fibers on the crosslinking chemistry of a diglycidyl epoxy resin/m-phenylenediamine system were examined by infrared (IR) spectroscopy and differential scanning calorimetry (DSC). The carbon and graphite surfaces were given oxidizing and reducing treatment to simulate the surface treatment of carbon fibers used in the manufacture of composites. The oxidized carbon surfaces initially accelerated epoxy-amine reactions but inhibited the later stages of the reaction such that the final extent of cure was reduced. The oxidized carbons also preferentially adsorbed the amine curing agent, resulting in a stoichiometric imbalance at the interface.
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  • 81
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 1361-1376 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Cyanoacetamides are a novel class of curing agents for epoxy resins. Since reaction products of epoxy compounds with cyanoacetamides have not yet been described, we investigated the reaction of phenyl-glycidylether (PGE) and N-isobutylcyanoacetamide (NICA) under the conditions of the epoxy cure (120-150°C). Twenty-two fractions of the reaction product have been separated by preparative TLC and characterized by FD and MS mass spectroscopy. The structures of 10 reaction product have been elucidated by MS, NMR, and IR techniques. They belong to the classes of cyclic urethanes, spiro-dilactones, cyclo-oxa-1-hepten-4-one-2, pyrimidones, aminocrotononitrile, and tertiary amine. This complex model reaction mixture does not enable us to propose a curing mechanism. However practical cure of Bisphenol A diglycidylether (BADGE) yields clear and tough solids with a glass transition temperature up to 200°C, good mechanical strength, and high adhesion to metal surface. Cyanoacetamides are latent hardeners requiring a curing initiator. Since N-4-chlorophenyl-N′-dimethylurea is a latent initiator, liquid, homogeneous, storage stable “one shot” systems can be formulated which harden quickly above 120°C. Heat aging properties of cured specimens are reported. A series of novel liquid, resinous, and crystalline cyanoacetamides and their potential as curing agent are described.
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  • 82
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 1393-1404 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A homologous series of copolyether-urethane-ureas were synthesized with polypropylene glycol segments having molecular weights of approximately 200, 400, 700, 1000, 2000, and 3000. These copolymers were characterized using tensile measurements and dynamic mechanical spectroscopy. The dynamic mechanical measurements at low frequencies (≤ 1 Hz) showed evidence of the existence of an α-relaxation process. This was attributed to constrained polyether segments located at the interfacial region between the hard urea segments and the soft polypropylene glycol segments.
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  • 83
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 1405-1418 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Novel phosphorylated bismaleimides and nonphosphorylated tetramaleimides containing substituted s-triazine rings (chain-extended by imide, amide, or urea groups) were prepared and polymerized. These polymer precursors were prepared by reacting 2,4-bis(4-aminophenoxy)-6-diethoxyphosphinyl-s-triazine or 2,4,6-tris(4-aminophenoxy)-s-triazine with maleic anhydride in combination with a bridging agent such as pyromellitic or benzophenone tetracarboxylic dianhydride, terephthaloyl chloride, and tolylene diisocyanate. The structure of polymer precursors was confirmed by infrared (IR) and proton nuclear magnetic resonance (1H-NMR) spectroscopy and their curing behavior was investigated by differential thermal analysis (DTA). The phosphorylated bismaleimides were thermally polymerized at a lower temperature than did the corresponding nonphosphorylated tetramaleimides. Dynamic thermogravimetric analysis (TGA) showed that the nonphosphorylated and phosphorylated cured resins were stable up to 320-370 and 312-327°C, respectively, in nitrogen or air atmosphere. In addition, the latter afforded a relatively higher char yield. The relative thermal and thermooxidative stability of polymers with regard to the chemical structure of the bridging group was of the order imide 〉 amide 〉 urea. Upon isothermal aging the phosphorylated polymers exhibited a lower weight loss than did the corresponding nonphosphorylated polymers.
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  • 84
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 1419-1428 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The solid state of the complex between poly(acrylic acid) (PAA) and poly(ethylene oxide) (PEO), and that between poly(methacrylic acid) (PMAA) and PEO formed via hydrogen-bonding was studied by differential-scanning calorimetric (DSC) and by Fourier-transform infrared (FT-IR) spectroscopic measurements. Melting temperature Tm and the degree of the crystallinity Xc of PEO in the systems PAA (or PMAA)/PEO blends obtained from aqueous or dimethyl sulfoxide (DMSO) medium were measured in various unit mol % of PEO ([PEO]100/{[PAA(or PMAA)] + [PEO]}) where [ ] is the unit mole concentration. It was found that 50 unit mol % of PEO is a critical composition, which gives new evidence for the 1 : 1 complex formation between PAA (or PMAA) and PEO. From the FT-IR spectroscopic analysis in conjunction with DSC measurements we also found that the effects of solvent and of hydrophobic interaction (due to the α-methyl group of PMAA) are the important factors controlling the complexation in the solution and solid systems. These factors also affect the crystallization behavior and the microstructure of the PAA (or PMAA)/PEO blend in solid state.
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  • 85
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 1439-1456 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The compositions and sequence distributions of homogeneous styrene (S)-ethyl methacrylate (E) copolymers, obtained by low conversion solution polymerization have been studied by 1H- and 13C-NMR. A new set of peak triad assignments was proposed for the δ 2.1-4.2 ppm region in the 1H-NMR spectrum, whereby the reactivity ratios of rS = 0.59 and rE = 0.50 were used to establish this new assignment. The EEE and SSS blocks, present in these copolymers, have a high degree of syndiotacticity (σEE = 0.23, σSS = 0.39), whereas the ESE units are exhibiting a slight tendency toward isotacticity (σES = 0.66).
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  • 86
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 1429-1438 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetic behavior of the thiyl radical in the solution containing polyisoprenes and polybutadienes has been studied by the flash photolysis method. For benzothiazole-2-thiyl radical, the addition rate constants toward these polymers and the model compounds of the polymers were evaluated. The relative reverse rate constants and equilibrium constants were also estimated. The addition rate constants decrease with an increase in the degree of polymerization; the ratio of the addition rate constant for polyisoprene (3.1 × 104 M-1 s-1 (in monomer unit); Mv = 674,000) to that for 2-methyl-2-butene (1.5 × 105 M-1 s-1) is about 1/5. This indicates that the polymer chain effect appears in the free-radical addition reaction. The relative reverse rate constants for the polymers are also smaller than those for 2-methyl-2-butene, suggesting a kind of polymer effects; i.e., it can be presumed that the bonded-thiyl radicals migrate very rapidly to the neighboring double bonds in the polymer. Significant differences in the rate parameters were observed between polyisoprene and polybutadiene, between cis- and trans-polyisoprenes, and between 1,4- and 1,2-polybutadienes.
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  • 87
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 2907-2916 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 1,4,5,8-tetrahydro-1,4;5,8-diepoxyanthracene reacts with various anthracene end-capped polyimide oligomers to form Diels-Alder cycloaddition copolymers. The polymers are soluble in common organic solvents, and have molecular weights of approximately 21000 to 32000. Interestingly, these resins exhibit lower weight loss in air than in nitrogen. This is suggested to be due to dehydration (loss of water ranges from 2 to 5%) at temperatures of 390 to 400°C to give thermooxidatively stable pentiptycene units along the polymer backbone. Because of their high softening points and good thermooxidative stability, the polymers have potential as processable, matrix resins for high temperature composite applications.
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  • 88
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 2923-2939 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The concept of thermally reversible crosslinking was investigated by using poly[bis(trifluoroethoxy)phosphazenes] with different percentages of cyclopentadienylethoxy and dicyclopentadienyldiethoxy substituent groups. The resultant structures of these polymers are discussed and the phenomenon of reversible crosslinking is demonstrated by means of a DSC study and solubility behavior.
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  • 89
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 2953-2971 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Dependence of Parylene C deposition rate on dimer sublimation temperature, inert gas pressure, substrate temperature, and mass of dimer has been investigated. It was found that Parylene C deposition proceeds best at ambient temperature and produces film of optimum performance. Opacity in the film results from its rough morphology and not from the incorporation of the dimer in the film as is normally thought. This was evidenced from scanning electron microscopy and from an estimation of the volatile contents of the Parylene C films. Deposition of Parylene C at liquid nitrogen temperature proceeds via trapping of active monomer species followed by spontaneous polymerization. A quantitative study of the monomer to polymer transition by ESR spectroscopy is presented.
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  • 90
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 2973-2989 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetics of propylene polymerization by superactive CH-catalyst prepared from toluene solution of MgCl2 · EH/PA/TiCl4-TEA/PES was investigated. The results are compared with CW-catalyst prepared from crystalline MgCl2/EB/PC/TEA/TiCl4-TEA/MPT (abbreviations given in the text). The former is four times more active than the latter and produces more isotactic polypropylene. The CH-catalyst has 25% of the Ti as isospecific sites as compared to 6.7% for the CW-catalysts. These sites have the same rate constant of propagation so that the higher polymerization activity of the CH-catalyst is attributable simply to a greater number of active sites. Differences in the kinetics of deactivation and of chain transfer for the two catalysts are described.
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  • 91
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 3015-3029 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A heterocyclic nitrogen-containing system having substituent primary diol function, i.e., 1,1′-dihydroxethyl-2,2′-biimidazole (I), has been prepared and used to synthesize a series of new polyurethanes based on aromatic diisocyanates (TDI, MDI). Variation of solution polymerization parameters permitted the isolation and infrared, NMR, molecular weight, and thermal characterization of polymeric materials. Isolated polymers exhibit a linear structure and have Tg (150-170°C) and thermal stability (205-250°C for 20% weight loss) properties comparable to other typical urethane polymers. Zn2+ complexation was indicated by shifts in the imidazole ringmode infrared vibrational bands at 917 and 1133 cm-1 to higher frequencies.
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  • 92
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 2997-3014 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Phosphonic acid ester derivatives of glycerol, D-mannitol, D-sorbitol, pentaerythritol, and dipentaerythritol have been synthesized by transacetalation reactions with diethyl 2,2-diethoxyethylphosphonate. These phosphonated derivatives of polyols and carbohydrates have been esterified to from the corresponding methacrylates. All these compounds have been characterized on the basis of their elemental analysis and spectroscopic (infrared including FT-IR, 1H-, 13C-, 31P-NMR, and mass) methods. Transacetalation reactions with dialkyl 2,2-dialkoxyethylphosphonate lead to the synthesis of 1,3-dioxane derivatives in the case of D-mannitol, pentaerythritol, and dipentaerythritol, whereas a mixture of both 1,3-dioxane and 1,3-dioxolane derivatives is obtained with D-sorbitol and glycerol. The methacrylates of phosphonylated polyol derivatives show the capacity to dissolve and interact with metal salts such as bismuth bromide and uranyl nitrate. Some of the polymers obtained from these monomers have been characterized on the basis of their spectral and thermal (differential scanning calorimetry) properties.
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  • 93
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 3071-3076 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Copolycondensation of isophthalic (IPA) and terephthalic (TPA) acids, methylhydroquinone (MeHQ), and aromatic diamines with diphenyl chlorophosphate (DPCP) in pyridine were investigated. The resulting copoly(ester-amides) showed optical anisotropy, which was discussed in terms of the ester and amide sequence lengths in the copolymers. The temperature above which the anisotropy was observed varied in the 225 to 300°C range by changing addition time of a mixture of MeHQ and diamines, initial reaction with MeHQ, and the further reaction with diamines.
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  • 94
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 3119-3121 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Tab.
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  • 95
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 3077-3088 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Nondirect-type thermotropic homo- and copolycarbonates which have flexible spacers between mesogens and carbonate linkages (-mesogenic unit-flexible spacer-carbonate link-flexible spacer-) were derived from dihydroxyalkyleneoxy derivatives containing biphenyl, i.e., 4,4′-bis (ω-hydroxyalkyleneoxy)biphenyl (Ia and Ib), as mesogens and the structure-liquid crystallinity relationships were evaluated by thermal analysis and with polarizing microscope.Homopolycarbonates with high molecular weight were prepared from (Ia) and (Ib), and alkylene diphenyl dicarbonates (II) by melt polycondensation. The polymers form mesomorphic phases and exhibit linear decrease of phase-transition temperatures with increment of alkylene spacer lengths without displaying odd-even number fluctuations. They show lower phase-transition temperatures and narrower mesomorphic temperature ranges than analogous direct-type (-mesogenic unit-functional group-flexible spacer-) biphenyl-containing polycarbonates \documentclass{article}\pagestyle{empty}\begin{document}$ \rlap{--} ({\rm OMOC}({\rm O}){\rm O}({\rm CH}_2)_m {\rm OC}({\rm O})\rlap{--})_x $\end{document} and polyesters \documentclass{article}\pagestyle{empty}\begin{document}$ \rlap{--} ({\rm OMOC}({\rm O})({\rm CH}_2)_m {\rm C}({\rm O})\rlap{--})_x $\end{document}, but have wider temperature ranges than nondirect-type (-mesogenic unit-flexible spacer-functional group-flexible spacer-) biphenyl-containing polyesters \documentclass{article}\pagestyle{empty}\begin{document}$ \rlap{--} ({\rm O}({\rm CH}_2)_n {\rm OMO}({\rm CH}_2)_n {\rm OC}({\rm O})({\rm CH}_2)_m {\rm C}({\rm O})\rlap{--})_x $\end{document}. These results indicate that by the incorporation of alkylene segments between mesogens and carbonate linkages the polymers having reasonable phase-transition temperatures and wider mesophasic temperature ranges can be obtained. Copolycarbonates were prepared from mixtures of (Ib) and 1,4-bis(2-hydroxyethyleneoxy)benzene (IV), nonmesogenic moiety, taken in definite molar ratio in feed and (II) (m = 2 and 4). These copolymers except polymers having only nonmesogenic moiety show liquid crystalline mesophases and have wider phase-transition temperature ranges than the homopolymers. Maximum temperature ranges are observed in the copolymers of composition ratio of 1 : 1. Stable mesophases can be obtained over the entire range of compositions, even though the copolymers contain nonmesogenic units in the backbones.
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  • 96
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 3123-3126 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 97
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 3131-3137 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
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  • 98
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    Journal of Polymer Science Part A: Polymer Chemistry 26 (1988), S. 3151-3158 
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The solid-state 1,3,5-trithiane polymerization initiated by UV-irradiation was studied at various irradiation times and various polymerization temperatures. The conversion of monomer to polymer reaches limiting values (at longest) in about 30 min of reaction. The apparent activation energy of this process is somewhat higher than in the chemically initiated polymerization. Generated by UV, active centers, which initiate the polymerization, are stable. On the basis of X-ray diffraction studies it was found that the prepared polythiomethylene has a hexagonal structure and high degree of crystallinity. In the polymer investigated, a new additional crystal phase is formed, which is not stable.
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  • 99
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    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Monofunctional compounds (benzoic acid, heptyl alcohol, and 2-butoxy-ethanol) were used to investigate the kinetics of the esterification and the alcoholysis reactions. Carboxylic acids (benzoic acid) are the only catalysts present in the reaction medium. The factors which influence the kinetics of the esterification reaction were studied: the nature of the carboxylic acid (substituents on the benzene ring), the nature of the alcohol, the composition of the reaction medium (alcohol alone or with another solvent, ester, or water). The results point out for an acyl type (AAC2) mechanism. The alcoholysis reaction needs the presence of carboxylic acid as a catalyst to occur significantly. A similar mechanism is proposed for both reactions: nucleophilic attack by the oxygen atom of the alcohol at the ion pair formed by protonation of the acid (esterification reaction) or by protonation of the ester (alcoholysis).
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 100
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reactions of model molecules were considered to study the kinetics and the mechanism of the esterification and the alcoholysis reactions catalyzed by various metal compounds (Li, Na, K, Zn, Co, Mn, Ti). Ti was found to be the most active catalyst for both reactions and to be acting via a different mechanism (concerted). The possible structure of the active titanium intermediate was investigated by means of 1H- and 13C-NMR spectroscopy, FT-IR spectroscopy, and electroconductivity.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
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