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  • 1
    Electronic Resource
    Electronic Resource
    Miscibility of some methacrylate and acrylate homopolymer blends (1992)
    s.l. : American Chemical Society
    Macromolecules 25 (1992), S. 3170-3173 
    Details
    ISSN: 1520-5835
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ma00038a023
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  • 2
    Electronic Resource
    Electronic Resource
    Cytokine gene expression and release from epithelial cells. A comparison study between healthy nasal mucosa and nasal polyps (1995)
    Oxford, UK : Blackwell Publishing Ltd
    Clinical & experimental allergy 25 (1995), S. 0 
    Details
    ISSN: 1365-2222
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Backgroud Epithelial cells release cytokines and they probably contribute to chronic inflammation detected in bronchial asthma, rhinitis and nasal polyposis.Objectives To investigate the effect of cultures on cytokine gene expression to compare epithelial cell cytokine release by both healthy nasal nucosa (HNM) and nasal polyps (NP), and the modulation by dexamethasone and to investigate which cytokines may promote eosinophil survival.Methods Epithelials cells were cultured to confluence, human epithelial cell conditioned media generated with or without dexamethasone, and supernalanls measured by ELISA. Cytokine gene expression was investigated by reverse transcription-polymerase chain reaction (RT-PCR).Results Fresh epithelial cells only expressed mRNA for intesleukin-8 (IL-8) and granulocyte macrophage-colony stimulating factor (GM-CSF) while cultured cells expressed mRNA for IL-1β IL-6, IL-8, tumour necrosis factor-α (TNFα) and GM-CSF. Epithelial cells from NP significantly (P 〈 0.05) released more IL-8 (25431 ± 3163 pg/mL), and GM-CSF (1229 ± 391 pg/mL) than those from HNM (18604 ± 1723pg/mL for IL-8; and 611 ± 98 pg/mL for GM-CSF), Dexamethasone 10 μM inhibited the release of all cytokines, this effect being similar (40 50%) in both HNM and NP. except for IL-6 which was higher in HNM. Eosinophil survival induced by epithelial cell secretions from both HNM and NP was strongly blocked by GM-CSF antibody while it was partially blocked by antibodies to TNFα and IL-8.Conclusions These findings suggest that although epithelial cell culture procedures may upregulate cytokine gene expression, nasal polyps may represent a more active inflammatory tissue by releasing more cytokines than healthy nasal mucosa this release being inhibited by steroids; and that, in addition to GM-CSF.other cytokines such as TNFo and IL-8, may also be involved in the promotion of eosinophil survival.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2222.1995.tb01108.x
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  • 3
    Electronic Resource
    Electronic Resource
    Thermal stability of poly(methyl methacrylate) as polymerized in aqueous media by using redox systems as initiators (1989)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 27 (1989), S. 3161-3171 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The thermal degradation of poly(methyl methacrylate) as polymerized in aqueous nitric acid solution using Ce(IV) alone and in combination with isobutyl alcohol, isopropyl alcohol, glucose, maltose, and cellobiose as initiator systems has been investigated using differential thermal analysis (DTA) and thermogravimetry (TGA) in dynamic nitrogen. The kinetic parameters E, n, and A have been obtained following several methods of thermogravimetric analysis. The most stable material was found to be the PMMA sample obtained with Ce(IV), and the Ce(IV)-IBA and Ce(IV)-maltose polymerized samples were the least stable. In the pyrolysis of Ce(IV)-IBA and Ce(IV)-maltose polymerized samples it was found that two reactions occurred, while in the case of the PMMA polymerized with Ce(IV), Ce(IV)-IPA, Ce(IV)-glucose, and Ce(IV)-cellobiose three reactions took place.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1989.080270920
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  • 4
    Electronic Resource
    Electronic Resource
    Thermal stability of copolymers of vinyl acetate and methyl acrylate (1989)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 27 (1989), S. 3173-3183 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The thermal degradation of a series of copolymers of vinyl acetate and methyl acrylate and the two homopolymers poly(vinyl acetate) and poly(methyl acrylate) obtained using Ce(IV) as initiator has been investigated using differential thermal analysis (DTA) and thermogravimetry (TGA) in dynamic nitrogen. The kinetic parameters E, n, and A have been obtained following several methods of thermogravimetric analyses. The stability increases as the methyl acrylate content in the copolymer composition increases. The incorporation of 5 mol % of vinyl acetate in the copolymer produces a marked decrease in stability compared to the homopolymer poly(methyl acrylate). There is evidence for an intramolecular lactonization process in vinyl acetate - methyl acrylate copolymers.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1989.080270921
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  • 5
    Electronic Resource
    Electronic Resource
    Aqueous polymerization of methyl methacrylate initiated by Ce(IV)-alcohol redox systems: Effect of acid concentration and additives (1989)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 27 (1989), S. 2427-2433 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polymerization of methyl methacrylate (MMA) initiated by ceric ammonium nitrate in combination with alcohols, isopropyl and, isobutyl alcohol, has been studied in aqueous nitric acid. The effect of nitric acid and nitrate ion concentrations on the initial rate of polymerization as well as on that of ceric ion consumption and on polymer molecular weight has been investigated. The rate of polymerization initially rapidly to a maximum with increasing nitric acid concentration at constant nitrate ion concentration, and then, decreased at higher acid concentrations. The rate of ceric ion consumption increased on increasing the acid concentration. A fall in both the rates was observed as the nitrate ion concentration increased, and when acid concentration was kept constant. Average-molecular weights decreased with increasing the acid concentration; whereas they increased with increasing that of nitrate ion. The effect of certain water-miscible organic solvents has also been studied. Both the rates increased in their presence, whereas the molecular weight underwent a decrease
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1989.080270723
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  • 6
    Electronic Resource
    Electronic Resource
    Aqueous polymerization of methyl methacrylate initiated by the redox system Ce(IV)-isopropyl alcohol. Kinetics and molecular weight (1989)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 27 (1989), S. 3703-3720 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Polymerization of methyl methacrylate was carried out in aqueous nitric acid in the temperature range 26-40°C, with the redox initiator system ceric ammonium nitrate-isopropyl alcohol. A short induction period was observed, as well as the attainment of a limiting conversion, and the total ceric ion consumption with reaction time. The reaction orders were 1/2 and 3/2 with respect to the IPA and monomer concentration, respectively, within the range (3-5) × 10-3M of Ce(IV). But at lower Ce(IV) concentration (≤ 1 × 10-3M), the order with respect to monomer and Ce(IV) changed to 1 and 1/2, respectively. The rate of ceric ion disappearance was first order with respect to Ce(IV) concentration and (RCe)-1 was proportional to [IPA]-1. Both the rate of polymerization and the rate of ceric ion consumption increase with rise in temperature. The average-molecular weight can be controlled by variations in IPA, Ce(IV), and monomer concentrations, and in temperature. A kinetic scheme involving oxidation of IPA by Ce(IV) via complex formation, whose decomposition gives rise to a primary radical, initiation, propagation, and termination of the polymeric radicals by bimolecular interaction is proposed. An oxidative termination of primary radicals by Ce(IV) is also included.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1989.080271112
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  • 7
    Electronic Resource
    Electronic Resource
    Study of the morphology of poly(methyl methacrylate) as polymerized by the redox system Ce(IV)-isopropyl alcohol (1989)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 27 (1989), S. 3439-3450 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Methyl methacrylate has been polymerized in aqueous nitric acid at 30°C, with the redox system ceric ammonium nitrate-isopropyl alcohol as initiator. The gravimetric method has been used to follow the reaction. After a short induction period polymerization started, and conversion attained a maximum value with extent of reaction, whereas the ceric ion is exhausted. The size, distribution, and number of PMMA particles formed were measured by scanning electron microscope. From the electron micrographs it was found that the particles are formed over a short period, and that the particle size distribution seems to be determined by flocculation and coagulation of the particles, because these are not stabilized. Average-molecular weight was found to increase at high conversions and the molecular weight distribution became broader as particle size increased. Particle size increased with conversion, whereas the number of particles remained constant.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1989.080271022
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  • 8
    Electronic Resource
    Electronic Resource
    Thermal behavior of cellulosic graft copolymers. II. Cotton grafted with binary mixtures of vinyl acetate and methyl acrylate (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 39 (1990), S. 1101-1119 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Thermal degradation of cotton, mercerized cotton, cotton grafted with vinyl acetate-methyl acrylate mixtures at different compositions, and mercerized cotton grafted with vinyl acetate-methyl acrylate mixture at a composition of 60 : 40 has been investigated using the techniques of thermogravimetric analysis (TGA) and differential thermal analysis (DTA) in nitrogen. The kinetic parameters E, n, and A have been obtained following several methods of thermogravimetric analyses. The mercerization shows a little effect upon thermic properties of cotton cellulose, making cotton thermally more stable. Graft copolymerization of vinyl acetate-methyl acrylate mixture makes cotton thermally less stable if the composition of the copolymer grafted is 100, 90, and 70 mol % VA, while in the case of cellulose graft copolymers with compositions of VA-MA of 80 : 20, 20 : 80, 5 : 95, and 0 : 100 the thermal stability is higher than that of original cotton. The thermal stability of the mercerized cotton grafted with vinyl acetate-methyl acrylate mixture with a composition of 60 : 40 depends on the percent grafting yield. The thermal stability of mercerized cotton grafted with the monomer mixture is higher than that of cotton grafted with that monomer mixture. The degradation of cellulose and cellulose graft copolymers is complex as is shown by DTA thermograms and kinetic parameters.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1990.070390507
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  • 9
    Electronic Resource
    Electronic Resource
    Thermal behavior of cellulosic graft copolymers. I. Cotton grafted with vinyl acetate and methyl acrylate (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 39 (1990), S. 2219-2235 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The thermal degradation of samples of cotton, cotton oxidized by ceric ion, cotton grafted with vinyl acetate and methyl acrylate having different percent grafting yield, poly(vinyl acetate), and poly(methyl acrylate) has been investigated using the techniques of thermogravimetric analysis (TGA) and differential thermal analysis (DTA) in nitrogen. The kinetic parameters E, n, and A have been obtained following several methods of thermogravimetric analyses. The ceric ion redox system shows little effect upon thermic properties of cotton cellulose. Graft copolymerization of vinyl acetate makes cotton thermally less stable, while, in the case of methyl acrylate grafted cotton samples having 33, 83, and 174% grafting yield, the initial decomposition starts at lower temperatures; but decomposition beyond 360°C takes place at higher temperatures than those for ungrafted cotton, and in the case of the sample with 430% grafting yield the thermal stability is higher than that of original cotton. The thermal stability of cotton grafted with methyl acrylate is higher than that of cotton grafted with vinyl acetate. The degradation of cellulose and cellulose graft copolymers is complex as is shown by DTA thermograms and kinetic parameters.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1990.070391103
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  • 10
    Electronic Resource
    Electronic Resource
    Polymerization of methyl methacrylate initiated by the redox system Ce(IV)/isobutyl alcohol (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Letters Edition 23 (1985), S. 79-83 
    Details
    ISSN: 0360-6384
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1985.130230205
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