Library

Notes: Silicic acid esters were prepared by the reaction of the silicic acid in tetrahydrofuran with various alcohols such as such as methanol, ethanol, 2-propanol, 1-butanol, 2-methyl-2-propanol and 1-octanol, using an esterification apparatus designed especially to allow the preparation of silicic acid esters from alcohols with low boiling points or appreciable steric hindrance. With the intent of obtaining a spinnable ester solution by condensation of silicic acid esters, the effects of the degree of esterification (DE) and alkyl group on gel time and spinnability are investigated. An increase in the DE and the size of the alkyl group led to an increase in the gel time of the esters. Esters solutions with a good spinnability were prepared from n-butyl and isopropyl esters with DEs of 40-50%. In addition, the gel permeation chromatography of condensing esters with low DEs showed a rapid increase in molecular weight. The results showed that spinnability depended on DE and the ester's alkyl group. Fibers could be formed with length of about 10-100 cm from ethyl, isopropyl, and n-butyl esters with DEs 40-50% and with length of 10 cm from octyl ester with DE 26%.

Notes: Ruthenium (II) complex-containing polymers were prepared and characterized by absorption and luminescence spectra, luminescence quantum yield, and luminescence lifetime. The polymers are Ru(bpy)2(poly-6-vinyl-2,′2-bipyridine)CI2 (1) and Ru(bpy)2(poly-4-methyl-4′-methyl-4′ -vinyl-2,2′-bipyridine)CI2 (2). The absorption spectra and luminescence spectra of polymers 1 and 2 were substantially the same as that of Ru(bpy)3CI2. The lifetime of polymers 1 and 2 was similar to that of the respective monomer model compounds. The lifetime of polymer 1 was very short (ca. 13 ns) in comparison to Ru(bpy)3CI2 (660 ns), whereas the lifetime of polymer 2 (660 ns) was similar to that of Ru(bpy)3CI2. The temperature-dependency of the lifetime was discussed in terms of Watts' model.

Notes: This paper critically examines the scope and limitations of state-of-the-art chromatographic techniques (GPC, GC, HPLC) for separating and analyzing the composition, molecular weight, and molecular weight distribution of acrylate and styrene based polyether macromonomers. Of the three chromatrographic techniques investigated, HPLC is found to be the most useful technique for macromonomer analysis, being applicable over a wide molecular weight range and having favorable selectivities towards the many macromonomer components. Macromonomer purity, n-mer distribution, and molecular weight can be derived from a single chromatographic run. In addition, conformational information can be obtained.

Notes: Three series of epoxy/acrylic interpenetrating polymer networks were prepared by the simultaneous polymerization of diglycidyl ether of bisphenol A, crosslinked with an aliphatic diamine, diglycidyl ether of bisphenol A dimethacrylate, bisphenol A dimethacrylate, and diethoxy bisphenol A dimethacrylate. Under the conditions provided it is believed that the two networks form simultaneously but independently. Differential scanning calorimetry and dielectric measurements indicate that these polymer networks are miscible because they exhibit a single, sharp glass transition temperature, the values of which, however, are lower than predicted by the law of mixture. This decrease may be due in part to the dilution of one network by the other and to the resulting breakage of intramolecular interactions. It is also due, in part or in whole, to the presence of solvent and/or monomer impurities that act as plasticizers.

Notes: Anhydrous chlorides of Mg, Mn, Y, and selected lanthanides were reacted with tri-n-butylphosphate and finally TiCI4 to prepare ethylene polymerization catalysts. With triethylaluminum as cocatalyst the highest activities were observed with Mg, Nd, and Pr, which correlate with the peak activity for Nd and Pr in diene polymerization catalysts prepared from the lanthanides. At a given hydrogen concentration molecular weights and molecular weight distributions and catalyst activities were similar for these three metals. The high activity for Nd and Pr is surprising because NdCI3 and PrCI3 adopt the UCI3 structure rather than a layer lattice structure common to MgCI2 and TiCI3.

Notes: Thermogravimetric-mass spectrometric (TG/MS) and differential scanning calorimetric (DSC) techniques were used in the characterization of oxidative and nonoxidative degradation reactions of a highly crosslinked divinylbenzene/styrene copolymer. When the copolymer was subjected to a temperature-programmed air environment, four exothermic reactions were detected. The initial small exothermic reaction, starting at ca. 125°C and reaching its maximum at ca. 180°C, was presumed to result from the decomposition of peroxides. The second exothermic reaction, which overlapped with the initial one and peaked at ca. 270°C, was attributed to oxidation with a significant amount of oxygen uptake and liberation of some gaseous products such as CO2, styrene, benzaldehyde, ethylstyrene, and ethylbenzaldehyde. The strongest exothermic reaction took place at ca. 290-380°C and had its peak at ca. 360°C. Associated with this reaction was the generation of many gaseous pyrolysates, as given above. The exothermic reaction continued at a relatively constant rate from ca. 380°C to the maximum temperature of the experiment (500°C) with the release of only one gaseous product (CO2). The initial exothermic reaction can be eliminated by controlled thermal decomposition of peroxides; therefore, a more thermally stable polymer can be obtained. Exothermic reactions, starting at ca. 170°C, were observed. Pyrolytic reactions in an inert gas were also studied.

Notes: The average molecular weights and the molecular weight distributions of polystyrene (PS) in the conjugate incompatible phases of the ternary system of PS and polybutadiene with toluene as solvent were studied at 23°C. Gelpermeation chromatography, with ultraviolet and differential refractive index detectors, was used for analyzing the compositions of the conjugate phases and for obtaining the molecular weight averages of PS in the phases. Both narrow and broad molecular weight distribution (MWD) polymer samples were used. The effect of broad MWD polymers is seen as one of narrowing the shape of the binodal, thus effectively increasing the compatible region. The molecular weight averages of PS in the two conjugate phases do not vary significantly in the case of the narrow MWD PS sample while for broad MWD samples the average molecular weight of PS is found to be higher in the PS-rich phase than in the polybutadiene-rich phase for tie lines closer to the plait point indicating a partitioning or redistribution of the molecular weight species of PS between the incompatible phases.

Notes: In an attempt to compare the relative reactivities of different redox systems in graft copolymerization of vinyl monomers onto cellulose, we studied grafting of ethylacrylate (EA) in aqueous medium by using the well-known redox intiator, ferrous ammonium sulfate-potassium persulfate (FAS-KPS) system, and its reactivity was compared with that of Fenton's reagent (Fe2+ -H2O2) towards grafting of EA onto cellulose. Optimum conditions for affording maximum grafting were evaluated and percent grafting is expressed as functions of different reaction variables. Evidence of grafting was obtained from IR spectroscopic measurements, SEM, and TGA studies of the grafted and ungrafted cellulose. A plausible explanation for the observed reactivity pattern shown by (FAS-KPS) and (FAS-H2O2) redox systems is offered. Fenton's reagent (Fe2+ -H2O2) was found to be several times more reactive than (FAS-KPS) redox system.

Notes: The effect of oil-soluble versus water-soluble free-radical generators in the polymerization of styrene in oil-in-water (O/W) micromulsions were investigated by photon correlation spectroscopy. The microemulsions were formed by styrene, brine, sodium dodecyl sulfate (SDS), and pentanol. The polymerizations were carried out in two microemulsions that contained droplets differing by a factor of 2.4 in volume. Under the conditions of φ = 0.019 and NaCl/SDS 〉 2 the microemulsions were stable and the droplets were independent of one another. Both oil-soluble and water-soluble initiators produced polystyrene that contained fractions of two different sizes. In the case of the oil-soluble initiator the droplet size in the microemulsion seemed to be correlated to the size of the product whereas in the case of the water-soluble initiator, there seemed to be little relation.

Notes: The synthesis, thermal characterization, and oxygen index of aromatic polyamides varying with polymeric unit linkage positions (meta and/or para units) and halogen substitution have been reported. It has been found that polyamides containing para units are more thermal stable than those containing meta units. There is no significant effect of the main chain structure studied here on either the pyrolysis pathways or flammability of similarly halogen substituted polyamides.

Notes: Rutherford backscattering spectrometry (RBS) has been used to detect and quantitate the thallium concentration resulting from the thallous ethoxide derivatization of phenol and carboxylic acid groups contained in the surface region of bisphenol-A polycarbonate (PC) sheet. Hydrolysis of the PC surface prior to derivatization leads to increased thallium levels, in which the chemical nature of the thallium is shown to be of the form R-O-Tl (R = alkyl or aromatic) by electron spectroscopy for chemical analysis (ESCA). Similar trends in thallium concentrations were observed by both RBS and ESCA for PC surfaces that had been exposed for increasing lengths of time to accelerated weathering and outdoor Florida conditions. The detection limit for thallium in PC using RBS is ca. 5 × 1013 atoms/cm2. The diffusion of thallous ethoxide and transesterification of the aromatic carbonate linkage led to a thallium-containing layer 300-700 Å thick, which increased the experimental uncertainty when assaying residual uncapped polymer chains in unweathered material. During the course of the RBS analysis, the interaction of 2-MeV 4He+ with the PC substrate caused dramatic chemical and physical changes. Microscopy and profilometry indicate that a crater was formed having the same cross-sectional area as the incident ion beam with a depth (ca. 0.3-1.5 μ) that varied according to the beam energy and integrated charge. ESCA analysis provided evidence for the loss of the carbonate linkage and the appearance of carbonyl and ester groups. Infrared analysis of the crater bottom shows the appearance of O-H stretch, carbonyl functionality other than aromatic carbonate, and enhanced aromatic ring stretch vibrations. Crosslinking and subsequent densification of the polymer matrix are though to be responsible for the observed morphological changes. It is suggested that this beam-induced damage does not prohibit the use of RBS to measure high-Z elements on a PC matrix since quantitation of 1000-Å Au layers on silicon and PC gave identical results.

Notes: Copolymerization of vinylene carbonate (VCA) with methyl trifluoroacrylate (MTFA) was carried out by gamma rays from 60Co at dose rates of 1 × 105 rad/h to 1 × 106 rad/h, temperatures of 0°C to 75°C, and molar ratios MTFA/VCA of 30/70 to 90/10 in the monomer mixture. By irradiation, VCA reacted with MTFA to give a white powder copolymer with low molecular weight. The copolymerization rate has a maximum at a concentration of 70 mol % VCA, and is proportional to the 0.92 power of dose rate. The apparent activation energy was 1.3 kcal/mol. Equimolar copolymer was obtained at molar ratio MTFA/VCA of 50/50 to 10/90. The reactivity ratios of both monomers, VCA and MTFA, were determined to be r(VCA) = 0.3 and r(MTFA) = 0.07, respectively.

Notes: A detailed investigation was made by ESCA of the gross structural features and chemical composition of ultrathin plasma polymer films prepared from tetrafluoropyridazine. The data reveal evidence of extensive rearrangement that accompanied polymerization and that the C:F and C:N stoichiometries of the polymer films were similar to those of the starting monomer. From an initially high contact angle with water the surfaces became completely wettable with time and this is attributed to surface hydrolysis. A comparison is made between surface and bulk compositions. Brief consideration is also given to sleeve effects.

Notes: Alternating copolymers of phenylvinyl ethyl ether (I) and phenylvinyl sec-butyl ether (II) with maleic anhydride (MAn) were prepared in bulk or in benzene solution by high-energy irradiation at dose rates of 42, 160, and 540 Gy/h, respectively. The overall energies of activation in copolymerization of I and II with MAn were 15.5 and 18.8 kJ/mol, respectively. The reaction proceeds by the free-radical mechanism and was found to be largely dependent on the bulkiness of the alkyl group. In the copolymerization of I and MAn, the molecular weight increases with conversion. By applying the model described by Shirota and co-workers, it was established that participation of charge-transfer-complex monomers increases with the increase of the total monomer concentration and with the bulkiness of the alkyl group in electron donor monomer.

Notes: Cationic polymerization of 1,4,6-trioxaspiro [4,4]-nonane (1) with (CH3)3O+SbF6-(2) and CH3OSO2CF3(3) initiators has been investigated. Although the observed rates of initiation and propagation are relatively slow, they consist of rapid reversible elementary reactions. In 1H-NMR spectra, a broadening of the monomer signal was observed, indicating a fast exchange between “free” monomer and monomer engaged in the active species. The variety of orthoester bonds were observed in the polymer formed at the early stages of monomer conversion. The final polymer has, however, structure of a linear poly(ester-ether) including two subsequent ester or ether linkages. To account for these new facts, the mechanism of polymerization was proposed, consisting of a rapid reversible opening of one of the rings in the monomer molecule involved in the growing species, followed by the slower opening of the second ring with formation of the ester linkages. It appears that the rings originally present in the chains rearrange into the linear units intramolecularly.

Notes: Plasma polymers synthesized by inductively coupled RF techniques have been investigated as a function of operating parameters for the isomeric perfluorinated diazines (pyrazine, pyrimidine, and pyridazine). A combination of ESCA and microanalytical studies shows that plasma polymers are produced by rearrangement mechanisms: the C/F and C/N stoichiometric ratios are similar to those of the starting monomers over a range of operating parameters. A comparison of rates of formation of plasma polymer films reveals distinctive differences between the isomeric diazines that suggest that equilibration of valence isomers occurs on a substantially slower time scale than for isomeric fluorinated benzenes5-9 which, in general, polymerize at essentially the same rates. In contrast to the remarkably low critical surface tension of plasma polymers based on perfluorobenzenes (ca. 20 dynes cm-2), the plasma polymer films from the perfluorinated diazines which are initially hydrophobic become hydrophilic in contact with water droplets. This is attributed to the hydrolytic instability of films associated with the labilizing influence of nitrogen on nucleophilic displacement of fluoride which is a feature of the chemistry of monomers.

Notes: Studies were conducted on grafting of acrylamide (AM) and sodium-2-acrylamido-2-methylpropane sulfonate (NaAMPS) comonomers onto dextran utilizing Ce(IV) induced initiation. The effects of reaction temperature, the Ce(IV)/dextran ratio, and the AM/NaAMPS ratio on grafting yield were investigated. The graft copolymerization behavior can be explained by exchange of the AMPS anion with one of the ligands on the Ce(IV) initiator. Oxidative modification of the dextran substrate improved the yield of graft copolymer. The dextran-g-poly(acrylamido-co-sodium-2-acrylamido-2-methylpropane sulfonate) samples prepared by this method were characterized as to copolymer composition and molecular weight utilizing elemental analysis, dilute solution viscometry, and aqueous size exclusion chromatography. Relationships of molecular weight and charge density to kinematic viscosity and salt sensitivity are discussed.

Notes: The concentration-dependence measured by steady-state permeation and unsteady-state dyeing methods for a system of acid dye C.I.Acid Blue 182-nylon 6 film in the presence of inorganic salts such as NaCl, Na2SO4, and K2SO4, was analyzed in terms of parallel diffusion with simultaneous multimodal adsorption. It would found that the dyeing process with added NaCl was governed by surface diffusion with two kinds of Langmuir adsorption, whereas with added Na2SO4 and K2SO4 it was governed by surface diffusion with three kinds of Langmuir adsorption.

Notes: Laser flash photolysis of diphenyliodonium salts produces phenyliodinium radical cation (PhI+·), which was also generated independently by flash-induced electron transfer from iodobenzene to a phenanthrolinium salt. Apparent second-order rate constants were determined for reaction of the transient (PhI+·) with nucleophiles, including iodobenzene and cyclohexene oxide. Quantum yields of formation of acid from stationary photolysis of diphenyliodonium hexafluoroarsenate were found to be significantly higher than yields of iodobenzene. These results may be explained by facile reaction of PhI+· with PhI to yield a new iodonium salt together with a proton. High reactivity of PhI+· with cyclohexene oxide suggests that the transient may directly initiate cationic polymerization of epoxides.

Notes: Photoinitiated cationic polymerization by photosensitization of diphenyliodonium and triphenylsulfonium salts is shown to proceed by two distinct electron transfer process: (1) direct electron transfer from excited-state photosensitizers and (2) indirect electron transfer from photogenerated radicals. The efficiency of the former process is attributed to the instability of the reduction products (from diphenyliodonium and triphenylsulfonium salts), which dissociate in competition with undergoing energy-wastage reverse electron transfer. Amplification of photons in the production of protons (or other reactive cations) is postulated to account for the high quantum yields observed in the latter process. Potential advantages of utilizing the indirect redox process in the design of UV curable hybrid systems, which contain functionality for both radical and cationic polymerization, are noted. The results also provide evidence against the importance of triplet states of the onium salts in photoinitiator activity.

Notes: The effect of solvent in homo- and copolymerizations of methacryloyl fluoride (MAF) was investigated in various aromatic solvents. In these solvents, there is a significant effect on the rate of polymerization, on the tacticity of the resulting poly(methacryloyl fluoride), and on the copolymerization of MAF with methyl methacrylate (MMA). The equilibrium constants between MAF and aromatic solvents were determined from NMR spectroscopic measurements. These results indicated that the solvent effect on the MAF polymerization stems from changes in reactivity of MAF induced by the strong MAF-solvent interaction as well as stabilization of the MAF radical by solvents. Copolymerization of MAF with both p-methoxystyrene (MSt) and p-nitrostyrene (NSt) was also studied.

Notes: The thermodynamical properties of the star-branched polymers on the tetrahedral lattice are studied taking into account nearest-neighbor interactions. The excess free energy and energy and heat capacities are computed for wide ranges of chain lengths, reduced potential ∊/kT, and number of branches. A significant influence of the degree of branching on long-range interactions in the polymer random coil is observed. The possibilities of phase transitions in both linear and branched systems are discussed on the basis of the Monte Carlo data.

Notes: Racemic and optically active N-carboxyanhydrides (NCA)s of 2-methyl- and cis-6-methylpipecolic acid, when subjected to polymerization conditions in solution or in bulk whether with “weak” or “strong” base initiators, resisted polymerization under all conditions tried. Instead, the NCA of 2-methylpipecolic acid gave the corresponding cyclic dipeptide and the NCA of cis-6-methylpipecolic acid formed the cyclic dipeptide derived from trans-6-methylpipecolic acid. The mechanism of dimerization of these NCA's was investigated. Evidence was provided for the proposed mechanism in which the active moiety is not a carbamate ion but an amino group. Methyl 2-methylpipecolate underwent an intermolecular SN2-type reaction upon heating, yielding equimolar quantities of methyl N-methyl-2-methylpipecolate and 2-methylpipecolic acid.

Notes: Photomicrographys of concentrated lyotropic hydroxypropylcellulose solutions confirm the cholesteric nature of the anisotropic phases in acetic acid and water. They reveal the existence of biphasic separation. Typical liquid-crystal solvent-dependent textures are observed. The behavior of liquid-crystalline phases in mixed solvents is also studied, and the cholesteric pitch of the twist structure is measured for various relative concentrations of solvents. Spherical droplets, or “spherulites,” in well-defined relative concentrations of solvents have been observed.

Notes: The chlorometylation of linear and crosslinked polystyrene with 1,4-bis(chloromethoxy) butane was studied, and the behavior of 1,4-bis(chloromethoxy)butane in the presence of chloromethylation catalysts was also established by 1H-NMR spectroscopy.

Notes: High-molecular-weight branched-addition polymers made from oligomeric solid epoxy resins and amines carrying two active hydrogen atoms are described. The reaction with aliphatic amines like ethanolamine, 2-ethylhexylamine, or piperazine can easily be controlled carrying out the polymerization in about 15% solutions of boiling 2-methoxyethanol. Less basic derivatives of aniline and epoxy resins are processed at 200°C in the molten state. Polymers with Mn up to 33,000 and Mw to 720,000 are obtained. Properties of films and injection moldings are described. The tertiary nitrogen atoms present in the polymer chain can be quaternized with alkylating agents, like dimethylsulfate, methyliodide, or trimethyl phosphate. Thin membranes cast from the polyquats thus obtained exhibit a good flow rate for water and a high salt rejection under reverse osmosis conditions.

Notes: The ignition of slabs of high-impact polystyrene by a lean hydrogen-oxygen flat flame was studied. The ignition delays and inital rates of flame development after ignition are reported as functions of gas temperature and the separation between flame and polymer surface. The delays follow an Arrhenius-type expression with an activation energy of 98 ± 18 kJ mol-1. The rates of flame development drop as the gas temperature increases. During long ignition delays the apparent heat transfer coefficient at the sample surface dropped from about 100 W m-2 K-1 to values close to that expected for a hot gas impinging at right angles on a cold surface. For short delays it was higher and more constant at about 100 W m-2 K-1. Although the surface temperature reached before ignition exceeded that required for nonoxidative pyrolysis, the polymer surface charred only when oxygen was present. It is concluded that both oxidative and nonoxidative pyrolysis contribute to the ignition of polystyrene.

Notes: A new convenient route to metal containing polymers is described. This method involves emulsion co(ter) polymerization of a polar hydrocarbon soluble monomer, N-isobutoxymethylacrylamide (IBMA), with styrene or styrene/butadiene, followed by addition of metals. Metal incorporation is effected by latex or solution techniques. Preparative, atomic adsorption, spectroscopic, film observation, and dilute solution data are presented in support of metal complexation. Structures for the complexes are proposed.

Notes: Five general routes for the preparation of polyoxyethylene [generally referred to as poly(ethylene glycol) or PEG] derivatives are described. These routes are (1) nucleophilic displacements with the alkoxide of PEG, (2) nucleophilic displacement on PEG-tosylate, -mesylate, or -bromide, (3) reductive amination of PEG-aldehyde, (4) reductive amination of PEG-amine, and (5) nucleophilic displacements on the s-triazine derivatives prepared from s-triazine trichloride (cyanuric chloride) and PEG. Eighteen derivatives are prepared and potential applications to catalysis, cell purifications, and other areas are discussed briefly.

Notes: The size distributions of a number of multifunctional polycondensations which contained mixtures of monomers of different functionalities were derived from kinetic reaction schemes. The distributions obtained were in agreement with those derived by other authors on similar systems. The distribution functions differed, however, from those obtained by a kinetic method by using mean functionalities of the monomer mixtures; the reasons for the differences were explored. Size distribution parameters also obtained were used to consider the differences between actually observed gel points and gel points calculated for multifunctional polycondensing systems.

Notes: Reversible photocolor developments of viologens embedded in poly(N-vinyl-2-pyrrolidone) films, a typical polar aprotic solid matrix, were found to be affected by the kinds of viologen cation as well as the paired anion. The color developments in the corresponding low-molecular-weight solvents are connected closely to the solubility of viologens in these solvents; viologens are highly sensitive in the polar aprotic solvents in which they have poor solubilities, such as N-methyl-2-pyrrolidone and hexamethyl phosphoric triamide. These facts confirm the color-development mechanism consistings of electron transfer to the photoexcited viologen cation from the paired anion in polar aprotic solid matrices such as poly(N-vinyl-2-pyrrolidone).

Notes: The polymerization of 6-amino-2,4-trans,trans-hexadienoic acid and various of its salts was studied in the solid state. Crystals of the hydrochloride and organic inorganic double halides with cadmium chloride, manganese (II) chloride, and iron(II) chloride were found to polymerize rapidly upon UV or γ irradiation. An erythro-diisotactic polymer is obtained in the form of extended chain crystals. The polymer behaves as an amphoteric polyelectrolyte. The kinetics and the mechanism of the polymerization as well as morphological changes during the solid state reaction are discussed.

Notes: The catalytic activities of N-decanoyl-L-histidine and its methyl ester and of dipeptide derivatives containing an L-histidine residue toward the stereoselective hydrolysis of enantiomeric substrates have been studied at pH 7.30 (in 0.01M Bis-tris buffer) and 25°C in the presence of poly(ethyleneimine) derivatives. The dipeptide catalyst revealed greatest stereoselectivity in a quaternized poly(ethyleneimine) derivative. A comparison of catalytic effects on both the rate constants and stereoselectivities of N-decanoyl-L-histidine and its methyl ester elucidates the cooperative effects of carboxyl groups in the polymer domains. The structure of the substrates influenced both the rate constants and stereoselectivities in polymer domains.

Notes: Polymerization of methyl methacrylate in visible light was studied at 30°C using the isoquino-line-chlorine charge-transfer complex as the photoinitiator. Analyses of kinetic and other data indicate that the polymerization proceeds via a radical mechanism and the termination is initiator dependent. Chain termination via degradative chain (initiator) transfer appears to be significant.

Notes: ESCA and contact-angle (H2O and CH2I2) measurements are used to follow changes in the surface of poly(ethylene terephthalate) film photooxidized (254 nm radiation in O2) for varying times, followed by aging for as many as three weeks or washing with water. Photooxidation occurs uniformly throughout the outermost 50 Å of the film to give a surface stoichiometry that corresponds to C10O6.6. Oxidation produces mainly carboxyl (acid) and alcohol/phenol groups, carbonyls form after extensive treatment. Low molecular weight products formed by chain scission and oxidation are removed by washing and diffuse into the bulk when aged. Oxidized products in higher molecular weight chains are not removed by washing, but can diffuse into the polymer bulk or reorient because of their chain mobility; therefore they are directed toward the polymer bulk rather than the surface. Extended photooxidation produces a stable oxidized surface more resistant to aging changes. The results are compared with those obtained for poly(ethylene terephthalate) film oxidized in an electrical discharge.

Notes: It has been shown, using the significant structure theory of liquids, that a lower critical solution temperature behavior as well as a upper critical solution temperature behavior can be expected for polymer-polymer systems and that a phase diagram of closed-loop-type in a polymer-polymer-solvent system can be possible. In this article the sublimation energy of a mixture was expressed as a quadratic form of segment surface fractions on pure components rather than that of mole fractions, and the effect of the segment surface fractions on critical compositions was explained. The calculated partial miscibilities were in good agreement with the experiment.

Notes: Vinyl acetate was copolymerized with benzylidenemalononitrile in bulk by radical initiation at 80°C up to low conversions. Alternating copolymers were formed over a wide range of monomer feed ratios. The copolymerization parameters were determined by the conventional scheme. The copolymers were characterized by IR, proton, and 13C spectroscopy and their basic properties, solubility, viscosity, and thermal behavior were determined.

Notes: Alternating and random copolymers of ethyl α-cyanocinnamate and vinyl acetate were studied. Infrared, 1H, and 13C spectra of the copolymers are discussed by comparison with a model compounds, poly(vinyl acetate), and various copolymers. The decomposition temperature and Tg of copolymers of various composition, studied by TMA and DSC, increase both with increasing content of ethyl α-cyanocinnamate.

Notes: Various alkanedithiols [HSRSH; R = (CH2)3-6 or—CH2CH2OCH2CH2—] add to the carbon-carbon double bonds of N,N′-bismaleimido-1,8-octane (1) at room temperature in m-cresol that contains triethylamine as a catalyst to produce the corresponding polyimidosulfides (3) in yields of 75-86% and with inherent viscosities (ηinh) of 0.30-1.05 dL/g. In general (3) are amorphous, elastomeric materials that undergo glass transitions (Tg) within the range of 6.5-13°C but product (3a) [R = (CH2)6] is a tough, leatherlike polymer that exhibits Tg = 35°C and a melting transition at 77°C. X-ray analysis indicates that (3a) is ca. 37% crystalline. In addition to further details of the synthesis and properties of polyimidosulfides (3), comparisons are made between crystalline (3a) and a structurally analogous but morphologically dissimilar, elastomeric polyaspartimide synthesized earlierJ. E. White, M. D. Scaia, and D. A. Snider, J. Appl. Polym. Sci., in press. from (1) and N,N′-dimethyl-1,6-hexanediamine.

Notes: The preparation of flavin-containing, water-soluble terpolymers with varying contents of quaternary ammonium and neutral monomer units is described. The composition of the polymer, that is, the polarity of the polymer chain, affects the UV/VIS absorbance spectrum of the bound flavin moiety by influencing the flavin-solvent interaction. Aerobic oxidation of 1-benzyl-1,4-dihydronicotinamide (BNAH) is accelerated as much as 17-fold by polymer-bound flavins, compared with free flavin. Depending on the ratio of polar/nonpolar groups in the flavin polymer and the 2-propanol content of the aqueous reaction medium (pseudo) first-order or Michaelis-Menten type kinetics were observed as a function of substrate concentration. The influence of the polymer composition on flavin/BNAH complex formation (Km-1) and rate-limiting hydride transfer step (k2) is discussed. Accumulation of the substrate in the polymer domain due to apolar interactions is one of the major factors that determine the observed rate enhancements.

Notes: Poly(styrene-co-4-thiocyanatoacetylstyrene) and poly(4-acetylstyrene-co-4-thiocyanatoacetyl-styrene) were prepared and their photochemical reactions were studied in the solid state. It was found that the thiocyanatoacetyl groups were easily rearranged with the corresponding isothiocyanatoacetyl groups by ultraviolet (UV) irradiation and that the resulting isothiocyanatoacetyl groups underwent intramolecular cyclization when treated with triethylamine or ammonia to yield oxazole-2-thione moieties. The irradiated polymer films could be dyed selectively with cationic dyes in an appropriate dye bath because of the formation of anionic species by keto-enol tautomerization of oxazole-2-thione moieties in an alkaline state.

Notes: Free-radical copolymerization of methyl methacrylate and methyl α-benzylacrylate has been studied in benzene solutions at 40 and 60°C. A simple copolymerization model fits the composition data at both temperatures. However, considering that the ceiling temperature for the polymerization of methyl α-benzylacrylate in benzene solution (|M| = 5 mol/L) is 67°C and that the overall rate of copolymerization drastically decreases with respect to that of methyl methacrylate homopolymerization with an increase of the molar fraction of methyl α-benzylacrylate in the feed, the behavior of this system is analyzed from both simple and reversible copolymerization models.

Notes: Poly-6-(acryloyloxymethyl)uracil was prepared by radical-catalyzed polymerization of monomeric 6-(acryloyloxymethyl)uracil. The reaction of 6-chloromethyluracil with the potassium salt of polyacrylic acids of molecular weights 5000 and 90,000 gave polymers with both carboxylate groups and 50-70% pendant uraciles. Some inferences concerning the arrangement of uracil groups are drawn from the nuclear magnetic resonance (NMR) spectra of the latter polymers. No interaction between poly(A) and the synthetic polymers could be observed.

Notes: Based on a redox function of 1,2-dithiolane ⇌ 1,3-dithiol, lipoamide immobilized on hydrophilic polymers such as polyacrylamide, polyethyleneimine, and chitosan was found to work as polymeric reducing catalysts for the reduction of O-benzylhydroxylamine to benzyl alcohol and ammonia with sodium borohydride in the presence of ferrous ion. These polymers were easily separable and maintained high reactivities even after repeated uses.

Notes: Various phosphorus-containing polyimides were prepared by the reaction of 1-[(dialkoxyphosphinyl)methyl]-2,4- and -2,6-diaminobenzenes (1) with a tetracarboxylic dianhydride like pyromellitic dianhydride (PMDA) and benzophenone tetracarboxylic dianhydride (BTDA). In addition, copolyimides that contained approximately 3% phosphorus were prepared by the reaction of 1 and m-phenylenediamine (MPD) with the aforementioned tetracarboxylic dianhydrides. Elemental analysis, inherent viscosity, infrared (IR) spectroscopy, differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA) studies were performed to characterize the polymers. Their thermal properties were compared with those of the corresponding common polyimides. It was shown that the molecular weight and thermal stability of the polymers were reduced as the concentration of the phosphorus moieties increased. The fire-resistance of the copolyimides was evaluated by determining their limiting oxygen index (LOI) value. Copolyimides that contained about 3% phosphorus showed an LOI value approximately 30% higher, than the value of the corresponding common polyimides. In addition, a model diamic acid and diimide was synthesized by the reaction of 1-[di(2-chloroethoxyphosphinyl)methyl]-2,4- and - 2,6-diaminobenzene (DCEPD) with phthalic anhydride and characterized by elemental analysis, IR, proton nuclear magnetic (1H-NMR) spectroscopy, DSC, and TGA. The pyrolysis behavior of the model compounds was investigated by gas chromatography-mass spectrometry (GC-MS). A direct cleavage of the P—C bond and a possible rearrangement to diisocyanates occurred during their pyrolysis.

Notes: Model p-cresol-formaldehyde condensates having regular sequences of methylene ether and methylene linkages were prepared by the self-condensation of dimethylol derivatives of p-cresol-formaldehyde condensates (2-hydroxy-5-methyl-1,3-benzenedimethanol, 3,3′-methylene-bis[2-hydroxy-5-methylbenzenemethanol] and 3,3′-[(2-hydroxy-5-methyl-m-phenylene)dimethylene]-bis[2-hydroxy-5-methylbenzenemethanol]). 300-MHz 1H-NMR spectra of these polymers and of their acylated derivatives were recorded and used to develop resonance assignments for the various types of protons present in these polymers. The spectra were found to be sensitive to end-group and sequence distribution effects.

Notes: The anionic polymerization of norbornene trisulfide initiated with sodium thiophenoxide (sodium cation solvated with dibenzo-18-crown-6 ether) was studied. Polymers with high molecular weights were obtained (Mn up to 105, osmometrically). Molecular weights calculated for living polymerization conditions (i.e., one molecule of initiator yields one macromolecule) agree well with Mn measured by osmometry. 1H-NMR, 13C-{1H}-NMR, and Raman spectra of the polymer are given. Thermodynamics of polymerization in toluene solvent is described. Enthalpy ΔHss = -(1.39 ± 0.17) kcal mol-1 and entropy ΔSss = -(7.52 ± 0.55) cal mol-1 deg-1 coefficients of polymerization were evaluated from the temperature dependence of the equilibrium monomer concentration determined dilatometrically.

Notes: Poly(methyl vinyl ether-alt-ammonium maleamate), when heated at up to 100°C while removing volatiles, is converted to polymer whose infrared, elemental analysis and Tg are consistent with a structure predominantly that of poly(methyl vinyl ether-alt-maleic anhydride). Maleimide comonomer units are a substantially lesser component. Evidence is presented that a part of the reaction sequence may involve hydrolysis of imide or amide.

Notes: Thin film coatings were prepared by polymerizing trifluoromethyl-substituted aromatic compounds in a glow discharge with low power levels and medium pressures. Smooth, continuous films which are adherent and insoluble in conventional solvents were produced. A significant amount of the fluorine content from the monomer was retained in the polymer. The trifluoromethyl group was not removed by the plasma conditions and appeared in the film as trifluoromethyl and difluoromethylene groups. The films were slightly less wettable than those of the unfluorinated films.

Notes: A fire- and heat-resistant polymer was obtained by the thermal polymerization of bismaleimido-substituted 2,2-bis(anilino)-4,4,6,6-tetrakis-(4-Aminophenoxy)-cyclotriphosphazene. The thermal stabilities of the polymer were evaluated in nitrogen and in air by thermogravimetric analysis. This polymer was stable to 345°C and had char yields of 78% at 800°C in nitrogen and of 71% at 700°C in air. The structures of cyclotriphosphazene precursors and the polymer were characterized using Fourier-transform infrared and proton nuclear magnetic resonance spectroscopy.

Notes: In a new, one-step synthesis, polyglycolide was prepared by the reaction of bromo- or chloroacetic acid with triethylamine in a nitromethane solution. It was discolored, by iodoacetic acid possibly as a result of iodine formed by the decomposition of triethylammonium iodide. The structure of polyglycolide was characterized by hydrolysis, 1H-NMR and IR spectra, and x-ray powder diffraction, which indicated partial crystallinity. A mechanism is proposed for the formation of polyglycolide. A lower limiting value of the number-average molecular weight of 104 was determined by cryoscopy in 1,3-dinitrobenzene for polyglycolide prepared from bromoacetic acid; the measurement was inaccurate because of the low solubility of the polymer. No significant effect of solvent (acetone, ether, or chloroform) on yield or melting point was observed; a higher yield was obtained in nitromethane. The polymer obtained with tri-n-propylamine and bromoacetic acid had properties similar to that obtained with triethylamine. No polymer was obtained with N,N-dimethylaniline and bromoacetic acid or with triethylamine and bromoacetic acid in aqueous solution.

Notes: In the presence of one equivalent of acid, m-phenylenediamine and 2-methyl m-phenylenediamine react with pyridine-3 aldehyde with C alkylation to produce linear polymers, poly(4,6-R-methylene m-phenylenediamine) and poly(4,6-R-methylene 2-methyl m-phenylenediamine). These were characterized by UV, IR, and NMR spectroscopy. Comparison with model compounds confirmed the above structures. A secondary reaction noted at 25°C and higher for the polymer was the oxidative coupling of two neighboring aromatic diamines to produce substituted 2,7-diamino acridine groups along the chain.

Notes: The photochemical polymerization reactions of isoprene with the use of H2O2 as the photoinitiator have been studied in benzene, acetone, and tetrahydrofuran solutions. Hydrogen peroxide is photodecomposed to form hydroxyl radicals which may initiate the polymerization of isoprene with hydroxyl terminated polyisoprene as the product. Average molecular weight, microstructure, and the functionality of the hydroxyl terminated polyisoprene are determined. A suitable reaction mechanism and the polymerization rate equations are proposed. The overall activations energy is evaluated to be about 3.8 kcal/mol.

Notes: The progressive dissolution of carboxylated latex particles with increasing pH was utilized to investigate the internal structure of core-shell latex particles, in comparison with that of copolymeric latex particles formed from the same monomers. The results indicated that in those latex particles which are formed when ethyl acrylate (EA) -methacrylic acid (MAA) or methyl acrylate (MA) -MAA mixture is polymerized in the presence of poly(MA-MAA) or poly(EA-MAA) seeds the shell is composed of the more hydrophilic poly(MA-MAA) molecules relatively high in MAA content and the core is composed of both poly(MA-MAA) and poly(EA-MAA) molecules, regardless of the order of the stage feed, while the copolymeric latex particles are relatively uniform from surface to center in distribution of all components except MAA. Examination of the distribution of the carboxylic groups in all of the latex particles showed their concentration to be highest at the surface and to decrease with proximity to the center in accordance with other findings reported in the literature.

Notes: p-Vinylphenylsulfonylmethyl isocyanide (1M) was synthesized starting with sodium p-styrenesulfinate via p-vinylphenylsulfonylmethylformamide (4M). Free-radical polymerization of 1M provided cross-linked insoluble polymers (1), whereas 4M provided soluble polymers, which could be converted to soluble polymer 1. Conversions of carbonyl compounds to nitriles and Schiff bases to 1,5-disubstituted imidazoles with both soluble and cross-linked polymers 1 as reagents proceeded almost as efficiently as with their low molecular weight analog. Reusability of polymer 1 was fairly good.

Notes: The emulsion polymerization of styrene initiated by potassium persulfate catalyzed by Ti+3 ions was studied. Two sources of Ti+3 ions were used: the titanium trichloride and titanium sulfate. It was found that the titanium ions used in conjunction with potassium persulfate decrease both the reaction rate and the average molecular weight. An even greater drop of reaction rate was noted when chlorine anions (TiCl3) were present. The presence of these ions had a stabilizing effect on the polydispersity.

Notes: Mass spectroscopy was done at different temperatures on epoxylated novolac resin DEN 438 (Dow Chemical Co.) alone, and after curing with various metal(II) phthalocyanine tetraamines (MPTA). Possible modes of fragmentation are given to explain the experimental results. Gas-chromatographic/mass-spectroscopic (GC-MS) analyses of MPTA derivatives indicated the presence of only trace quantities of benzene, aniline, cyanobenzene, and orthodicyanobenzene. The GC-MS studies of the cured DEN 438 epoxy resins indicated that the mechanisms of thermal degradation are qualitatively similar, and some common features were observed in their fragmentation in an electron beam and by thermal degradation. This study is a further assessment of the utility of these phthalocyanine derivatives for curing epoxy resins to produce heat-resistant polymer systems.

Notes: Poly(α-methylstyrene-butadiene-α-methylstyrene) (mSBmS) was synthesized by two stages living anionic polymerization. Sodium naphthalene was used as initiator and HMPT as promoter to accelerate cross-over reactions. The microstructure and composition of mSBmS were identified by infrared and nuclear magnetic resonance spectroscopes. The domain size was roughly calculated from TEM observation. It was observed that the morphology changed with the composition. The mSBmS exhibited two Tgs, -4 and 172°C, that associated with polybutadiene and poly-α-methylstyrene, respectively. Comparing stress relaxation behaviors of mSBmS and styrene-butadienestyrene (SBS) at various temperatures, mSBmS showed a better thermal stability and degradation resistance than SBS. From the thermal gravimetric analysis, at 200°C, mSBmS gave a weight loss less than 1%, which provided a further evidence of better thermal stability of this material than of SBS.

Notes: The cationic grafting of polystyrene initiated by carbon black containing the CO+ClO-4 group was investigated. The introduction of CO+ClO-4 groups onto a carbon black surface was achieved by the reaction of AgClO4 with carbon black that contained a COCI group. The latter was introduced by the reaction of carboxyl groups with SOCl2. It was found that polystyrene chains could be grown from CO+ClO-4 groups on the surface of carbon black. Moreover, polystyrene was effectively grafted from carbon black: the grafting ratio at 20°C increased to 58% as conversion increased. Furthermore, the grafting ratio and molecular weight of ungrafted polystyrene decreased with an increase in polymerization temperature. These results were explained by the fact that the increasing temperature of the polymerization caused an increase in the rate of chain transfer reaction of the growing polymer chain to the monomer. The carbon black obtained from the reaction produced a stable colloidal dispersion in a good solvent for polystyrene.

Notes: Copolymerization studies of methacrylate-terminated polystyrene macromonomers (M1) with several comonomers (M2) verified the modified kinetic scheme and permitted prediction of graft polymer compositions and structures. Instantaneous and cumulative copolymer compositions, average graft distributions, and grafts per molecule are predicted from FORTRAN IV or BASIC programs. The r2 relative reactivity ratios determined from styrene copolymerization (0.61) or from low conversion acrylic monomer in aqueous suspension (∼0.4) had good agreement with literature values (about 0.6 and 0.4, respectively). Decreased macromonomer reactivity determined at high acrylic monomer conversions was attributed to phase separation phenomena. The Macromers also exhibited lower reactivity than predicted when copolymerized with acrylic monomers in DMSO/benzene solutions (r2 ∼ 0.8).

Notes: A Vilsmeier adduct derived from arylsulfonyl chlorides and DMF in pyridine was successfully used as a new condensating agent for the synthesis of aromatic polyesters by the direct polycondensation of aromatic dicarboxylic acids and bisphenols and also of hydroxybenzoic acids. Polymers of high molecular weights (M̄w = 78,000) with relatively narrow molecular weight distribution (M̄w/M̄n ≈ 3.0) were prepared by reacting aromatic dicarboxylic acids with the adduct in pyridine, followed by addition of bisphenols. The polycondensation was significantly affected by the amount of DMF, the nature of the arylsulfonyl chlorides, the conditions of initial reaction of the acids with the adduct, and the rate of reaction with bisphenols. The process was adaptable to the direct polycondensation of hydroxybenzoic acids, affording polymers of high molecular weight (ηinh = 1.73).

Notes: Cationic oligomerization of bicyclic oxalactam, 8-oxa-6-azabicyclo[3.2.1]octan-7-one [abbreviated as BOL (1)], was carried out at 0-60°C with trifluoromethanesulfonic acid and borontrifluoride etherate as catalysts to obtain the oligomer mixture at high yield. From the structural analysis of the isolated dimer, a N-(2(e)-carbamoyltetrahydropyran-6(e)-yl)-8-oxa-6-azabicyclo[3.2.1]octan-7-one, the oligomerization proceeded through the 5C-6N scission in (1) but not through the 6N-7C (amide group) scission as generally observed in common lactams. This peculiar oligomerization must result from the protonation to the oxamide unit in the BOL molecule.

Notes: Several polyamides of p-phenylenedioxydiacetic acid (PDDA) were synthesized by the low-temperature solution polycondensation techniques. Six different diamines were condensed independently with p-phenylenedioxydiacetyl chloride (PDC) in a mixture of N-methyl pyrolidone (NMP) and hexamethyl phosphoramide (HMPA). The polymers were obtained in 80-95% yield and possessed inherent viscosities in the range 0.32-0.81 dL/g. The polymers were characterized by infrared (IR) and H1-NMR spectra. The solubility, density, crystallinity, and thermal stability of the polyamides were also determined. A model diamide (MDA-1) was also synthesized from aniline and PDC to confirm the formation of polyamides from diamines.

Notes: A novel class of fire- and heat-resistant bisimide resins was prepared by thermal polymerization of maleimido or citraconimido derivatives of 1-[(dialkoxyphosphinyl)methyl]-2,4- and -2,6-diaminobenzenes (1). The neat bisimide resin prepared by curing 1-[di(2-chloroethoxyphosphinyl)methyl]-2,4- and -2,6-bismaleimidobenzene exhibited a limiting oxygen index 75% higher and smoke evolution about 30 times lower compared with the parent polymer obtained by curing m-phenylenebismaleimide. The char yield of cured bisimide resins at 700°C was 58-70% in a nitrogen atmosphere and 35-60% in air. An increase in formula weight between the imide groups slightly reduced the char yield. The polymer precursors were synthesized by reacting the phosphorus-containing diamines (1) (1 mol) with maleic anhydride/citraconic anhydride (2 mol) or by reacting the monomaleimido derivative of (1) with benzophenone tetracarboxylic dianhydride/methylenebis(4-phenylisocyanate) in a 2:1 mole ratio. The monomers were characterized by elemental analysis, Fourier-transform-infrared (FT-IR), proton nuclear magnetic resonance (1H-NMR) spectroscopy, and gas chromatography-mass spectroscopy (GC-MS). Direct cleavage of the P—C bond and inversion of the synthesis reaction may occur during their pyrolysis. The thermal polymerization of the monomers was investigated by differential scanning calorimetry (DSC). Biscitraconimides are thermally polymerized at a relatively lower temperature than the corresponding bismaleimides.

Notes: The placement of ionic groups within the molecular structure of a polymer produces marked modification in physical properties. A large number of studies have been performed on these ion-containing polymers, but few have focused on the effects of anion-cation interactions (i.e., counterion binding or ionization) on hydrodynamic volume, especially as the molecular structure of the solvent and nature of counterion are varied. In this study changes in hydrodynamic volume are followed through reduced viscosity measurements as a function of the abovementioned molecular parameters.The dilute solution properties of various polyelectrolytes that contain sulfonate and carboxylate groups were investigated as a function of the counterion structure, charge density, molecular weight, and solvent structure. The polymeric materials were selected because of their specific chemical structure and physical properties. In the first instance a (2-acrylamide-2 methylpropanesulfonic acid)-acrylamide-sodium vinyl sulfonate terpolymer was synthesized and subsequently neutralized with a series of bases. Viscometric measurements on these materials indicate that the nature of the cation affects the ability of the polyelectrolyte to expand its hydrodynamic volume at low polymer levels. The magnitude of the molecular expansion is shown to be due in part to the ability of the counterion to dissociate from the backbone chain, which, in turn, is directly related to the solvent structure. The changes in solution behaviour of these inomers lend support for the existence of ion pairs (i.e., site binding) and ionized moieties on the polymer chains. Measurements performed in a variety of solvent systems further confirm this interpretation. In addition, and acrylamide-sodium vinyl sulfonate copolymer was partially hydrolyzed with sodium hydroxide to study the effect of varying the charge density at a constant degree of polymerization and counterion structure. The results show that the charge density has a significant effect on the magnitude of the reduced viscosity and dilute solution behaviour. These observations, made in aqueous and nonaqueous solvents, are related to the interrelation of hydrodynamic volume, counterion concentration, and site binding. Again the controlling factor is the degree of site binding of the counterion onto the polymer backbone. Finally, we observe that the increased hydrodynamic volume affects viscosity behavior beyond the polyelectrolyte effect regime. If the average charge density on the macromolecule is relative high and/or the molecular weight is large (≥ 106) sufficient intermolecular interactions will occur to produce rapid changes in reduced viscosity.

Notes: Efforts to prepare triphenylsulfonium hexafluorophosphate by metathesis between commercially available “triphenylsulfonium chloride” and potassium hexafluorophosphate failed to yield the expected product but gave, instead, in approximately 50% yield, a crystalline substance with well-defined properties readily distinguishable from triphenylsulfonium hexafluorophosphate. The unexpected substance is identified as bis-[4(diphenylsulfonio)phenyl]sulfide-bis-hexafluorophosphate, for which no previous reference has been found in the literature. Its identification is based on elemental analysis, NMR, mass spectrometry, and infrared analysis. Bis-[4-(diphenylsulfonio)phenyl]sulfide-bis-hexafluorophosphate was also prepared by the reaction of benzene with sulfur monochloride in the presence of aluminum chloride and chlorine, followed by addition of potassium hexafluorophosphate. The product is an effective photonitiator for the crosslinking of epoxide resins.

Notes: The radiation degradation of viscoelastic solutions of a dialkyl monohydroxy aluminum polymer compound (AIR2OH)x is investigated. Radioactive cobalt-60 is chosen for irradiation experiments. The viscosity of the polymer in six different solvents is measured after irradiation using a capillary viscometer at room temperature (25°C). The degradation effects on both the radiation dose and the solvent used.

Notes: The kinetics of aqueous polymerization of acrylamide with KMnO4/glycine redox pair was studied in an atmosphere of nitrogen at 35 ± 0.2°C. The rate of polymerization was found to be first power on monomer, activator, and catalyst concentration. The overall energy of activation was calculated to be 15.66 kcal/deg mol (65.54 kJ/mol) between 30 and 50°C. The effects of various additives (alcohols, neutral salts, complexing agents, addition of catalyst) were studied. The dependence of the polymerization rate on the activator and catalyst concentration was studied in DMF-water mixture also. The molecular weight of polymer was determined at various temperatures of the reaction medium.

Notes: Glycidyl methacrylate was copolymerized with tert-butyl acrylate in bulk at 60°C using benzoyl peroxide as free radical initiator. The copolymer composition was determined by chemical analysis as well as from 13C-NMR data. The monomer reactivity ratios were calculated by using the YBR method. The number average sequence length of the copolymers was determined from 13C-NMR data and compared with those obtained from reactivity ratios. The intrinsic viscosity of the copolymers was determined in DMF, and thermal stability as well as mechanism of thermal degradation of the copolymers were evaluated.

Notes: Asymmetric selective (or stereoelective) polymerization of racemic 1,2-diphenylethyl methacrylate (DPEMA) with ethylmagnesium bromide (EtMgBr)-(-)-sparteine catalyst was studied in toluene at -78°C. In the polymerization (S) enantiomer was consumed preferentially and the enantiomeric excess of initially polymerized (S) enantiomer was consumed preferentially and the enantiomeric excess of initially polymerized DPEMA was greater than 90%. Optically pure (R) monomer was recovered at about 70% polymer yield. Poly(DPEMA) obtained with EtMgBr-(-)-sparteine complex was highly isotactic. It was found in the polymerization of optically active DPEMA that optical rotation of poly(DPEMA) was dependent on the tacticity and that isotactic and syndiotactic poly(DPEMA)s showed opposite optical rotations. Circular dichroism spectra of the optically active polymers were measured.

Notes: In this article we review the synthesis and morphology and the physical and mechanical properties of two-component interpenetrating polymer networks (IPNs) from polyurethane and epoxy polymers; the corresponding pseudo-IPNs and grafted IPNs are also discussed. A comparison was made of full IPNs, pseudo-IPNs, grafted IPNs, and related homopolymers by examining their mechanical properties, mechanical spectra, and electron microscopy on an investigation of the effects of interpenetration or permanent entanglement in the IPN and related systems. This interpenetration has resulted in improved compatibility between the two polymer systems and has caused a decrease in the degree of phase separation. An observed shift in the dynamic glass transition temperatures (Tgs) of the two components which yielded a single IPN Tg further substantiates our results.

Notes: Heterogeneous polymerization of acrylonitrile initiated by ceric ammonium sulfate-citric acid (C.A.) redox system is reported at 35 ± 0.2°C under nitrogen atmosphere. The rate of monomer disappearance is found to be proportional to [C.A.]0, [Ce4+]0.63, and [Monomer]1.59. The rate of ceric ion disappearance is directly proportional to ceric ion concentration but independent of monomer concentration. The initial rate was independent of [H2SO4]. The molecular weight of polyacrylonitrile increases with increasing monomer concentration and decreasing ceric ion concentration. Activation energy was found to be 27.9 kJ/mol.

Notes: The ylide 4-picolinium, p-chloro phenacylide-initiated thermal polymerization of ethyl methacrylate (EMA) was studied. 4-Picolinium p-chloro phenacylide induces the thermal polymerization of ethyl methacrylate at 65°C. The rate of polymerization (Rp) rose as the initiator concentration increased from 2 × 10-3 to 4 × 10-3 M and the initiating exponent was computed as 1.9. The Rp decreased as the concentration of ylide increased from 6 × 10-2 to 1M. The greater initiator concentration also affected the molecular weight inversely. The polymerization was carried out at different temperatures and the overall activation energy was computed as 4.08 Kcal/mol. Polymerization was inhibited in the presence of hydroquinone as a radical scavenger. Kinetic studies and other data show that the overall polymerization takes place in a radical mechanism. The various kinetic parameters, such as the rate and average degree of polymerization, molecular weight, and energy of activation of the present system, were evaluated.

Notes: The kinetics of radical polymerization of methyl methacrylate were investigated in a dioxane solution with cyclohexanone as initiator. It was found that the overall rate of reaction initiated with cyclohexanone (Rp) is proportional to the concentration of monomer and to the square root of the concentration of the initiator. The effect of temperature on the Rp in the temperature range of 65-95°C was discussed. The Arrhenius activation energy Ea estimated for the temperature range of 65-75°C was 137 kJ mol-1.

Notes: The catalytic activity of imidazole-containing polymers in the hydrolyses of substrates with poor leaving groups was examined. Hydrolyses of p-methoxyphenyl esters (Sn) catalyzed by poly[4(5)-vinylimidazole] (pvIm) in relation to imidazole (Im) indicates that both cooperative and hydrophobic interactions are operative. Hydrolyses of 3-methoxy-4-acyloxybenzoic acid substrates (Sn-) catalyzed by pvIm and a water-soluble copolymer, copoly[1-methyl-4-vinylimidazole/4(5)-vinylimidazole], exhibit many characteristics of enzyme-catalyzed reactions like saturation kinetics, bellshaped pH-rate profiles, and nonproductive binding. The importance of general-base, cooperative interactions for substrates with poor leaving groups and hydrophobic interactions in the formation of a stable catalyst-substrate complex in the case of long-chain esters is demonstrated. The interesting similarity between the Michaelis constants Km for the two polymer catalysts, pvIm and the copolymer, suggests that the common underlying principle involved in binding is hydrophobic interactions and the presence of N—CH3 group in the copolymer does not increase the hydrophobicity significantly. The pH-rate profiles for the hydrolyses of Sn- by pvIm show that the optimum pH is around neutrality, which indicated that the presence of neutral Im units to serve as nucleophiles and protonated Im units to serve as electrostatic binding sites is essential for maximum catalytic efficiency. The rate enhancement as a function of acyl chain length at different pH leads to the conclusion that a cooperative effect between electrostatic and hydrophobic interactions would reduce the nonspecificity of hydrophobic interactions and result in their better realization. An approximate calculation shows that the binding of S12-, in relation to S7-, with the copolymer in aqueous solution corresponds to the additional interactions of two methylene units.Our recent studies1-10 in the field of catalysis by polymeric imidazoles are oriented mainly toward the recognition of the significance of hydrophobic interactions. The role of hydrophobic interactions in enzymatic catalysis11-13 and synthetic macromolecular catalysts1-10,14-29 has been understood only recently. Hydrophobic interactions describe the tendency of nonpolar groups to associate themselves in aqueous solution30,31. Because the catalytic mechanism generally involves the prior complexation of the catalyst with the substrate and the catalyst-substrate complex is apolar, the influence of hydrophobic interactions in catalysis is conceivable. The favorable free energy of formation of hydrophobic interaction leads to better binding and better catalysis.In the present study we examined the hydrolytic reactions of the following substrates with poor leaving groups, catalyzed by imidazole-containing vinyl polymers, poly[4(5)-vinylimidazole] (pvIm), and a water-soluble copolymer, copoly[1-methyl-4-vinylimidazole/4(5)-vinylimidazole], ∼(1:1)M, Esters of varying acyl chainlength are chosen to determine the influence of hydrophobic interactions.

Notes: Glow discharge polymerizations in systems of trimethoxymethylsilane, trimethoxyvinylsilane, tetramethylsilane, and trimethylvinylsilane were compared by elemental analysis, infrared (IR) spectroscopy, and ESCA to reveal effects of methoxyl, methyl, and vinyl substituents. The substituent effects appeared in the chemical composition of the polymers formed especially at low W/FM values. Methoxy groups depressed the C/Si and H/Si ratios of the polymers rather than the methyl groups, whereas vinyl groups increased the C/Si and H/Si ratios. On IR spectra the polymers formed from silanes that contained methoxy groups showed fewer absorptions due to Si—H groups and strong absorptions due to Si—OH groups. The polymers from those that contained no methoxy groups showed absorptions of Si—H groups and no absorptions of Si—OH groups. These differences in the environment of Si atoms of polymeric chains also appeared in the Si2p core level spectra, thus indicating the different fragmentation patterns of the starting materials in glow discharge.

Notes: 5,5′-1,4-Phenylene-bis(2-cyano-2,4-pentadienoic acid) derivatives were prepared. Many of this series of compounds were found to be polymerizable in the crystalline state by irradiation with light of wavelength λ 〉 340 nm. The polymers obtained contain a benzene and a cyclobutane ring in the main chain and have a cyanoacrylate as the side chain. They are crystalline and some of them are soluble in organic solvents. Photopolymerization was found to follow a stepwise mechanism. The polymerization process is separable into an oligomerization and a subsequent polymerization by controlling the wavelength of the irradiating light; an oligomer was obtained by an irradiating light; an oligomer was obtained by an irradiating light of wavelength λ 〉 430 nm.

Notes: The effect of structure on the ability of hydroxamic acid polymers to chelate iron(III) was examined. The polymers were derived from acryloyl or methacryloyl backbones that bore side chains terminated in hydroxamic acids. The side chain length, which establishes the atomic chain distances between hydroxamic acid groups, had the most pronounced effect on the stability constant of the iron chelate. It was this atomic chain distance that determined how easily the three neighboring hydroxamic acids could fit the octahedral sphere of the iron. Other structural changes such as the presence or absence of methyl groups on the backbone or on the hydroxamic acid nitrogen had little measurable effect. The stability of the iron complexes appeared to be optimum at an 11-atom spacing between hydroxamic acids and decreased with shorter or longer spacing distances.

Notes: Direct polycondensation reaction of hydroxybenzoic acids with diphenyl chlorophosphate (DPCP) in pyridine was largely improved by carrying out the reaction in the presence of a formamide. Among the formamides examined, N,N-dimethylformamide (DMF), N,N-dimethylformamide, and N,N-dimethylacetamide were favorably used. A Vilsmeier adduct thus derived from DPCP and DMF was very effective especially for the preparation of high-molecularweight copolyesters from hydroxybenzoic acids. Copolymers of several combinations of hydroxybenzoic acids were prepared and their solubility and thermal properties were investigated. The polycondensations of aromatic dicarboxylic acids and bisphenols with the adduct were also studied.

Notes: Modified Belousov-Zhabotinskii (BZ) oscillation reactions were studied in the systems of ferroin or tris(2,2′-bipyridyl)ruthenium(II) dichloride or the polymerized ruthenium complex as electron transfer agents and sulfuric acid or polyethylenesulfonic acid (HPES) as acidic media. HPES was a good acidic medium for the chemical oscillation in spite of a long induction period. Moreover, chemical oscillation was observed at low concentration of HPES, where no oscillation was observed in the solution of sulfuric acid. On the other hand, no oscillation was observed in the solution of polystyrenesulfonic acid (HPSS). These results were discussed from the standpoint of the nature of polyelectrolytes.

Notes: Aromatic polyesters of high molecular weights were prepared by the direct polycondensation reaction of dicarboxylic acids and bisphenols or hydroxybenzoic acids with triphenylphosphine dichloride as a new condensing agent. Reaction conditions, including the amount of reagents and the concentration of monomer, solvent, and acid acceptor, were investigated. The aromatic polyester with the solution viscosity of 1.66 dL/g was obtained from bisphenol. A and terephthalic and isophthalic acid in quantitative yield under the optimum condition. The principal advantage of this condensing agent is that, based on the recycling system, recovered triphenylphosphine oxide can be reconverted to the reactive triphenylphosphine dichloride by treating with phosgene or oxalyl chloride.

Notes: In contradiction to reports from this and other laboratories, this study reports that the integrated Mayo-Lewis equation, or Meyer-Lowery equation, adequately describes the high-conversion free radical copolymerization of styrene and methylmethacrylate. The copolymerization was monitored by following the changes in the feed composition using NMR, as well as determination of the resulting copolymer compositions by NMR and UV. “Error in all Variables” statistical techniques were used to produce estimates of the reactivity ratios. The reactivity ratios estimated were, from feed composition, NMR, r1 (styrene) = 0.472, r2 = 0.454, from copolymer composition, UV, r1 = 0.497, r2 = 0.464, and NMR, r1 = 0.432, r2 = 0.422.

Notes: Photocrosslinkable poly(2-vinyloxyethyl cinnamate)'s with substituents in para position of cinnamoyl moieties were prepared cationically. Polymerizability of the monomers was markedly governed by the substituent and the glass transition temperatures of the polymers varied in the range of about 0 to 72°C. The photocrosslinking mechanism in relation to the photosensitivity of the polymers is discussed on the basis of spectroscopical studies.

Notes: The double salt 1 consisting of the hydrochloride of 6-amino-2,4-trans-hexadienoic acid and cadmium chloride in a 2:1 stoichiometry polymerizes in the crystalline state if exposed to UV or γ irradiation. A stereoregular polymeric ampholyte is formed in an extended chain macroconformation, embedded in an inorganic matrix. The crystal structure of the polymerized crystals and the solution properties of the polymer are reported. Polymerized crystals are triclinic, space group P1, a = 7.2144 Å, b = 7.2447 Å, c = 18.5936 Å, α = 104.49°, β = 96.631°, γ = 95.706°, Z = 2. The structure consists of 2-dimensional layers of polymer and inorganic CdCl6 octahedra alternatively stacked in the third dimension. The cadmium ions can be separated from the polymer by a precipitation as insoluble CdS. After separation from the inorganic material the polymer is soluble in strong acids and bases and insoluble in neutral water. From viscosity measurements of alkaline solutions of the polymer, an average molar mass of 4 × 104 g/mol can be deduced. The polymer selectively adsorbs divalent transition metal ions if suspended in an aqueous solution of transition metal salts. The structure of the resulting polymer-metal complexes is discussed.

Notes: Electroinitiated cationic copolymerization of indene and α-methylstyrene in dichloromethane has been investigated by constant potential electrolysis. The effects of copolymerization potential and the temperature on the copolymer composition was also studied. Constant potential electrolysis was found to be a suitable method to study the potential effects on copolymer compositions and the reactivity ratios of the monomers. The reactivity ratios were calculated according to integrated Lewis-Mayo equation.

Notes: The synthesis of copolymers intrachain charge transfer complexes having as donor structural units N-methyl-3-hydroxymethyl carbazolyl acrylate and as acceptor structural units acryloyl-3′-hydroxypropyl-3,5-dinitrobenzoate is presented. Charge transfer complexation in the copolymer and in the mixture of model compounds is analysed by NMR spectroscopy. Photosensitivity of the copolymers and of the corresponding mixture of model compounds is revealed by the increase of the ESR signal with illumination. Attempts to assign the ESR signal splitting to different radical structures are made. Besides an ESR signal increase dependent on light, a permanent increase in the number of spins is also noted as an effect of illumination.

Notes: Plasma-initiated polymerization is applied to acrylamide both in solid state and in solution. The effect of the amount of water, in addition to certain operational parameters such as applied vacuum, post polymerization period, and temperature, are well verified. Characteristics of polymers are determined by IR spectroscopy and X-ray diffraction studies as well as by intrinsic viscosity determinations.

Notes: To study the effect of micellar aggregation upon polymerization and polymer products, the polymerization of the micelle forming monomer allyldimethyldodecylammonium bromide (I) was investigated under both micellar and isotropic conditions. NMR spectroscopy and fluorescence quenching were employed to elucidate the structural characteristics and molecular weight of the polymer obtained by γ-ray irradiation. It was found that (I) undergoes effective polymerization in the micellar state, producing a polymer which consists of a mixture of head to tail and head to head configurations at the ratio 85/15, and has a mean molecular weight of 11,000 ± 1000 daltons.

Notes: The UV- and thermal-induced cis→trans isomerization of undoped polyacetylene (PA) films has been investigated. The results have shown that temperature and UV light promote the isomerization of PA with a similar mechanism. We suggest that the formation of paramagnetic defects in trans PA takes place by bond rehybridization, in agreement with previous hypotheses, and that both spin concentration and spin delocalization depend on the temperature of isomerization. It was found that under UV irradiation thermal cis→trans isomerization of polyacetylene also takes place at temperatures at which the sole thermal treatment isomerization is much lower or nil, and we suggest that the possibility of preparing trans PA under relatively mild conditions may lead to a better material.

Notes: The reactions of 1-[(dialkoxyphosphinyl)methyl]-2,4- and -2,6-diaminobenzenes (1) with various diisocyanates such as tolylene diisocyanate, methylenebis(4-phenylisocyanate), and hexamethylene-1,6-diisocyanate were studied for the synthesis of phosphorus-containing polyureas. Furthermore, diamines 1 were used as comonomers for preparing fire-resistant copolyureas. In addition, the corresponding common polyureas were synthesized for comparative purposes. All polymers were characterized by elemental analysis, inherent viscosity measurements, infrared (IR) and proton nuclear magnetic resonance (1H-NMR) spectroscopy, differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). The relatively low chemical reactivity of 1 toward diisocyanates was interpreted on the basis of their structural features. The phosphorus-containing polyureas showed a lower molecular weight, a lower polymer decomposition temperature, and a higher char yield than the corresponding common polyureas. Their fire-resistance was evaluated by determining the limiting oxygen index value.

Notes: The theories of hydrodynamic properties of macromolecules in solution leading to an invariant relationship between the values of the intrinsic viscosity, [η], the molecular weight, M, and the translational friction coefficient of the molecule, f, have been considered. The review of experimental data comprising as much as about 2000 fractions of various polymers suggests that for all flexible-chain and moderately rigid-chain molecules the hydrodynamic parameter A0 = kη0(M[η]/100)1/3f-1 is actually an invariant independent of the chain length and the thermodynamic strength of the solvent and for moderately polydisperse samples also independent of the degree of their polydispersity. For polymers with very rigid chains the parameter A0 has a high value over the experimentally investigated range of M. These conclusions make it possible to recommend the use of the following average experimental values of the invariant A0 for the determination of M of polymers from the values of [η] and f: for flexible-chain and synthetic polymers with moderately high chain rigidity (3.2 ± 0.2) · 10-10, for polymers with high chain rigidity (3.7 ± 0.4) · 10-10, and for cellulose derivatives and other polysaccharides with molecular dispersity of nonelectrolyte solutions (3.30 ± 0.30) · 10-10 erg deg-1 mol-1/3. The fact that the experimental value of A0 = 3.2 · 10-10 does not coincide with the value of A∞ = 3.8 · 10-10 erg deg-1 mol-1/3 predicted by the theories of translational friction and viscosity of macromolecules implies that the theoretical values of P∞ = 5.11 and Φ∞ = 2.8 · 1023 mol-1 are mutually incompatible and these theories require further development.

Notes: It is shown that cyclic oligomers present in poly(ethylene terephthalate) are excellent nucleating agents for the crystallization of polypropylene. However, rigorous purification of poly(ethylene terephthalate) showed that these oligomers are not responsible for the ability of the polymer to induce transcrystallinity when cooled in contact with polypropylene melts.

Notes: The aqueous polymerization of methacrylic acid (MAA) initiated by a Ce4+ -glycolic acid (GA) system was observed in a sulfuric acid medium at 35 ± 0.2°C in a nitrogen atmosphere. The rate of monomer disappearance was proportional to [MAA]1 and the rate of ceric ion disappearance was proportional to [GA][Ce4+]. An increase in the reaction temperature from 30 to 45°C raised the rate and the overall activation energy was 63 kJ/mol. The molecular weight increased with a rise in [MAA] and a reduction in [Ce4+]. The effect of varying [H2SO4] was also studied.