bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and properties of copoly(pyromellitimide–benzimidazopiperidone)
Authors: Yang Chin‐Ping 
Published: April 2003

AbstractSome new polymers and model compounds were obtained from the reaction of N,N‐protected glutamic anhydride with primary amines and the ring‐opening reaction was proved to belong to γ‐orientation. When the primary amine is aromatic ortho‐diamine, it was proved that the reaction route of ring‐closure dehydration of the ring‐opening addition products was through imidazolecarboxylic acid rather than imide amine, and at the last step it becomes imidazopiperidone. The corresponding polymer containing pyromellitdiimide and benzimidazopiperidone in the main chain was synthesized by a three‐step reaction of 2,2′‐pyromellitdiimidodiglutaric anhydride with 3,3′‐diaminobenzidine. In the first step, polyaminoamic acid having pyromellitdiimide ring was prepared in polar solvents. In the second step, the conversion of polyaminoamic acid to the copolyimidoimidazole acid was carried out thermally in solution or solid at 140–200°C. At last, the conversion of copolyimidoimidazole acid to the copolypyromellitimidobenzimidazopiperidone was performed either thermally (300°C) or by chemical means. Infrared spectra and NMR spectra were studied and compared with corresponding model compounds. Form solubility and TG analysis, the polymer belongs to a heat‐resistant polymer.
Synthesis of polybenzimidazoles with sulfonic acid groups
Authors: Uno Keikichi , Niume Kazuma , Iwata Yasuhisa , Toda Fujio , Iwakura Yoshio 
Published: April 2003

Abstract2‐Sulfoterephthalic acid (STA) and disulfoisophthalic acid (DSIA) were synthesized through the sulfonation and the oxidation of m‐ and p‐xylene. The polycondensation reactions of STA and DSIA with aromatic tetraamines gave polybenzimidazoles which contained one or two sulfonic acid groups for each repeating unit. The polymer obtained was soluble in sulfuric acid, some organic solvents, and aqueous strong alkaline solution. The polymers were stable up to 400°C, but they gave polybenzimidazoles above 400°C by eliminating sulfonic acid groups, instead of ring closure.
Anionic polymerization of ϵ‐caprolactam activated with phosphadiazines
Authors: Shalaby S. W. , Reimschuessel H. K. 
Published: April 2003

AbstractPhenylphosphonyl‐N,N′‐biscaprolactam (I) and phenylphosphonyl‐N,N′‐bis(3,5‐dimethylpyrazole) (II) were synthesized and found to be very efficient activators for the anionic polymerization of caprolactam when used in combination with strong bases such as sodium caprolactam. Polymers obtained in the presence of I and II had generally higher molecular weights and were less sensitive to thermal degradation upon molding than those whose preparation entailed the use of N‐acetyl‐caprolactam (III) as an activator. Thermal behavior and tensile properties indicated that the structure of these polyamides differs from that encountered in nylon 6 prepared with conventional anionic catalyst systems.
Syntheses and reactions of functional polymers. XCIII. Syntheses of polymers containing the N‐(4‐hydroxy‐3‐nitrophenyl)succinimide structure in the chain and the use of these activated polymer esters of N‐blocked amino acids or peptides
Authors: Teramoto Takero , Narita Mitsuaki , Okawara Makoto 
Published: April 2003

AbstractPolymers containing the N‐(4‐hydroxy‐3‐nitrophenyl)succinimide residue were designed in order to achieve acyl activation of a reacting carboxylic acid in the solid phase. These polymers were prepared through the following three routes: (a) styrene was allowed to copolymerize with N‐(4‐hydroxy‐3‐nitrophenyl)‐ or N‐(4‐acetoxy‐3‐nitrophenyl)maleimide, (b) styrene was copolymerized with N‐(4‐acetoxyphenyl)maleimide in the presence of divinylbenzene (DVB), and the copolymer obtained was hydrolyzed and nitrated, (c) a copolymer of maleic anhydride and styrene was reacted with p‐aminophenol, followed by nitration. The polymers prepared by routes b and c were converted to the activated polymer esters of N‐blocked amino acids and peptides by using dicyclohexylcarbodiimide (DCC). The acylated polymers thus obtained were treated with amino acid esters and found to give peptides quantitatively without racemization.
Thermal decomposition and volatilization of poly(α‐olefins)
Authors: Seeger Michael , Gritter Roy J. 
Published: April 2003

AbstractThe thermal decomposition of normal alkanes and linear poly(α‐olefins) was found to occur predominately by random scissions, followed by volatilization into an open system. To show these processes the fragment distribution from high molecular weight linear polyethylene (fragments to C55), n‐alkanes, polypropylene, and polyisobutylene (fragments to C60) are reported and discussed in depth. Based on the results, a mechanism of random scissions followed by volatilization is postulated for polyethylene and n‐alkanes as well as for polyisobutylene and polypropylene. Polystyrene is shown not to follow the same mechanism, for little evidence for fragments above trimers was found. In addition, temperature rise–time measurements at the pyrolyzer probe are reported and explained.
Analysis of plasma‐polymerized hydrocarbons by pyrolysis/gas chromatography
Authors: Seeger M. , Gritter R. J. , Tibbitt J. M. , Shen M. , Bell A. T. 
Published: April 2003

AbstractPlasma‐polymerized oils, films and powders obtained from ethylene, acetylene, butadiene, and benzene were characterized by flash pyrolysis and gas chromatography (P/GC). None of the pyrograms resembled those of commercial polyethylene, polybutadiene, or polystyrene. Each of the plasma‐polymer pyrograms did exhibit essentially the same fragments up to C8, albeit in a different distribution, indicating that all samples are structurally similar. Analysis of the P/GC data shows these materials to contain a random arrangement of side chains, crosslinks, double bonds, and aromatic structures. Changes in the fragment distribution were obvious when the sample was a powder, solid film, or oily film produced from the same monomer. It was shown that powder products generally have a higher concentration of branches and/or crosslinks than the oil or film products. There are also differences in the pyrograms of products of the same form derived from dissimilar monomers. The results obtained from P/GC generally support those derived from infrared or NMR measurements performed earlier.
Preparation and photolysis of poly‐p‐ethylacrylophenone and poly‐p‐chloroacrylophenone and their copolymers with styrene and methyl methacrylate
Authors: Lukáč I. , Pilka J. , Kulíčková M. , Hrdlovič P. 
Published: April 2003

AbstractPoly‐p‐ethylacrylophenone (PPEtAP) and poly‐p‐chloroacrylophenone (PPClAP) and their copolymers with styrene (PEtAP/S) and (PClAP/S) and with methyl methacrylate (PEtAP/MMA) and (PClAP/MMA) were prepared. Quantum yields of main‐chain scissions at 366 nm at room temperature in benzene solution are of the same order as those of the unsubstituted polyacrylophenone and its copolymers. Substitution with chlorine and ethyl group in the para position compared to the unsubstituted polyacrylophenone and its copolymers leads to an increase of the lifetime for the n–π* excited triplet state, as is evident from the measured quenching constants of photolysis. The low‐temperature emission spectra of the copolymers are similar to the spectra of the model compounds in a polymer film. For the homopolymer, however, the character of the emission spectrum changes considerably.
Mechanism of coating by electropolymerization on metal cathodes from zinc chloride solutions of acrylamide
Authors: Collins George L. , Thomas Norman W. 
Published: April 2003

AbstractElectrocoating by polymerization of aqueous zinc chloride solutions of acrylamide and methylenebisacrylamide has been reexamined. The original investigators of this system proposed a mechanism in which the initiation was formed by electrochemical reduction of a zinc complex of molecular oxygen. That mechanism is not compatible with the present findings that polymerization occurs when oxygen is excluded by nitrogen bubbling. Evidence is presented for the intervention of a zinc complex with monomer. The pH dependence of electrocoating indicates that the species involved is ZnOH+. Failure to achieve coating in acidic solutions of monomers in the absence of zinc points to a multisite attchment of the metal species to monomer in a ring structure. The interpretation is consistent with the observed electropolymerization of N,N‐dimethylacrylamide and with the correlation of electropolymerizability with shifts detected in laser Raman spectra of selected acrylic monomers.
Polymerization of diallyl phthalate in solution by γ‐radiation
Authors: Divakar R. S. , Rao K. N. 
Published: April 2003

AbstractThe polymerization of diallyl phthalate has been studied in two solvents, benzene (GRadical = 0.7) and chloroform (GR = 11.2), γ‐radiation being used to investigate the effect of the solvent on the rates of polymerization and also chain transfer to the solvent. Kinetic analysis shows that in benzene solution the initiating species come almost exclusively from the monomer, but in chloroform they arise only from the solvent. The latter was further confirmed from the chlorine analysis of the polymer wherein chloroform appears to have telomerized with diallyl phthalate. In neither of the solvents was high molecular weight polymer obtained. The kp/kt1/2 for the polymerization of DAP was found to be 3.3 × 10−4 and 1.17 × 10−3 in benzene and chloroform solutions, respectively. The chain‐transfer constant CS was 11.25 × 10−3 and 9.75 × 10−3 for benzene and chloroform, respectively.
Polymérisation anionique amorcée par les composés lamellaires du graphite et du lithium
Authors: Merle G. , Pascault J. P. , Pham Q. T. , Pillot C. , Salle R. , Golé J. , Rashkov I. , Panayotov I. , Guérard D. , Hérold A. 
Published: April 2003

AbstractIn the present work, we use the binary insertion compound LiC12 to polymerize styrene, methyl methacrylate, butadiene, isoprene, and to copolymerize isoprene and styrene in various hydrocarbon solvents (aromatics and aliphatic) and etheral solvents. We show that the styrene polymerization in aromatic solvents gives better yields than in the etheral solvents, the polymer being atactic. Methyl methacrylate does not polymerize in toluene but does so completely in DME. More generally, the yields of polymerization are better with KC37 than with LiC12 because of the different capacities of the monomer to get into the carbon layers. The polymerization of dienes with LiC12 shows that the microstructures of the polymer obtained in π‐or n‐donor solvents are similar to the ones obtained by homogenous polymerization with Li cation in such solvents. However, for isoprene in cyclohexane, the results are different. The isoprene styrene copolymers are statistical ones and the mean length of styrene blocks is less than 5. The monomer interaction with the insertion compound and the growing chain geometry between the carbon layers are the facts which control either the stereospecificity of the polymerization or the selectivity of the copolymerization.
Metal‐containing crosslinked polyester resins by combined polyesterification and polymerization of curable mixtures based on divalent metal salts of mono(hydroxyethyl)phthalate
Authors: Matsuda Hideaki 
Published: April 2003

AbstractPreparations of metal‐containing crosslinked polyester resins based on divalent metal salts of mono(hydroxyethyl)phthalate were investigated by the cure, by combined polyesterification and polymerization, of curable mixtures prepared from above metal salts, maleic anhydride, glycidyl methacrylate, and methyl methacrylate. The curable mixtures containing Ca showed lower viscosity than those containing Mg. They were subjected to curing reactions in the presence of peroxide and under photoirradiation, respectively. In the cure, polyesterification and polymerization proceeded simultaneously smoothly, giving metal‐containing cured resins. Generally, the peroxide‐cured resins showed better physical properties than the photo‐cured resins. Especially, the former resins with high metal content showed high compressive strength and Rockwell hardness. Further, resistance to chemical attack and boiling water and thermal behavior are also discussed.
Toxic gas evolution from polymers: Evolution of hydrogen cyanide from polyurethanes
Authors: Jellinek H. H. G. , Takada K. 
Published: April 2003

AbstractThe thermal oxidative degradation of two aromatic and one segmented polyurethane has been studied, with special emphasis on HCN evolution over a range of temperatures and oxygen concentrations. A tentative mechanism for HCN formation has been presented. Other gaseous products were ascertained by chromatography. Infrared spectra during degradation were measured, and the extent of crosslinking was also determined. It is shown that HCN evolution can be inhibited by copper or its oxide.
Semiconducting organic polymer from polyacrylamide–Cu++ chelate and iodine
Authors: Higashi Fukuji , Cho Chong Su , Kakinoki Hideo , Sumita Osao 
Published: April 2003

AbstractSemiconducting organic polymer was obtained by the modification of polyacrylamide (PAAm)–Cu++ chelate with iodine in acetone. Favorable conditions for preparing the chelate effective for the conduction were investigated. Surface resistivities were affected by the amounts of cupric salts and iodine, satisfactory results being given by about 25 wt % of the salts based on PAAm and more than 1 wt % of iodine on the chelate. The conductivity was also varied with the degree of neutralization of the chelate in solution, and optimal values were obtained by addition of about an equimolar amount of potassium hydroxide to cupric salts. Effective structures of the polymer chelate in solution were assumed on the basis of the visible and the NMR spectra and potentiometric titration.
Anionic polymerization initiators containing protected functional groups. II
Authors: Schulz D. N. , Halasa A. F. 
Published: April 2003

AbstractAn organolithium reagent substituted with a primary amine‐protecting group [i.e.,N(TMS)2] has been prepared and used to polymerize 1,3‐butadiene and isoprene. A method is described for converting the resultingN(TMS)2‐containing polydienes intoNH2‐containing polymers. Both N(TMS)2‐ and NH2‐terminated polydienes have been characterized with regard to microstructure, Mn, and Mw/Mn data, as well as qualitative and quantitative end‐group analyses. The described preparative procedures represent a convenient route to the elusive primary amine‐terminated polydienes.
Polymerization of acetylenic derivatives. XXX. Isomers of polyphenylacetylene
Authors: Simionescu C. I. , Percec V. , Dumitrescu Svetlana 
Published: April 2003

AbstractCis‐transoidal (orange, soluble, and of low crystallinity) and cis‐cisoidal (red, insoluble, and highly crystalline) polyphenylacetylenes (PPA) were prepared by Ziegler‐Natta catalysts and trans‐cisoidal (yellow, soluble, and amorphous) polyphenylacetylenes were prepared by using phosphine complexes, TiCl4 and by thermal initiation. The cis‐transoidal and cis‐cisoidal structures isomerize thermally in the solid state above 100°C. In solution the cis‐transoidal structure isomerizes above 80°C. The polymers obtained by thermal isomerization are soluble, amorphous, and have a trans‐cisoidal structure. At temperatures higher than 120°C the cis–trans isomerization is accompanied by cyclization and by scission of the polymer chain. A method was developed for determination of cis content of cis‐transoidal and cis‐cisoidal polyphenylacetylenes.
Photophysical properties of poly‐2‐phenyl‐5‐(p‐vinyl)‐phenyloxazole
Authors: McInally I. , Soutar I. , Steedman W. 
Published: April 2003

Abstract2‐Phenyl‐5‐(p‐vinyl)phenyloxazole (POS) has been synthesized. Copolymers of POS with styrene and the homopolymer poly–POS have been prepared. The polymers have been characterized through measurements of fluorescence decay times (using synchrotron radiation for excitation) and examination of excimer formation in the homopolymer. Fluorescence decay times of 0.6(±0.4) nsec and 9 (±0.2) nsec have been recorded at 298°K in toluene solution for monomer and excimer, respectively. Poly‐POS exhibits excimer formation characterized by an activation energy of 5.9(±0.5) kJ/mole and a binding energy of 17.0(±1.0) kJ/mole.
Suspension polymerization of vinyl chloride initiated by in situ generated diisobutyryl peroxide
Authors: Barter James A. , Kellar David E. 
Published: April 2003

AbstractIt was found that diacyl peroxides can be formed in situ in a polymerization medium by the reaction of an acid anhydride with hydrogen peroxide. For the specific application to aqueous vinyl chloride polymerization, an initiator system based on the base‐catalyzed reaction of isobutyric anhydride with hydrogen peroxide to produce diisobutyryl peroxide gave very good results. In contrast, the acid chloride was completely ineffective as a peroxide precursor in this reaction. Studies pointing to diisobutyryl peroxide as the initiating species; investigations of reactant stoichiometry; and comparison of the in situ system with preformed diisobutyryl peroxide were conducted. It was shown that this system makes possible the polymerization of vinyl chloride at 30°C at rates comparable to those obtained with dialkyl peroxydicarbonates at 50°C, thus demonstrating the ability of this system to initiate vinyl chloride polymerization at low temperature. The rates of vinyl chloride polymerization with the use of different concentrations of in situ diisobutyryl peroxide at 30, 40, and 50°C were determined. Similarly, polymerization rates with the use of combinations of in situ diisobutyryl peroxide and n‐propyl peroxydicarbonate were determined. The data obtained demonstrate rapid initiation of the polymerization reaction and a reduction in polymerization time made possible by this dual initiator system. These results were verified in pilot‐plant and commercial‐scale PVC polymerizations.
Polymerization of acrylonitrile initiated by thiourea–chromium(VI) redox system
Authors: Nayak Padma L. , Samal Rajani K. 
Published: April 2003

AbstractThe kinetics of polymerization of acrylonitrile initiated by Cr(VI)–thiourea and Cr(VI)–ethylene thiourea have been studied at 35, 40, and 45°C in nitrogen. The rates of polymerization and of disappearance of Cr(VI) were measured. Chromic acid alone did not initiate the polymerization under deaerated and undeaerated conditions. On the basis of the experimental observation of the dependence of the rate of polymerization Rp, the rate of Cr(VI) disappearance, –Rm, etc., on various variables, a suitable kinetic scheme was proposed and various rate and energy parameters were evaluated.
Photoinitiation and electroinitiation in the polymerization of 2‐vinylnaphthalene
Authors: Davies D. H. , Phillips D. C. , Smith J. D. B. 
Published: April 2003

AbstractThe zinc chloride‐catalyzed polymerization of 2‐vinylnaphthalene (VN) with both photoinitiation and electronitiation methods was examined. Good yields were obtained with both methods, the electroinitiated process being somewhat faster. The mechanism for polymerization initiation was investigated through a detailed comparison of the kinetics. Both initiation methods show a similar response to increasing input energy and to change in salt to monomer mole ratio. Both methods indicate formation of a ZnCl2–(2‐VN)2 complex as intermediate with the formation of the species being rate‐determining. These results, together with other similar investigations, are then used to deduce a mechanism that involves the formation of an electronically excited donor–acceptor complex. It is argued that in certain salt‐stabilized, electron‐delocalized, aromatic systems, such excitation is possible in electroinitiation.
Photoreversible reactions of polymers containing cinnamylideneacetate derivatives and the model compounds
Authors: Tanaka Hideaki , Honda Koichi 
Published: April 2003

AbstractPhotoreversible reactions of 1,4‐butanediol dicinnamylideneacetate(BCA) and its photocyclized compound (BCD), the model compounds for poly(vinyl cinnamylideneacetate), were studied. They exhibited an excellent photoreversibility in a rigid medium at 77°K. The quantum yield of dimerization in the rigid medium is much larger than that in the solution and approximately equal to that in polymer film. Poly(vinyl esters) of substituted cinnamylideneacetic acids also showed photoreversibility to various extents, depending on the substituent. Poly(vinyl α‐cyanocinnamylideneacetate) showed the best photoreversibility among the series, reflecting the least amount of side reaction upon the photodimerization.
Photoaddition of maleic anhydride to unsaturated polymers in homogeneous solution, solid polymer–solution, and solid polymer–vapor systems
Authors: Tazuke Shigeo , Kimura Hitoshi 
Published: April 2003

AbstractPhotoreactions of maleic anhydride (MAH) with unsaturated olefinic polymers such as 1,2‐polybutadiene, 1,4‐polybutadiene, block copolymer of styrene and butadiene, polystyrene, poly(styrene‐co‐isoprene), and poly(styrene‐alt‐methyl methacrylate) were investigated in air. When the polymers have olefinic unsaturation, the addition of MAH to the polymers in homogeneous solutions proceeded efficiently by a chain mechanism, and the quantum yield of the photoaddition of MAH was greater than unity under irradiation at λ > 310 nm. From the effects of solvent and photosensitizer, a radical chain mechanism involving crosslinking of the polymers by MAH molecules was suggested. Together with the spectroscopic results, the reaction mechanism was discussed. The photoaddition reaction was then applied to the surface photomodification of polymer films. Photoreactions were conducted at the interphase between solid polymer and acetone solution of MAH and also at the interphase between solid polymer and gaseous MAH. Irradiation by a 300‐W high‐pressure mercury lamp could bring about considerable modification of the surface properties of the polymers, which then show improved wettability and dyeability. From the oxygen permeation experiments, the present interfacial phototreatment was shown to provide a double‐layered polymer film in which one side of the film is polar and hydrophilic while the other side is nonpolar and hydrophobic.
Synthesis of polyamides from active N,N′‐diacylbis‐2‐benzothiazolones and diamines under mild conditions
Authors: Ueda Mitsuru , Sato Akira , Imai Yoshio 
Published: April 2003

AbstractThe aminolysis of N‐benzoyl‐2‐benzothiazolone was studied in model systems and was found to give excellent yields of N‐substituted benzamides at room temperature. Solution polycondensation of new bisamides, N,N′‐adipoylbis‐2‐benzothiazolone and N,N′‐isophthaloylbis‐2‐benzothiazolone, proceeded fairly slowly with both aromatic and aliphatic diamines at room temperature to yield polyamides having inherent viscosities up to 1.5. Hexamethylphosphoramide was the best polycondensation medium among some polar aprotic solvents for the formation of high molecular weight polyamides. The high reactivity of the N‐acyl‐2‐benzothiazolones was discussed in relation to excellent leaving nature and intramolecular general base catalysis of the benzothiazolone moiety.