bluuebunny/crossref_metadata_2025_split huggingface dataset:
Radiation‐induced, solid‐state polymerization of derivatives of methacrylic acid. I. Postirradiation polymerization of zinc methacrylate
Authors: O'Donnell J. H. , Sothman R. D. 
Published: April 2003

AbstractThe postirradiation polymerization of the crystalline, anhydrous, monohydrate, and dihydrate forms of zinc methacrylate was studied. The anhydrous salt polymerized readily in the temperature range 50–150°C., the monohydrate did not polymerize at all, and the dihydrate polymerized at about 100°C. Aging of the anhydrous salts greatly affected the rate of polymerization; this was shown to be due mainly to the formation of peroxides by reaction with air. Polymerization could be initiated thermally, without irradiation, in monomer which had been aged in contact with air, apparently by decomposition of the peroxides. The rate of the postirradiation polymerization was increased when air was present during irradiation and decreased when air was present during polymerization. The rate of polymerization increased with temperature, corresponding to an apparent activation energy of 10 kcal./mole. The dihydrate lost one molecule of water rapidly under vacuum at 20°C. and slowly on heating at 50°C. in a sealed vessel, forming a crystalline monohydrate. Slow thermal polymerization and rapid postirradiation polymerization occurred at 100°C. without the formation of any monohydrate, indicating that the polymerization was concurrent with the phase change.
Radiation‐induced polymerization of isoprene in aqueous solution of silver nitrate
Authors: Fujioka Syuji , Ichimura Tadao , Shinohara Yasuo , Hayashi Koichiro 
Published: April 2003

AbstractThe rate of radiation‐induced polymerization of isoprene in aqueous solution of silver nitrate is 20–50 times as fast as the rate of radiation‐induced polymerization of pure isoprene. The formation of a 1:2 complex of isoprene and silver nitrate was confirmed spectrometrically, and this complex seems to polymerize by attack of an active species. The equilibrium constant Kf and the extinction coefficient E of the complex were estimated to be 0.18 and 1.4, respectively. The polymerization mechanism was concluded to be a radical one, based on the effects of inhibitors. The polyisoprene obtained had a crosslinked structure, was insoluble, and did not give a distinct melting point. The 1,2 structure was the predominant polyisoprene configuration. This was interpreted on the basis of the frontier electron density of isoprene.
Hyperelectronic polarization in macromolecular solids
Authors: Hartman Roger D. , Pohl Herbert A. 
Published: April 2003

AbstractHyperelectronic polarization may be viewed as the electrical polarization in external fields due to the pliant interaction with the charge pairs of excitons, in which the charges are molecularly separated and range over molecularly limited domains. It is particularly pronounced in molecular solids composed of long polymeric molecules having extensive regions of electronic orbital delocalization. Hyperelectronic polarization is regarded as the principal contributor to the high polarizabilities of the following five macromolecular solids: four polyacene quinone radical polymers formed by condensation of aromatic hydrocarbon derivatives with aromatic acids and poly(Cu(II)‐N,N′‐ dimethyl rebeanate). The first four polymers at 100 hz had dielectric constants of 1800–2400, decreasing to about 58–100 at 100,000 hz, with relaxation times of 10−3 to 10−4 sec. A sixth polymer, a Schiff‐base condensate of 1,4‐napthaquinone and p‐toluene diisocyanate, however, showed little hyperelectronic polarization, displaying a dielectric constant of 10, constant over 100–100,000 hz. By simple arguments it is shown that the relaxation times and the frequency response of conduction are consonant with the proposed model of charges roaming over long molecular domains (up to 4000 A.) but restricted by molecular boundaries.
Anion radicals of polyphenylsiloxanes
Authors: Eargle D. H. , Moniz W. B. 
Published: April 2003

AbstractThe anion radicals of a number of siloxanes bearing phenyl and methyl substituents have been prepared by metal reduction. The cleavage and reaction mechanisms of these radica s have been studied by ESR, and interpretations have been made regarding the structures of the radicals.
Room‐temperature polycondensation of β‐amino acid derivatives, I. Polyamide from amino alcohols and acrylates
Authors: Sanui Kohei , Asahara Tomohiko , Ogata Naoya 
Published: April 2003

AbstractAcrylates, such as ethyl acrylate, add with amino alcohol to form N‐(hydroxyalkyl) β‐alanine ester and room‐temperature polycondensation follows, forming polyamide in the presence of a basic catalysts, such as alkali metal alkoxide. The reaction medium has an influence on the course of the polycondensation; that is, N‐(hydroxyalkyl) polyamide is formed in methanol solution and polyamide ether in other solvents, such as tetrahydrofuran. These two courses of the room‐temperature polycondensation have been studied, and the reaction mechanism is discussed in this paper.
Effect of urethane groups on the reaction of alcohols with isocyanates
Authors: Smith H. A. 
Published: April 2003

AbstractRecently Reegen and Frisch reported the urethane catalysis of the alcohol–isocyanate reaction. We have made similar observations on a broader variety of reactants and catalysts including mono‐ and polyfunctional reactants, and tertiary amine, cobalt salt, and tin salt catalysts. We have found that the point in the reaction when urethane catalysis occurs is a function of the catalyst, the number of hydroxyl groups in the alcohol, and the effect of the interaction of the catalyst, alcohol, and isocyanate on the geometry of the reactive complex.
The radiation‐induced copolymerization of tetrafluoroethylene and 3,3,3‐trifluoropropene under pressure
Authors: Brown Daniel W. , Wall Leo A. 
Published: April 2003

AbstractA study was made of the gamma‐ray‐induced copolymerization of tetrafluoroethylene and 3,3,3‐trifluoropropene. Copolymerizations were carried out at 100°C. and 5000 atm. pressure and at 21°C. and various pressures up to 8000 atm. The reactivity ratios calculated from the composition data indicate that the propagation rate constants favor addition of trifluoropropylene by a factor of 3–7; individual values depended little on the polymerization pressure and temperature. Polymerization rates changed little with monomer composition between 0 and 75% tetrafluoroethylene; between 75 and 95% tetrafluoroethylene they increased by a factor of 10. As many as 850,000 molecules were polymerized per 100 e.v. absorbed. The copolymers are soluble in hexafluorobenzene at 29.6°C. if they contain less than 70% tetrafluoroethylene. Intrinsic viscosities range from 0.1 to about 10 dl./g. From various considerations it appears likely that the degree of polymerization is about equal to the kinetic chain length in high‐pressure polymerizations at 21°C.; at autogenous pressure or at 5000 atm and 100°C., monomer transfer reduces the value considerably.
Alternating copolymerization through the complexes of conjugated vinyl monomers–alkylaluminum halides
Authors: Hirooka Masaaki , Yabuuchi Hiroshi , Iseki Jiro , Nakai Yasuto 
Published: April 2003

AbstractA vinyl monomer that has the nitrile or carbonyl group conjugated to the CC double bond, such as acrylonitrile, methyl acrylate, and methyl methacrylate, forms a complex with an alkylaluminum halide, and the complex reacts spontaneously with a hydrocarbon monomer such as styrene, propylene, or ethylene, giving a high molecular weight copolymer. The copolymers always contain the two monomer units in 1:1 ratio. Thus styrene, copolymerized with methyl acrylate or methyl methacrylate in the presence of ethylaluminum sesquichloride in homogeneous toluene solution, gives such an equimolar copolymer regardless of the initial monomer compositions. The NMR spectra of these copolymers are distinctly different from those of the equimolar copolymers obtained with azobisisobutyronitrile as initiator and have simpler and well separated patterns. The copolymers and the corresponding radical copolymers appear to be amorphous, judged by their x‐ray diffraction patterns and their differential thermal analyses. Their infrared spectra resemble each other very closely. Hence, the difference in the NMR spectra may be ascribed to the matter of the sequence distribution. The infrared spectrum of ethylene–methyl acrylate copolymer shows no absorption near 720 cm.−1 due to the methylene sequence arising from ethylene–ethylene linkage. These experimental data lead to the inference that the equimolar copolymers obtained in this work may have an alternating sequence.
Radical grafting on lignin. Part I. Radiation‐induced grafting of styrene onto hydrochloric acid lignin
Authors: Koshijima Tetsuo , Muraki Einosuke 
Published: April 2003

AbstractBy irradiation with gamma rays styrene was grafted onto hydrochloric acid lignin. When the graft polymers were subjected to nitrobenzene oxidation, the vanillin yields indicated two kinds of reaction occurring in the grafting. Polystyrene branches were separated from the graft polymers, and their M̄n were determined osmometrically. At grafting ratios of up to 100 the vanillin yields diminished proportionately with increasing grafting, and the M̄n of the branches, 5000, was unchanged. At grafting ratios of more than 100 the vanillin yields were constant, independent of the ratios, but the M̄n values of the branches increased with grafting. Paper chromatography of the aromatic acids obtained by oxidation of methylated lignin and the graft polymer indicated that isohemipic and metahemipic acids were more abundant in the acid fraction of the graft polymer than in the lignin itself. A qualitative mass analysis of the gaseous products evolving from the irradiated lignin showed the presence of hydrogen molecules only. Gamma‐ray radiation brought about no change in the yields of vanillin. It was therefore concluded that radiation grafting on lignin at grafting ratios of less than 100 proceeded through the addition of the styrene polymer radicals to the aromatic nuclei of the lignin and that then branches propagated from the aliphatic part of the lignin, where CH bond scission had been caused by the irradiation. The grafting sites of lignin would be C‐5 and C‐6 of the guaiacyl nucleus and, probably the β and γ carbon atoms of the aliphatic side chain of the lignin.
Cationic polymerization of α‐methylstyrene catalyzed by boron trifluoride etherate in 1,2‐dichloroethane under an electric field
Authors: Sakurada Ichiro , Tanaka Yoshinobu , Ise Norio 
Published: April 2003

AbstractThe cationic polymerization of α‐methylstyrene with boron trifluoride etherate was studied in 1,2‐dichloroethane under an electric field. The electric field was again found to increase the polymerization rate. This field effect was independent of monomer concentration, as was found previously. The effect, however, became greater as the catalyst concentration was lowered, unlike previous findings with various cationic systems. Furthermore, the field effect became smaller with rising temperature, whereas it had been practically independent of temperature in previous studies. The field effect increased linearly with the field strength. At 2.7 kv./cm. the rate was almost tripled. The field effect was small at lower dielectric constants, as had been observed previously. The large field effects observed and their “exceptional” behavior led to the interpretation that “partial” desolvation of free, growing chain ends, in addition to the field‐facilitated dissociation, was responsible for the effect. Specific conductivities of polymerizing solutions and catalyst solutions were measured and are discussed.
Copolymerization of allyl esters of some fatty acids
Authors: Chow Roberta C. L. , Marvel C. S. 
Published: April 2003

AbstractAttempts have been made unsuccessfully to homopolymerize a number of allyl esters of substituted fatty acids by radical initiation in emulsion systems. Copolymerizations of these allyl esters with styrene, methyl methacrylate, and vinyl chloride have been investigated. Of these comonomers, styrene and methyl methacrylate do not copolymerize well with the allyl esters, whereas vinyl chloride does. Reactivity ratios for the radical copolymerization of allyl 11‐iodoundecanoate, M1, and vinyl chloride, M2, determined at 60°C. in benzene, are r1 = 0.42 and r2 = 1.64. A copolymer of allyl 10, 11‐dibromoundecanoate and vinyl chloride was fractionated and found to be fairly homogeneous.
Determination of elementary rate constants of styrene polymerization catalyzed by rhenium pentachloride
Authors: Kamachi Mikiharu , Miyama Hajime 
Published: April 2003

AbstractRate constants of the propagation and transfer processes for the cationic polymerization of styrene catalyzed by rhenium pentachloride were obtained by kinetic analysis. Also, dependence of the propagation constant on the dielectric constant of the system was examined. Comparison of these data with those of the other systems with different catalysts suggests that the present catalyst is a strong Lewis acid and the size of the counterion is very large.
The interaction of ions with nylon. Part I. Absorption of simple acids
Authors: Marshall J. 
Published: April 2003

AbstractThe paper describes the titration relations for nylon 66 samples of different endgroup contents both for aqueous and alcohol solutions. The effect of temperature change is also considered. The results are consistent with a zwitterion structure of the nylon, carboxyl groups being protonated on acid titration. The acid groups are shown to be weaker than the corresponding monomeric acids in aqueous solution, owing to their environment inside the polymer. Individual ionic affinities are calculated from the experimental absorption isotherms and are in agreement with values obtained from a simple electrostatic theory. The low sulfate ion affinity can be explained by assuming interaction for this ion with single, fixed, isolated sites.
The polymerization of 1,4‐pentadiene to [3.3.1]bicyclo‐linked chains
Authors: Trifan Daniel S. , Shelden Ronald A. , Hoglen John J. 
Published: April 2003

Abstract1, 4‐Pentadiene has been polymerized by Ziegler‐Natta catalysts to give amorphous polymers which are up to 64 wt.‐% soluble. The polymers all have residual unsaturation which is substantially less than one double bond per mer, some as low as 0.1 double bond per mer. The polymerizations proceed by an unusual double inter‐, double intramolecular cyclopolymerization mechanism leading to the formation of [3.3.1] bicyclic repeat units. Some main‐chain (internal) unsaturation as well as pendant‐group (external) unsaturation is observed. The latter results from incompletely cyclized 1,4‐pentadiene units. The former is due to some concurrent isomerization of 1,4‐ to 1,3 pentadiene, which then copolymerizes with the 1,4 diene. The extent of isomerization varied with the catalyst system used. The soluble polymer fractions were brittle for internal unsaturations of less than about 0.05 double bond per mer and were viscous for higher values. The insoluble fractions were brittle and are believed to be lightly crosslinked.
Preparation of polymers containing sugar residues
Authors: Iwakura Yoshio , Imai Yohji , Yagi Kohji 
Published: April 2003

AbstractThe synthesis of five different polymers containing sugar residues on side chain is described. 1‐O‐Methacryloyltetra‐O‐acetyl‐D‐glucose, 1‐O‐methacryloyltetra‐O‐acetyl‐D‐galactose, and 6‐O‐methacryloyltetra‐O‐acetyl‐D‐glucose were prepared and polymerized. The polymethacrylates obtained were converted into water‐soluble polymers by removing the acetyl protective group with sodium methoxide. 6‐O‐Methacryloyldiisopropylidene‐D‐galactose was also prepared and polymerized. The isopropylidene protective group was removed by acid hydrolysis. Poly (N‐methacryloylglucosamine) was prepared directly by the polymerization of N‐methacryloyl‐D‐glucosamine without the use of any protective group.
Synthesis and thermogravimetric analysis of diol‐linked tetrameric hexaphenyldichlorophosphonitrile polymers
Authors: Bilbo A. J. , Douglas C. M. , Fetter N. R. , Herring D. L. 
Published: April 2003

AbstractSeveral high molecular weight polymers have been prepared from the reactions of hexaphenyldichlorophosphonitrile tetramer with p,p′‐biphenol, 4,4′‐oxydiphenol, resorcinol, and benzidine. A simple fractionation procedure yielded samples of the biphenol‐linked polymer with molecular weights of approximately 500,000. DTA and TGA studies of this polymer in a variety of environments indicate thermal degradation is initiated in the phosphonitrile ring.
Solid‐state polymerization of maleimide by 2,2′‐azobisisobutyronitrile
Authors: Kagiya Tsutomu , Izu Masatsugu , Kawai Shunzo , Fukui Kenichi 
Published: April 2003

AbstractThe solid‐state polymerization of maleimide by 2,2′‐azobisisobutyronitrile was studied over the temperature range 65–85°C. The polymerization was carried out either by heating the solid mixture of maleimide and 2,2′‐azobisisobutyronitrile or by heating the two compounds separately in twin ampules. The results of the kinetic study showed that the lifetime of the propagating radicals was short and that the rate of termination was proportional to the mole amount of propagating radicals. The ESR spectrum showed that stable radicals that were not main propagating radicals were in the polymerizing system.
The composition of catalysts prepared from tri‐n‐propylaluminum, anisole, and titanium tetrachloride
Authors: Cunningham Robert E. , Dove Ray A. 
Published: April 2003

AbstractCatalysts were prepared from titanium tetrachloride and tri‐n‐propylaluminum or tri‐n‐propylaluminum anisole at [Al]/[Ti] molar ratios of 0.20–1.10. They were aged and filtered, and the solid and liquid portions were analyzed for aluminum, titanium, chlorine, and certain organic constituents. The analyses indicate that the solid of the nonetherate catalyst is predominantly TiCl3, some AlCl3 or aluminum alkyl chlorides being included. Only at [Al]/[Ti] = 1.10 was any alkyl group found in the solid. The same general results were found for the etherate catalyst, but the solid had a somewhat lower [Cl]/[Ti] ratio, indicating greater reduction or alkylation, or both, of the titanium species than in the nonetherate catalyst. The solid also contained some anisole at the higher [Al]/[Ti] ratios. The results lend general support to proposed reactions for the catalyst formation. The main differences in the etherate catalysts relative to the non‐etherate system, particularly at the higher [Al]/[Ti] ratios, are the apparently greater reduction or alkylation of the titanium in the solids, the presence of anisole in the liquid and solid portions, and the presence of phenol in the liquid portion. The phenol presumably comes from cleavage of the anisole during the catalyst formation. Not all of the anisole has been accounted for in a materials balance, nor has all of the chlorine in the etherate catalysts. No propyl or isopropyl chloride was found in the catalysts; there is no significant amount of polypropylene in any of the catalyst solids. Hence the fate of the alkyl groups remains undetermined at present.
Anionic polymerization and copolymerization of acrylophenone
Authors: Mulvaney J. E. , Dillon J. G. 
Published: April 2003

AbstractThe n‐butyllithium‐initiated polymerization of a mixture of acrylophenone (AP) and styrene produces only poly(AP), indicating that a chain ending in an AP enolate ion is not sufficiently nucleophilic to add to styrene. Radical copolymerization of AP and styrene yields a polymer containing 65% AP (at 41% conversion). In contrast, lithium dispersion‐initiated polymerization of AP and styrene produces a product containing 50–99% AP, depending upon conversion. This observation is discussed in terms of current knowledge concerning alkali metal‐initiated polymerization.
Polyaddition reaction of pseudoxazolones with dimercaptans
Authors: Iwakura Yoshio , Toda Fujio , Torii Yoshinori , Sekii Reiko 
Published: April 2003

AbstractPolymers having thioether, thiolester, and amide linkages in each repeating unit of a polymer main chain were prepared by the polyaddition reaction of pseudoxazolones (2‐isopropylidene‐4‐alkyl‐3‐oxazolin‐5‐ones) and dimercaptans. The polymers had inherent viscosities in a range of 0.08–0.22 and gave transparent films by solution casting.
Polymerization of cyclic iminoethers. V. 1,3‐oxazolines with hydroxy‐, acetoxy‐, and carboxymethyl‐alkyl groups in the 2 position and their polymers
Authors: Levy A. , Litt M. 
Published: April 2003

AbstractOxazolines containing carbomethoxy‐, acetoxy‐, and hydroxy‐alkyl groups on the side chain were prepared and polymerized. The properties of the polymers were investigated.
Polypyromellitimides: Details of pyrolysis
Authors: Gay F. P. , Berr C. E. 
Published: April 2003

AbstractPolyimide films from 4,4′‐diaminodiphenyl ether and pyromellitic dianhydride were pyrolyzed at 400–600°C. in non‐oxidative systems. Major gaseous products were carbon monoxide and carbon dioxide; hydrogen evolution occurred above 525°C. A mobile n‐imide‐isoimide equilibrium is in accord with the gas evolution data. Carbon dioxide arises from isoimide decomposition and carbon monoxide arises from the normal imide.
Charge transfer complexes of N‐ethylcarbazole and poly‐N‐vinylcarbazole
Authors: Rembaum A. , Hermann A. M. , Haack R. 
Published: April 2003

AbstractPoly‐N‐vinylcarbazole and its monomeric analog, i.e., N‐ethylcarbazole, act as donors in charge transfer complexes with such electron acceptors as iodine, tetracyanoethylene, and tetracyanoquinodimethane. Poly‐N‐vinylcarbazole and N‐ethylcarbazole are also capable of accepting electrons from an alkali metal such as sodium. A study of the spectral properties of both types of complexes showed that the monomer can both accept and donate electrons to a greater extent than the corresponding unit segment of the polymer chain. Equilibrium constants are presented for both cases, and estimates of the ionization potential of N‐ethylcarbazole and related compounds are made from the characteristic charge transfer frequencies. Good agreement between these values and those calculated from molecular orbital theory is outlined.
Metal coordination polymers. I. Synthesis and thermogravimetric analysis of beryllium phosphinate polymers
Authors: Slota P. J. , Freeman L. P. , Fetter N. R. 
Published: April 2003

AbstractThe preparation, properties, infrared, DTA, and TGA data are given for beryllium dimethyl‐, tetramethylene‐, di‐n‐butyl‐, di‐n‐pentyl‐, di‐n‐heptyl‐, methylphenyl‐, diphenyl‐, and bispentafluorophenylphosphinates. Synthesis of dimeric beryllium acetylacetonyl phenyl‐[o‐methylcarboranyl (B10)] phosphinate is reported. The beryllium phosphinates were prepared by the reaction of beryllium acetylacetonate with the appropriate phosphinic acid.