bluuebunny/crossref_metadata_2025 huggingface dataset:
Structure and reactivity in cationic polymerization of butadiene derivatives. IV. 1‐alkoxybutadienes
Authors: Otsuki Michihisa , Masuda Toshio , Higashimura Toshinobu
Published: April 2003

The reactivity of trans‐1‐alkoxybutadienes in cationic homopolymerization and copolymerizations and structure of the polymers produced were investigated. 1‐Ethoxybutadiene is polymerized easily at −78°C by various acidic catalysis. The reactivity of 1‐ethoxybutadiene was similar to that of ethyl vinyl ether. The polymers produced possessed molecular weights of several thousands, and were composed of 70–95% 1,4 structure and 5–30% 3,4 structure. In the copolymerization of ethyl vinyl ether (M1) with 1‐ethoxybutadiene at −78°C in toluene by boron trifluoride diethyl etherate, r1 = 1.15, r2 = 2.62. From the Hammett plot of the relative reactivities of alkoxybutadienes (alkoxy: CH3O, C2H5O, i‐C3H7O), the reaction constant p* was determined to be −2.9. Results of the present study were compared with those of various butadiene derivatives.
Morphology of organosilicon ladder polymers
Authors: Andrianov K. A. , Slonimsky G. L. , Zhdanov A. A. , Tsvankin D. Ya. , Levin V. Yu. , Papkov V. S. , Kvachev Yu. P. , Belavtseva E. M.
Published: April 2003

The morphology of organosilicon ladder polymers was studied by various methods, including x‐ray techniques, diffraction of monochromatic polarized light, and electron microscopy. The morphology is discussed as a function of the chemical composition, the molecular weight, and the method of preparation.
Syntheses of polymerizable hydroquinone derivatives
Authors: Kamogawa Hiroyoshi , Kitahora Kunimichi , Hanawa Hidehito , Nanasawa Masato
Published: April 2003

Several polymerizable hydroquinone derivatives were prepared by the Williamson synthesis. Thus, hydroquinone mono(p‐vinylbenzyl) ether (III‐1), hydroquinone methyl p‐vinylbenzyl ether (III‐4), and hydroquinone benzyl p‐vinylbenzyl ether (III‐5), tert‐butylhydroquinone mono(p‐vinylbenzyl) ether (III‐2), and 2,5‐di‐tert‐butylhydroquinone mono(p‐vinylbenzyl) ether (III‐3) were synthesized by the reactions of p‐chloromethylstyrene with the corresponding hydroquinone derivatives in alcoholic potassium hydroxide or with their potassium salts in dipolar aprotic solvents. All monomers were found to polymerize by free‐radical initiation except III‐3, which required a cationic initiator.
Polycondensation of mono‐ and difunctional derivatives of p‐xylene
Authors: Peppas Nikolaos A. , Valkanas George N. , Diamanti‐Kotsida Eugenia T.
Published: April 2003

A new method for the production of polydimethylbenzylenes,$ \rlap{--} [{\rm C}_6 {\rm H}_4 ({\rm CH})_2 {\rm CH}_{\rm 2} \rlap{--} ]_n $, involves the polycondensation of the mono‐ and dichloromethyl and mono‐ and diacetoxymethyl derivatives of p‐xylene via an acid‐catalyzed reaction in anhydrous acetic acid. The reaction of the difunctional derivatives is slower than the reaction of the monofunctional ones, leading to linear, predominantly crystalline, high‐melting polymers with molecular weights of 2000–3000. Polycondensation of both monomers under different feed ratios leads to polymers with the same structure, and the monofunctional monomers condense with themselves more favorably than with the difunctional ones. Thus a head‐to‐head structure is preferred, and crystalline polymers of high structural purity are obtained.
Polymer morphology and random chain scission
Authors: Jellinek H. H. G.
Published: April 2003

A theory has been developed for the kinetics of random chain scission of polymers consisting of amorphous and crystalline (spherulite) phases. The degrees of degradation have been derived for such scission due to a gas which in one case is able to penetrate spherulites where degradation is then diffusion‐controlled and in another case cannot diffuse into spherulites. In the later case, special conditions are prevalent in the amorphous–crystalline interface. Main‐chain links in crystalline fold regions are assumed to scission faster than all other main‐chain links due to strain energy.
Short branching in poly(vinyl alcohol). III. Some properties of model polymers of short‐branched poly(vinyl alcohol)
Authors: Morishima Y. , Irie Y. , Iimuro H. , Nozakura S.
Published: April 2003

Melting point, the iodine color reaction, and foam fractionation were studied on model poly(vinyl alcohol) (PVA) having short branches of one or two monomer units in length. An increase in the amount of short branching units caused a marked decrease in color intensity of the PVA–iodine reaction and in the melting point. These tendencies were more remarkable when the short branching was two monomer units in length than when it was one monomer unit. It was also found that foam fractionation of an aqueous PVA solution produced PVA fractions with different degree of short branching, the degree increasing with increase in the fraction number. The color intensity of the PVA–iodine reaction has been confirmed to decrease with increase in the fraction number, but this result cannot be explained solely in terms of the short branching. It is concluded that the phenomenon of foam fractionation of PVA and the iodine color reaction of the fraction appear to be governed by many factors such as molecular weight, stereoregularity, and short branching.
Short branching in poly(vinyl alcohol). IV. Determination of the short branches in poly(vinyl alcohol) polymerized under various conditions
Authors: Morishima Y. , Nozakura S.
Published: April 2003

The effect of the conditions of polymerization of vinyl acetate on the formation of short branching in the derived poly(vinyl alcohol) (PVA) was studied. 1H‐NMR combined with a CAT technique was employed for the determination of the short branches. It was found that the formation of short branching is favorable at low concentrations of monomer, at high conversions, and at high temperatures. These facts evidently support the idea that the mechanism of the formation of short branching is back‐biting. Amounts of short branches in some commercial PVA were also estimated. The observed values lie in the range of 0.12–1.7 mole‐%.
Solution properties of phosphonitrilic fluoroelastomers
Authors: Carlson D. W. , O'Rourke E. , Valaitis J. K. , Altenau A. G.
Published: April 2003

A series of phosphonitrilic fluoroelastomers which have excellent solvent resistance and low temperature flexibility, and which perform well under a broad range of service conditions, have been developed. The solution properties of one of these polymers were studied more extensively in order to develop suitable quality control procedures and to gain a better understanding of the polymer structure. Solvents for these procedures were established, fractionation procedures were developed, and intrinsic viscosity, osmotic pressure, and light‐scattering measurements were conducted. We found this polymer to have a very broad molecular weight distribution. And, although fractionation by molecular weight was effected, the fractions retained a broad molecular weight distribution. Our data do not indicate significant branching for this polymer. As a result of our studies, we have theorized that a supermolecular structure may be present in this polymer.
Effect of isotopic composition on free‐radical reactions in polyolefins
Authors: Milinchuk V. K. , Klinshpont E. R. , Vasilenko V. V.
Published: April 2003

On substitution of hydrogen by deuterium the radiation yield of free radicals in polyolefins decreases ca. 2‐fold. Under ultraviolet illumination (γ < 300 nm) in deuterated polyethylene (DPE), allyl radicals are converted into alkyl radicals (hfs constants a = 3.2 Oe, a = 4.4 Oe); in deuterated polypropylene (DPP), allyl and peroxide radicals are converted into alkyl radicals (a = 3.7 Oe). At 77°K under ultraviolet light in γ‐irradiated polyethylene (PE) and DPE, triene, tetraene, dienyl, trienyl, and tetraenyl radicals are formed. Deuterium substitution has no effect on absorption spectra of polyenyl radicals and polyenes. In polyolefins the quantum yields of photochemical reactions of allyl and peroxide radicals are 0.1–1.0. Photochemical reactions of peroxide radicals result in a radical concentration increase of ca. 3‐fold. In reactions of peroxide radicals in the dark, a kinetic isotope effect has been observed. Activation energies of substitution reactions of peroxide radicals are in PE, 9.3 ± 0.3 kcal/mole; in DPE, 10.2 ± 0.3 kcal/mole; in PP, 12.7 ± 0.4 kcal/mole; in DPP, 14 ± 0.5 kcal/mole. Possible mechanisms of the effect of polyolefin isotope composition on radical formation by high energy irradiation as well as on photochemical and dark reactions of free radicals are discussed. The effect of the energy released from phototransformations and radiationless deactivation of macroradicals on the migration of free valence is also considered.
Studies on the photooxidation mechanism of polymers. V. Oxidation of polybutadienes by singlet oxygen from microwave discharge and in dye‐photosensitized reactions
Authors: Rabek J. F. , Rånby B.
Published: April 2003

The singlet oxygen oxidation of cis‐ and trans‐ 1,4‐polybutadienes was studied by using singlet oxygen generated in a microwave generator and in dye‐photosensitized reactions of these polymers in the solid state and in solution. It was shown that the reactions of singlet oxygen result in formation of hydroperoxide groups, whereas ultraviolet oxidation by molecular oxygen in addition leads to formation of carbonyl groups. During dye‐photosensitized oxidation of polydienes in benzene solution, a very rapid decrease in the molecular weight was observed.
Polyimidines, a new class of polymers. I. Phenylated polypyromellitimidines
Authors: Cassidy Patrick E. , Syrinek Allen
Published: April 2003

Model compounds and polymers containing the imidine functional group have been synthesized from diphenylphthalide and tetraphenylpyromellitide by condensation with mono‐ and diamines. The diamine monomers included: 1,6‐diaminohexane, p‐phenylenediamine, and 4,4′‐diaminodiphenyl ether. Reactions were run either in biphenyl or with no solvent at 250–300°C to yield up to 57% product with molecular weights up to approximately 16,000 and inherent viscosities to 0.15. All polymers were soluble in chloroform and dimethylformamide and showed thermal stabilities by TGA to range from 225°C (for aliphatic backbones) to 400°C (for aromatic systems).
Anionic polymerization initiated by lithium diethylamide in organic solvents. III. Investigation of the polymerization of styrene
Authors: Hurley S. A. , Tait P. J. T.
Published: April 2003

The polymerization of styrene, initiated by lithium diethylamide in mixtures of benzene and THF, has been investigated. Kinetic and molecular weight measurements are interpreted on the basis of simultaneous initiation and propagation steps, and the effect of solvation and coordination processes on these reactions is discussed. Initiation of polymerization is thought to involve addition of solvated lithium diethylamide ion‐airs to styrene, giving species with diethylamide end groups. The possible influence of these end groups on the initiation is considered in terms of an intramolecular cyclization process. Propagation of polymerization is believed to involve polystyryllithium ion‐pairs, solvated to varying extents by THF. No evidence has been found to suggest that chain transfer, or termination, reactions are an integral part of the polymerization process. The polymerization has a number of similarities to the alkyllithium‐initiated polymerization of styrene, but also exhibits some interesting differences.
Effect of chemical structure and thermal history on the β transition of polystyrene and some substituted polystyrenes
Authors: Bach Van Nguyen , Noel C.
Published: April 2003

DTA (differential thermal analysis) traces for various kinds of polystyrene and substituted polystyrenes, including bulk‐polymerized, monodisperse, and isotactic samples, have been recorded below the glass temperature. It has been shown that the β transition is dependent upon polymer structural modification, traces of water or solvent, and sample thermal history. The experimental data presented here support the conclusion that the β transition is due to conformational changes involving backbone motions and phenyl ring reorientation.
Aromatic polyethers, polysulfones, and polyketones as laminating resins. VIII. Aryl disulfide units as crosslinking agents
Authors: Wong Daniel Ting‐Man , Marvel C. S.
Published: April 2003

Oxidation of 1,4‐phenylenedimercaptan has given a cyclic trimeric disulfide. Oxidation of 1,3‐phenylenedimercaptan has yielded a similar product. These monomers have been incorporated in the chains of aromatic polyether, sulfone, ketone polymers and serve as crosslinking sites on heating these polymers.
Mechanisms of inhibition against the copper‐catalyzed oxidation of polyethylene: Structures and catalytic reactivities of copper–inhibitor complexes
Authors: Allara D. L. , Chan M. G.
Published: April 2003

A series of compounds, mostly derivatives of N,N′‐diphenyloxamide, used as inhibitors of copper‐catalyzed oxidation in polyolefins has been reacted with cupric salts. The resultant copper–inhibitor complexes have been characterized as insoluble, polymeric solids, and their catalytic reactivities in the oxidation of low‐density polyethylene were measured at 100°C. The maximum rates of oxidation are first‐order in surface area, and some very general trends in structure and reactivity can be drawn from these data. Reasons for the relative effectiveness of various copper deactivators in polyolefin oxidation are briefly discussed.
Interaction of poly(vinylpyrrolidone) with p‐substituted phenols in aqueous solution
Authors: Inoue Masami , Otsu Takayuki
Published: April 2003

The interaction of poly(vinylpyrrolidone) (PVP) with various p‐X‐substituted phenols (X = CH3O, CH3, C2H5, H, Cl, Br, and NO2) in aqueous solution was investigated by means of equilibrium dialysis at 30°C. By applying the Klotz equation for the results obtained, the bonding constants K between PVP and p‐substituted phenols were determined. It was found that the K values were approximately correlated with the Hammett σ values of p‐substituents in phenols, indicating that the bonding forces due to electrostatic and hydrogen‐bonding interactions were significant, and they increased with increasing electron‐withdrawing nature of the substituents. Therefore, in addition to the hydrophobic interaction which has been accepted, it was assumed that the above interaction forces also played an important role in the interactions between PVP and p‐substituted phenols in aqueous solution.
Molecular weight analysis of pitches and polymeric pitches by gel‐permeation chromatography
Authors: Lewis I. C. , Petro B. A.
Published: April 2003

The technique of gel‐permeation chromatography (GPC) has been developed as a method for measuring molecular weight distribution in pitch materials. Molecular weight calibration data were obtained from measurements made on GPC fractions collected from a standard pitch. By solubilization of the polymeric portion of pitch through a reduction with lithium in ethylenediamine, the molecular weight range for analysis was extended to in excess of 3000. Mass spectroscopy has been used to further analyze some of the GPC fractions. The GPC calibration data can be employed, with the aid of computer analysis, to determine quantitatively number‐average molecular weights M̄n weight‐average molecular weights M̄w, and molecular weight distribution D (= M̄w/M̄n) in pitch materials.
Conductance studies of salt solutions in the presence of poly(vinylbenzo crown ethers)
Authors: Shah S. C. , Kopolow S. , Smid J.
Published: April 2003

The conductance of acetone and methyl ethyl ketone solutions of tetraphenylborate salts in the presence of homopolymers and styrene copolymers of vinylbenzo‐15‐crown‐5 and vinylbenzo‐18‐crown‐6 was studied, and the results compared with data obtained for crown ethers. Polycations are formed on binding cations to the poly(crown ethers), and the conductance behavior of the polyelectrolytes depends on the nature of the cation‐crown complex and the spacing between crown moieties which in turn determines the charge density on the polymer chain. The compositions of the crown‐cation complexes were determined for crown ethers. The complex formation constants of sodium and potassium cations to poly(vinylbenzo‐18‐crown‐6) were found to change as more cations bind to the chain. This is not the case for the copolymers where the crown ligands are spaced farther apart. A mixture of poly(vinylbenzo‐15‐crown‐5) and 10−3M potassium tetraphenylborate in methyl ethyl ketone or acetone has a minimum conductance at a crown to cation ratio of 3.0, but the conductance rapidly increases on addition of crown ether. This was used to qualitatively determine the binding efficiency of a series of crown ethers since the rate of increase in the conductance is a measure of the binding ability of the crown ether to the cation.
Emulsifier‐free emulsion polymerization with ionic comonomer
Authors: Juang Mike Shi‐Der , Krieger Irvin M.
Published: April 2003

Emulsion polymerization of styrene in the absence of emulsifier with K2S2O8 as initiator produced uniform latices. Incorporation of ca. 0.5% ionic comonomer (sodium styrenesulfonate) reduced the particle size from the range 0.5–1.0 μm achieved in prior emulsifier free formulations to a range of 0.15–0.40 μm. Some advantages achieved by incorporation of ionic comonomer were higher polymer content and independently controllable surface charge density. Particle diameter varied as the 0.64 power of the ratio of ionic strength to comonomer, as the −0.20 power of initiator concentration, and as the 0.46 power of monomer content. Kinetic data suggest that copolymerization takes place in the aqueous phase, and that nuclei for particle growth are formed by precipitation of the initially water‐soluble copolymer. The latex is stabilized by sulfonic acid groups of the comonomer, as well as by sulfate end groups from the initiator.
Hydroxamic acid polymers. II. Design of a polymeric chelating agent for iron
Authors: Winston Anthony , McLaughlin Glenn R.
Published: April 2003

The iron chelating ability of hydroxamic acid polymers was studied as a function of the atomic chain spacing separating neighboring hydroxamic acid units. Two polymers were prepared, one having the hydroxamic acid group separated by 11 atoms and the other by three atoms. The iron binding of these polymers was compared with the model compound desferrioxamine B (DFO) and with a previously prepared polymer having a nine‐atom spacing. Mole ratio plots indicated the following order of stability: DFO ≈ 11 atom > 9 atom > 3 atom. These results are in accordance with the picture derived from molecular models which shows that with a spacing of 11 atoms, three neighboring hydroxamic acids can fit the octahedral arrangement of the iron (III) complex without appreciable strain. Some strain is introduced when the spacing becomes only nine atoms, and with three atoms, complex formation between three neighboring groups becomes virtually impossible.
Study of radiation‐induced polymerization of vinyl monomers adsorbed on inorganic substances. VIII. Polymerization of styrene and methyl methacrylate adsorbed on aerosil
Authors: Fukano Kazuyuki , Kageyama Eiichi
Published: April 2003

Aerosil is silica having a purity which is very high compared with that of silica gel and having, unlike silica gel, no micropores. To investigate the effects of impurities and micropores on the radiation‐induced polymerization of styrene and methyl methacrylate adsorbed on silica gel, the radiation‐induced polymerization of styrene and methyl methacrylate adsorbed on Aerosil was carried out. The results of both the styrene–Aerosil 300 system and the methyl methacrylate–Aerosil 300 system were similar to those of the styrene–silica gel and methyl methacrylate–silica gel systems, respectively. This suggests that in the radiation‐induced polymerization of both styrene–silica gel and methyl methacrylate–silica gel systems the impurity and the presence of micropores have almost no effects on the reaction mechanism. The effect of aluminum as an impurity was investigated on the styrene–Aerosil MOX 170 system. It was found that aluminum accelerated the cationic polymerization.
Study of radiation‐induced polymerization of vinyl monomers adsorbed on inorganic substances. IX. Preirradiation polymerization of styrene–silica gel system
Authors: Fukano Kazuyuki , Kageyama Eiichi
Published: April 2003

Preirradiation polymerization of the styrene–silica gel system was studied in detail. Both graft polymers and homopolymers have bimodal GPC spectra. High molecular weight peaks were formed in a radical mechanism and the low molecular weight peaks were formed in a cationic mechanism as same as those in the simultaneous irradiation polymerization. The rate of formation of the low molecular weight peaks was very high compared with that of the high molecular weight peaks. Monomer conversion and percent grafting leveled off at about 1–2 Mrad. Radiation dose dependence of the four peaks were different from each other. Monomer conversion and percent grafting decreased as the preheating temperature of silica gel increased. The amount of the low molecular weight peaks of graft polymers depended on the number of silanol groups, as in the case of the simultaneous irradiation polymerization. A reaction mechanism for the preirradiation polymerization is proposed based on the results obtained.
Radiation‐induced emulsion copolymerization of tetrafluoroethylene with propylene. VI. Effects of pressure and temperature
Authors: Matsuda Osamu , Okamoto Jiro , Tabata Yoneho , Machi Sueo
Published: April 2003

In a radiation‐induced emulsion copolymerization of tetrafluoroethylene with propylene, the effects of pressure and temperature were investigated in the range of 0–40 kg/cm2 and 7–53°C at emulsifier concentration of 0.5 and 2.0%. Both the polymerization rate and the molecular weight of copolymer increase with increasing pressure and decreasing temperature. These facts are mainly due to an increase of the monomer concentration in the polymer particles. The rate of polymer chain formation was found to be independent of pressure and temperature. The initiation reaction is due mainly to the entry of radicals generated in the aqueous phase into the polymer particles. The apparent activation energy is −2.0 to −3.8 kcal/mole for the polymerization in the presence of 0.5% emulsifier, but is nearly zero at an emulsifier concentration of 2.0%. This difference in apparent activation energies at emulsifier concentrations of 0.5 and 2.0% is explained in terms of the termination mechanisms.
Formation of crystalline polyelectrolytic complexes on matrix polymerization
Authors: Kabanov V. A. , Kargina O. V. , Ulyanova M. V.
Published: April 2003

Zwitterionic matrix stepwise polymerization of 4‐vinylpyridine (VP) using isotactic poly(acrylic acid) (i‐PAA) as a template results in formation of crystalline polycomplexes consisting of i‐PAA and of ionene (I):
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Depending on the concentration of VP and i‐PAA, the two types of crystalline polycomplexes can be prepared. The complex containing long ionene sequences with n ≫ 2 is formed when [VP]0 = [i‐PAA]0 ≥ 0.05M. At [VP]0 = [i‐PAA]0 ⩽ 0.01M, the complex formed evidently contains the ionene dimer (n = 2). The x‐ray structures of the crystalline complexes are identical with those obtained by mixing of i‐PAA and the corresponding dimer and polymer presynthesized in the absence of the template. The matrix polymerization of VP in the presence of syndiotactic and atactic PAA at the same conditions results in formation of amorphous polycomplexes.
Preparation and heat of polymerization of 3‐methyl‐3‐butyl‐2‐azetidinone
Authors: Šebenda J. , Hauer J. , Biroš J.
Published: April 2003

The synthesis of 3‐methyl‐3‐butyl‐2‐azetidinone, which forms a polymer which is soluble in a number of common solvents including toluene, chloroform, and carbon tetrachloride, is described. Anionic polymerization, carried out in toluene solution in a calorimetric vessel, yielded for the heat of polymerization of a four‐membered lactam −19.1 kcal/mole at 25°C.
Kinetics of radiation‐induced grafting reactions. III. Poly(isobutylene oxide)—styrene systems
Authors: Omichi Hideki , Araki Kunio , Takahashi Thoru , Yasukawa Tamio , Murakami Kenkichi
Published: April 2003

Graft polymerization of styrene onto preirradiated poly(isobutylene oxide) was carried out at 25°C. The concentration of active sites for grafting was estimated by means of ESR and by the activation analysis of bromine atoms bound to the chain ends. Kinetic data such as differential amount of active sites (DACT), growth rate (GR), and average lifetime (τ) were obtained to calculate the molecular weight distribution of graft chains by the Monte Carlo simulation method. The number‐average molecular weight of the graft chain was calculated from the equation, Mn = 2GRτ (mw), which agreed well with the observed value.
Direct synthesis and properties of polybenzodipyrrolediones from dibenzylidenebenzodifurandiones and various diamines
Authors: Imai Yoshio , Ueda Mitsuru , Takahashi Takeyoshi
Published: April 2003

Aromatic and aliphatic polybenzodipyrrolediones have been synthesized directly by the solution cyclopolycondensation of two dibenzylidenebenzodifurandiones with four different diamines in refluxing m‐cresol or o‐phenylphenol in the presence of boric acid. The polymerizations proceeded smoothly in a homogeneous solution and afforded the heterocyclic polymers having inherent viscosities as high as 1.0 almost quantitatively. All the polymers were readily soluble in a wide range of solvents, including N‐methyl‐2‐pyrrolidone (NMP), hot m‐cresol, and hot pyridine. Tough, transparent, yellow films could be cast from NMP solutions of the polymers. Thermogravimetric analysis of the aromatic polybenzodipyrrolediones showed a 10% weight loss temperature of 460–500°C under nitrogen. The results also indicated that the aromatic polymers were somewhat less thermally stable than wholly aromatic polypyromellitimides.
Crystalline copolyamides of β‐(4‐aminophenyl)‐propionic acid and caprolactam
Authors: Shalaby S. W. , Turi E. A. , Harget P. J.
Published: April 2003

Methyl β‐(4‐aminophenyl)propionate was prepared and converted to a crystalline polyamide. The copolymerization of β‐(4‐aminophenyl)propionic acid or its methyl esters with caprolactam resulted in polyamides having wide ranges of crystallinity and thermal stability, depending on the chemical composition. Copolymers with 10, 50, 85, 90, and 95 mole‐% of caproamide sequences were shown by x‐ray and differential scanning calorimetry to be semicrystalline. The composition and thermal stability of the polyamides were studied by infrared spectroscopy and thermogravimetric analysis, respectively.
Functionality and structure of polymers. I. Photoreaction and fluorescence of polyesters having pendant anthryl groups
Authors: Tazuke Shigeo , Banba Fumio
Published: April 2003

Various polyesters having pendant (9‐anthryl)methyl groups were prepared from 2‐(9‐anthryl)methylpropane‐1,3‐diol and the esters or chlorides of dicarboxylic acids. These polyesters are poly[2‐(9‐anthryl)‐methylpropane‐1,3‐diyl‐oxy‐(9‐anthryl)methylmalonyl‐oxy](PA‐1A), poly‐[2‐9‐anthrylmethylpropane‐1,3‐diyl‐oxysuccinyloxy](PA‐2), poly‐[2‐9‐anthrylmethylpropane‐1,3‐diyl‐oxyadipyloxy](PA‐4), poly[2‐(9‐anthryl)methylpropane‐1,3‐diyl‐oxysebacyloxy] (PA‐8), poly[2‐(9‐anthryl)methylpropane‐1,3‐diyl‐oxy‐(1‐naphthyl)methylmalonyloxy](PA‐1N), and poly[2‐(9‐anthryl)methylpropane‐1,3‐diyl‐oxyterephthaloyloxy](PA‐Ph). Although the absorption spectrum of the anthryl group is not influenced by the change in the environment in which the anthryl group is located, the fluorescence spectra show characteristic change reflecting the environment around the chromophore. Dimer, aggregates, or excimer fluorescence of anthryl groups and energy transfer from naphthyl to anthryl groups for PA‐1N were discussed. The rates of photodimerization of anthryl groups determined spectroscopically in dilute solutions for these polyesters and their monomer model compound(1,3‐diacetoxy‐2(9‐anthryl)methylpropane) (MA), were in the following order; PA‐8 > PA‐4 > PA‐1A > PA‐2 > PA‐Ph > MA. The effects of polymer structure on the photoreaction were discussed on the basis of information on molecular interactions obtained by fluorescence spectroscopy. The fraction of intramolecular cyclization was estimated from dependence of the rate of photoreaction on the concentration of the polyesters. When anthryl groups are linked by a long, flexible polymethylene chain (PA‐8), intramolecular process predominates whereas intermolecular dimerization proceeds almost exclusively for a rodlike molecule(PA‐Ph). These results are discussed from the viewpoint of the structure–functionality relationship in polymeric systems.
Investigation of structural changes in wool fibers due to annealing
Authors: Shishoo Roshan , Lundell Malte
Published: April 2003

Structural changes in wool fibers after annealing, i.e., storage at 45°C and 80% RH, have been investigated by using the method of laser Raman spectroscopy and by measuring birefringence and density of wool. The results show that CH2 groups in wool give parallel Raman dichroism which increases very significantly after annealing. No increase in birefringence and density occurred after annealing. A hypothesis has been put forward which states that for minimum energy considerations in wool fibers the existence of intrahelix crosslinks other than hydrogen bonds is important. It is highly probable that a large number of electrovalent intrahelix crosslinkages exist between the suitable side groups on the main polypeptide chain in the α‐helix of annealed wool.
Polymerization of propylene with TiCl3–AlEt2Cl–polymeric electron donor catalyst
Authors: Shikata Kazuo , Osawa Hisakazu , Kida Yasuji
Published: April 2003

Polymeric donors having ether or carbonyl groups were added to the TiCI3–AlEt2CI catalyst system as the third component, and the effects on the polymerization of propylene were investigated in comparison with the effect of the electron donors with low molecular weight. The polymeric donors were effective in making the catalyst more active, but the donors of low molecular weight depressed the catalyst activity. In the case of poly(propylene glycol dimethyl ether) (PPG‐DME), PPG–DME with a number of propylene oxide units (n) of more than 6.7 was effective in enhancing the catalyst activity. These effects were considered to be due to the different reactivities between TiCI3 and AlEt2CI‐polymeric donor complexes having various chain lengths.
Synthesis of oligoesters from oxalic acid and glycerol
Authors: Alksnis A. F. , Gruziń I. V. , Surna Ya. A.
Published: April 2003

A new synthesis for the polycondensation of oxalic acid and glycerol was used. Polycondensation was carried out in the presence of compounds that do not dissolve oxalic acid and glycerol, but form an azeotropic mixture with water below 100°C. Anhydrous oxalic acid and oxalic acid dihydrate was used for the synthesis of oligoesters. The decarboxylation proceeds parallel with polycondensation of oxalic acid and glycerol was investigated. Decarboxylation of carboxyl groups of glycerol monooxalate was found to be accelerated by the arrangement of primary and secondary hydroxyl groups in the glycerol molecule in the 1,2 position.
Chloroaromatic ether amines
Authors: Kwiatkowski G. T. , Brode G. L. , Bedwin A. W.
Published: April 2003

A new and useful class of aromatic amines, based on multichlorinated benzenes and polyphenyls, has been developed. The amines are prepared by reacting the alkali metal salt of p‐aminophenol with the chloroaromatics under nucleophilic substitution reaction conditions. Oligomeric amines can be obtained by condensing, e.g., the dialkali salt of bisphenol A and the alkali metal salt of p‐aminophenol with the chloroaromatics. The products are mixtures of mono‐, di‐, and triamines, as a result of the complex functionalities of the chloroaromatics employed. Unique features of the amines include: (1) flame‐retarding characteristics; (2) markedly reduced amine reactivity (compared with aniline); (3) thermal stability; (4) good solubility in the usual organic solvents.
Polycondensation of pyridine‐2,6‐dicarboxylic acid with some di‐ and tetraamino compounds
Authors: Banihashemi A. , Eghbali M.
Published: April 2003

Pyridine‐2,6‐dicarboxylic acid phenyl ester was condensed with 3,3′‐diaminobenzidine and 3,3′,4,4′‐tetraaminodiphenyl ether. Polyamides were also synthesized by condensation of the above ester with p‐phenylenediamine, benzidine, 4,4′‐diaminodiphenyl sulfide and 4,4′‐diaminodiphenyl sulfone. These amides had higher inherent viscosities and greater thermal stability than was reported before. Model compounds of imidazoles were prepared by condensation of the same ester with o‐phenylenediamine and 2,3‐diaminopyridine and of polyamides by condensation with aniline and 2‐aminopyridine. In the case of the polyimidazole, the completely closed ring of imidazole did not form. The ultraviolet spectra of model compounds were compared with those of the polymers. The thermogravimetric curves show that the polymers are stable up to more than 400°C under argon atmosphere. All polymers were insoluble in most organic and inorganic solvents. They dissolved only partially in DMSO and DMF. Inherent viscosity was measured for the soluble polymer fraction.
Polymerization of allyl phenyl ether
Authors: Hui K. M. , Yip L. C.
Published: April 2003

Allyl phenyl ether polymerized rapidly and quantitatively to a resin with a structure similar to a phenolic thermoset in the presence of boron trifluoride etherate at 50°C. The structure and properties of this polyphenol were studied. A reaction mechanism involving rearrangement was discussed.
Linear polybenzyls. II. Lack of structure control in benzyl chloride polymerization
Authors: Kuo Jeffrey , Lenz Robert W.
Published: April 2003

Polybenzyls were prepared from benzyl chloride with different catalysts and solvents and at different temperatures. A model compound reaction for the polymerization was studied by reacting benzyl chloride with an excess amount of diphenylmethane to determine the effect of reaction conditions on substitution distribution. The degree of branching of polybenzyl samples was characterized from the infrared absorption spectra by using peaks assigned to para and ortho disubstitution products and monosubstitution units. The degree of branching so obtained correlated well with the results from the model compound reactions and with the thermal stabilities of the polymers. Anthracene unit formation was also related to the isomer content, and addition of complexing agents such as SO2 or tetranitromethane caused a reduction in branching during polymerization. An unusual glass transition behavior was observed in these polymers.
Transition metal complexes of poly(vinylpyridines)
Authors: Agnew N. H.
Published: April 2003

The structures of the precipitates of free‐radical poly(4‐vinylpyridine) (Vpy), free‐radical poly(2‐Vpy) and isotactic poly(2‐Vpy) with M(II)Cl2 (M = Co, Ni, Cu, Zn) obtained from solution have been investigated. The polymer compounds are similar to the known crystalline monomeric Vpy complexes and, with one exception, are crosslinked by the metal dichloride. Co(II) and Zn(II) are tetrahedrally coordinated by the polymer, while the Ni(II) and Cu(II) complexes are probably tetrahedral and square‐planar, respectively. Because of the constraints of the polymeric ligands the stoichiometries of the complexes are not exactly the same as those of the monomeric Vpy complexes and from one to two Vpy units per metal halide are on average not coordinated. Atactic and isotactic poly(2‐Vpy) showed marked differences with regard to coordination of Ni(II). The questions of stereochemistry of the coordinated metal ion, stoichiometry of the complexes, intermolecular versus intramolecular complexation of the polymer chain, and the influence of polymer tacticity on the crystallizability of polymer complexes are discussed.
Use of model compounds to determine equilibrium melting points of polymers
Authors: Hay James N.
Published: April 2003

Evidence is given for the relationship

describing the approximate dependence of the observed melting points Tm of oligomers on their degree of polymerization n, and its use in determining the equilibrium melting point T°m of the extended chain crystal and the heat of fusion Δh. Polyethylene and the n‐alkanes, poly(ethylene oxide) and poly(methylene oxide), polyphenylene and other systems are considered.
Relaxation processes in mixtures of polymers with linear amides
Authors: Kotlík P. , Heidingsfeld V. , Zelinger J. , Červinka O.
Published: April 2003

Results of dynamic measurements of mixtures of polymer with linear low molecular amides are presented. New secondary relaxation processes that were revealed were elucidated by conformation motions of the amide group of low molecular compounds. The effect of water and similar substances on the character of low‐temperature relaxation processes is also discussed.
Grafting of styrene onto low molecular weight polymers and copolymers of butadiene
Authors: Gasperowicz Aleksandra , Łaskawski Włodzimierz
Published: April 2003

The grafting of styrene onto low molecular weight polybutadienes and butadiene–styrene co‐polymers was studied. A mathematical method was used for the design of experiments and for the determination of the optimum grafting conditions with respect to the conversion of styrene and the efficiency of grafting. The reaction parameters were temperature (65–105°C), time (2–10 hr), concentration of the initiator, polymer to monomer ratio (10/90–90/10) and dilution by solvent (toluene). The optimum grafting conditions were chosen under which 50–60 wt‐% of styrene was grafted onto backbone polymer at a high conversion of the monomer. It was found that the reactions producing graft copolymer prevailed over the styrene homopolymerization when the temperatures employed were lower (65–85°C), and the reaction time (8–10 hr), backbone polymer/monomer ratio, and the dilution by solvent were higher. The efficiency, density, and degree of grafting were found to increase with the increase in the molecular weight of the backbone polymer. The efficiencies and densities of grafting onto low molecular weight polybutedienes were higher than those of grafting onto low molecular weight butadiene–styrene copolymers. Grafting efficiencies and grafting densities were in the ranges 37.8–61.6 wt % and 0.06–0.26, respectively, in the studied range of number‐average molecular weights (M̄n = 2400–6000).
Kinetic approach to radiation‐induced grafting in the polyethylene–styrene system. II
Authors: Imai Masahiko
Published: April 2003

The investigation method reported in the previous paper was applied to four reaction methods: preirradiation method with reaction in liquid monomer, preirradiation method with reaction in monomer vapor, simultaneous irradiation method in liquid, and simultaneous irradiation method in vapor. The increasing patterns and values of the degree of grafting experimentally obtained roughly agreed with those calculated by using the same rate constants. At high monomer concentration, the rate of grafting was small; at low monomer concentration, the rate of grafting was large. Strictly speaking, the data by simultaneous irradiation method were somewhat larger than those by calculation. Two additional factors, as homopolymerization and the grafting from the radicals formed on the grafted polystyrene, were considered and discussed. The rate constants obtained were also discussed.
Thiourea–potassium bromate redox system‐initiated graft polymerization of methyl methacrylate and methacrylic acid on nylon 6
Authors: Hebeish A. , El‐Rafie M. H. , Waly A. I.
Published: April 2003

The ability of thiourea–potassium bromate redox system to initiate graft polymerization of methyl methacrylate (MMA) and methacrylic acid (MAA) onto nylon 6 was investigated under a variety of conditions. With both monomers, increasing potassium bromate concentration up to 20 mmole/l. caused a significant enhancement in the graft yield. Above this concentration, the latter nearly leveled off in the case of MAA and decreased in the case of MMA. The effect of increasing thiourea concentration up to 15 mmole/l. was to bring about an outstanding increase in the graft yield. Above this concentration grafting decreased sharply. The grafting yield increased as the reaction time increased, then leveled off. The rate of reaction is temperature‐dependent. Within the range studied, the rate of grafting follows the order 70 > 60 > 50°C. Nylon samples grafted with MAA showed higher moisture regain than the ungrafted nylon. The increment in moisture regain depends on the percent graft yield.
Thermal degradation of poly(bismaleimides)
Authors: Stenzenberger H. D. , Heinen K. U. , Hummel D. O.
Published: April 2003

Thermal decomposition of poly(bismaleimides) has been investigated by using programmed and isothermal thermogravimetric analysis (TGA) in nitrogen. Reaction rates and overall activation energies were calculated from isothermal weight less studies. For five aliphatic poly(bismaleimides) a linear correlation between the activation energies and the number of methylene groups in the sequence between the maleimide residues was found. Aliphatic poly(bismaleimides) follow first‐order kinetic law up to a conversion of 60‐70% having activation energies between 196 and 256 kj/mole. poly(2,4‐bismaleimidotoluene) which was found to have in highest polymer decomposition temperature (PDT) did follow the first‐order kinetics up to a conversion of 60% in contrast to other aromatic poly(bismaleimides). In addition to the TGA, the pyro‐field ion mass spectra of the polymers were recorded and are discussed.
Polymerization of 5‐(1‐adamantyloxy)‐2H‐pyrrole‐2‐one
Authors: Wilson John C.
Published: April 2003

5‐(1‐Adamantyloxy)‐2H‐pyrrole‐2 one has been homopolymerized and copolymerized with a variety of comonomers. Polymerization was conducted in chloroform solutions with α,α′‐azobisisobutyronitrile initiator. Evidence of polymerization was achieved through infrared and NMR spectra and elemental analysis. Moderate molecular weights were achieved as determined by inherent viscosity measurements and gel‐permeation chromatography. Photolysis of the polymers with ultraviolet radiation induces a photochemical rearrangement resulting in the formation of isocyanate functions. A proposed mechanism suggests α‐cleavage of the carbonyl to give a 1,5‐diradical which rearranges to a 1,3‐diradical with subsequent ring closure to give a polymer with cyclopropyl isocyanate moieties in the backbone. DSC data show all polymers to display intense exothermic activity at temperatures near 200°C on initial heating and glass transition temperatures between 194 and 245.5°C on subsequent heating. Thermolysis of the homopolymer causes rearrangement to poly[N‐(1‐adamantyl) maleimide]. Reactivity ratios were determined for the systems styrene (M1) and 5‐(1‐adamantyloxy)‐2H‐pyrrole‐2‐one (M2) (r1 = 0.06, r2 = 0.07) and methyl methacrylate (M1) and 5‐(1‐adamantyloxy)‐2H‐pyrrole‐2‐one(M2) (r1 = 0.35, r2 = 0.70). Q and e values for 5‐(1‐adamantyloxy)‐2H‐pyrrole‐2‐one are 3.40 and 1.59, respectively.
Influence of rigid polymer matrices on the reversible photochemical reaction of α‐p‐dimethylaminophenyl‐N‐m‐nitrophenylnitrone
Authors: Smets G. J. , Matsumcto S.
Published: April 2003

The thermally reversible photocyclization of α‐p‐dimethylaminophenyl‐N‐m‐nitrophenylnitrone (I) to the corresponding oxaziridine (II) was studied in solution and in rigid polymer matrices. Irradiation with light of wavelength above 380 nm causes a clean transformation of (I) to (II) in solution as well as in polymer matrices. The quantum yield of the photoreaction in solution is about 0.06, the value being almost independent of the nature of the solvent and the irradiation time. In poly‐(methyl methacrylate) (PMMA) and in polystyrene (PSt) films, the photocyclization shows initial quantum yields of 0.1 and 0.23, respectively, which decrease with irradiation time. In solution in the dark, II reverted mainly to I with formation of side product(s) in a first‐order reaction. The recovery of I during the dark reaction (60–90%) as well as the rate constant of the reaction are strongly affected by the solvent. The kinetics of the thermal return in the two polymer matrices does not follow the first‐order rate law. The initial reaction rate as well as the extent of the recovery of I in PMMA film are greater than those in ethyl acetate.
Higher aliphatic polyaldehydes. IV. Transitions in poly(n‐valeraldehyde), poly(n‐hexaldehyde), poly(n‐heptaldehyde), and poly(n‐octaldehyde)
Authors: Negulescu I. , Vogl O.
Published: April 2003

Crystalline polymers of n‐valeraldehyde, n‐hexaldehyde, n‐heptaldehyde, and n‐octaldehyde were prepared by anionic polymerization with lithium tertiary butoxide as the initiator at low temperatures. The polymers were end‐capped with acetic anhydride, and their thermal stability was studied primarily by DTG. It was found that all polymers degrade rapidly above 150°C. All polymers show a dual melting‐point behavior. The first melting region, which is associated with the melting of the side chain, is 80–85°C for poly(n‐valeraldehyde); 87–90°C for poly(n‐hexaldehyde); 78–101°C for poly(n‐heptaldehyde); and 41–69°C for poly(n‐octaldehyde). Annealing and quenching of the samples showed that this melting‐point region consisted of several endotherm peaks whose intensity changed according to the thermal history of the sample. Although the samples are apparently highly crystalline, the side‐chain crystallinity is apparently only in the 20% range.
Study of the direct detection of crosslinks in hydrocarbons by 13C‐NMR. I. Preparation and characterization of model compound 1,1,2,2‐tetra(tridecyl) ethane
Authors: Bennett R. L. , Keller A. , Stejny J.
Published: April 2003

The present series of papers is the commencement of a study aimed at the direct detection and quantification of crosslinking in hydrocarbons with the ultimate objective of a precise study of radiation‐induced crosslinking in polyethylene. The subject of the present paper is the synthesis of a model compound containing a crosslink in a well‐defined position sufficiently remote from the chain ends to be representative of an average crosslink in polyethylene. Such a compound in the form of 1,1,2,2‐tetra(tridecyl) ethane has been synthetized and isolated in pure form in the course of the present work. Melting points and x‐ray spacings of the new compound have been determined, and a comparison with the corresponding linear paraffins has been made. Effects are noted relating to the influence of molecular shape on the GPC elution volume, in which context an observation on a cyclic paraffin is also quoted.
Study of the direct detection of crosslinking in hydrocarbons by 13C‐NMR. II. Identification of crosslink in model compound and application to irradiated paraffins
Authors: Bennett R. L. , Keller A. , Stejny J. , Murray M.
Published: April 2003

A 13C‐NMR investigation was carried out in aid of direct detection of crosslinks in hydrocarbons with the future objective of studying radiation‐induced crosslinking in polyethylene by a direct method. The resonance signal due to a tertiary carbon atom appropriate to a crosslink far remote from molecular ends has been identified in a definitive manner with the aid of the H‐shaped model compound 1,1,2,2‐tetra(tridecyl)ethane synthetized in Part I of this study. This identification was then put to use in the examination of the irradiated linear paraffins n‐hexadecane and n‐eicosane, where it enabled the detection of radiation‐induced crosslinks. This crosslinking could then be associated with corresponding changes in molecular weight (dimer, trimer formation) as revealed by discrete peaks in the gel‐permeation chromatograms of the same samples and randomness of the crosslinking process in the liquid state of these compounds being inferred.