bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of intrachain interactions on the kinetics of styrene polymerization and copolymerization
Authors: O'Driscoll K. F. , Wertz William , Husar Anna
Published: April 2003

In the free‐radical polymerization of styrene, it has been observed that the onset of an acceleration of the polymerization due to increased solution viscosity can be quantitatively measured as occurring at a critical point. The product of the degree of polymerization of the polymer in solution at the critical point times its volume fraction can be represented by a temperature‐dependent constant (P̄n, Vc, = K ). The value of the constant passes through a maximum between 60 and 90°C. The value of the constant is somewhat lower than that for the phenomenon called chain entanglement. It is postulated that the temperature‐dependent behavior of K is due to a previously reported solution phase transition which is believed to be caused by interaction between phenylgroups on the polystyrene chain. Observations on the ultraviolet absorbance of styrene copolymers and calculations on the absolute rate of copolymerization of styrene with methyl methacrylate are presented to support the postulated intrachain interactions.
Isomerization polymerization of 2‐vinyl‐1,3‐dioxolane by α,α′‐azobisisobutyronitrile or by γ‐ray irradiation
Authors: Kagiya Tsutomu , Nakayama Takeo , Nakai Yoshio , Fukui Kenichi
Published: April 2003

2‐Vinyl‐1,3‐dioxolane was polymerized by use of α,α′‐azobisisobutyronitrile (AIBN) or by γ‐ray irradiation. The polymer obtained was white amorphous powder which melted at ca. 70°C. and was soluble in chloroform, acetone, and p‐dioxane. The infrared spectrum of the polymer indicated peaks at 1735 cm.−1 characteristic of the carbonyl group, and at 1200–1000 cm.−1 characteristic of the acetal group, while no absorption at 990 and 3100 cm.−1 due to the vinyl group was observed. The spectra of the polymers obtained by AIBN and by γ‐ray irradiation were essentially identical. The saponified product of the polymer was white powder and its reduced viscosity was a little larger than that of the original polymer. These results indicate that the polymer has no ester unit in the main chain. The results of gas chromatographic analysis of the saponified product of the polymer, indicate the presence of a small amount of ethyl alcohol. The results of the saponification showed that the ester content in the polymer varied from 7 to 25% depending upon the polymerization temperature. These results indicate that 2‐vinyl‐1,3‐dioxolane polymerized by AIBN or by γ‐irradiation with two modes of vinyl and hydrogen migration, yielding a copolymer having the unit structures magnified image
Stereoregular condensation polymers. I. Synthesis and comparison of optically active and inactive polycamphorates and polycamphoramides
Authors: Toy Madeline S.
Published: April 2003

Optically active and inactive polycamphorates and polycamphoramides were prepared by polycondensation of d‐ and dl‐camphoryl dichloride with 1,4‐butanediol, bisphenol A, and piperazine. The higher melting and more crystalline properties of optically active stereoregular condensation polymers compared to inactive atactic forms appear consistent with results from optically active isotactic and inactive atactic addition polymers.
Mechanism of Ziegler‐Natta polymerization of propylene and α‐d‐propylene
Authors: Overberger C. G. , Jarovitzky P. A. , Mukamal H.
Published: April 2003

Rates of propylene homopolymerization and α‐d‐propylene‐propylene copolymerization were determined by using constant‐pressure polymerization conditions. It could be demonstrated that the rate of propylene homopolymerization was constant under the conditions used. However, the initial rate of copolymerization was faster and decreased with time to the rate obtained for propylene homopolymerizations. The higher initial copolymerization rate was attributed to the stabilization of potentially active centers in solution when the deuterated monomer was present. These active centers are assumed to be formed by reactions of tetravalent titanium with monomer. These active centers, which are formed in solution, are said to be destroyed by isotopically controlled reactions, i. e., abstraction of the hydrogen or the α‐deuterium atom from these monomer‐alkylated species in solution or at the interface. These active centers are believed to be adsorbed and/or chemisorbed onto the precipitated catalyst surface and to be responsible for a polymer of considerably lower steric order. This scheme predicts a stereoregular polymer of high molecular weight produced by polymerization on a Ti(III) surface and a largely amorphous polymer of lower molecular weight produced by adsorbed and/or chemisorbed species. This prediction was verified by fractionation of the deuterated polymers into crystalline and amorphous portions.
Cyclopolycondensations. VII. Preparation of aromatic poly(ureido acids) by the low‐temperature solution polymerization and cyclodehydration to fully aromatic polyquinazolinediones
Authors: Tohyama Shunroku , Kurihara Masaru , Ikeda Kojuro , Yoda Naoya
Published: April 2003

Fully aromatic polyquinazolinediones (IV) of high molecular weight were obtained by thermal cyclodehydration of aromatic poly(uredio acids) (III) prepared by the polyaddition reaction of 4,4′‐diaminobiphenyl‐3,3′‐dicarboxylic acid (I) with aromatic diisocyanates (II). From the kinetic study of reactions of model systems (anthranilic acid with phenyl isocyanate) in the presence of a variety of basic catalysts, it was established that tertiary amines had the highest catalytic activity for the formation of ureido linkage. The optimum polymerization conditions were determined by the study of reaction variables such as monomer concentration, polymerization temperature, monomer ratio, and catalyst concentration. The effect of polarity and purity of organic solvents and reactants was also studied.
Alkyl vinyl esters of brassylic (tridecanedioic) acid
Authors: Chang Shu‐Pei , Miwa Thomas K. , Wolff Ivan A.
Published: April 2003

Brassylic acid was partially esterified at 77°C. in toluene solution with ethyl, 2‐methylpentyl, or nonyl alcohol and with p‐toluenesulfonic acid used as catalyst. Half‐esters were isolated from the respective reaction mixtures in yields of 28, 34, and 32% after reaction times of 2,6, and 8 hr. Both recovered brassylic acid and byproduct dialkyl ester were successfully used as starting materials in subsequent esterifications. Consequently, conversion of starting materials to half‐ester would be increased in a process that involved continuous recycling of byproducts. Alkyl hydrogen brassylates were vinylated at 165°C. for 8 hr. with acetylene at 360 psig. The zinc salt generated in situ from zinc oxide served as catalyst and toluene as solvent. Yields were 80–88% and purities of products were 94–95%. Samples of 2‐methylpentyl vinyl brassylate and nonyl vinyl brassylate of much higher purity were obtained by preparative gas–liquid chromatography or molecular distillation. Physical properties and experimental conditions for gas–liquid chromatographic analyses of both the alkyl hydrogen and alkyl vinyl brassylates are reported.
Synthesis and polymerization of 1,3‐bis‐(2,3‐epoxypropylphenyl)tetramethyldisiloxanes and related compounds
Authors: Bilow N. , Lawrence R. E. , Patterson W. J.
Published: April 2003

1,3‐Bis[p‐(2,3‐epoxypropyl)phenyl]tetramethyldisiloxane and its meta isomer were synthesized and subsequently cured with m‐phenylenediamine. Dielectric properties of the cured resin derived from the para isomer were measured between 25 and 100°C. The ambient temperature dielectric constant of the resin at 1 kc./sec. was 3.4, its dissipation factor was 0.01, and its volume resistivity was 1014 ohm‐cm. at 500 v. d.c. Several allylphenylsiloxanes were also prepared by the cohydrolysis of allylphenyldimethylethoxysilane with dimethyldiethoxysilane, bis(dimethylethoxysilyl)benzene, and methyltriethoxysilane. Preliminary epoxidation studies on these latter materials were also carried out.
Radiation‐induced polymerization of 1,1,2‐trichlorobutadiene
Authors: Matsuda Tatsuo , Fujii Shigetada
Published: April 2003

The γ‐ray‐induced polymerization of 1,1,2‐trichlorobutadiene, m.p. −48.5°C., was investigated in the temperature range from +55 to −196°C. In the liquid state, the following results were obtained: (1) the rate decreases with decrease of temperature (Ea = 8.0 kcal./mole); (2) the dose rate dependences of rate and of molecular weight are 0.49 and −0.25, respectively; (3) the reaction is inhibited by DPPH; (4) the structure of the polymer is predominantly 1,4 units. It was concluded that the liquid‐state polymerization proceeds by a radical mechanism, and the radical yield was found to be 19.7. In the solid state, the following results were obtained: (1) the rate is considerably higher than in the liquid state immediately above the melting point and gradually decreases with decrease of temperature (Ea = 0.34 kcal./mole); (2) the dependence of the rate on dose rate is unity while the molecular weight is independent of the dose rate; (3) the reaction rate is unaffected by DPPH and accelerated by dimethylformamide; (4) the structure of the polymer, 3,4 units, is completely different from that of the polymer obtained in the liquid‐state polymerization. The solid‐state polymerization is probably of a different nature and is not well elucidated.
Polynomial expansion of log relative viscosity and its application to polymer solutions
Authors: Palit Santi R. , Kar Indrajit
Published: April 2003

Solomon and Ciuta's equation has been deduced from first principles and has been shown to be merely an algebraic consequence of the definition of intrinsic viscosity. Secondly, a consequence of this equation that [η]c should be linear with \documentclass{article}\pagestyle{empty}\begin{document}$\sqrt {2\eta {\rm sp} - 2\ln \eta {\rm rel}}$\end{document}
with unit slope, is found to be fairly accurate when examined against literature and our own data, and so this equation is commended not only for single‐point determination of [η] but also for representing viscosity variation with concentration up to ηsp < 0.60. Thirdly, higher‐order approximations are found to be less suitable. Other consequences of Solomon and Ciuta's equation are discussed.
Arylene‐modified siloxanes
Authors: Breed L. W. , Elliott R. L. , Whitehead M. E.
Published: April 2003

Polyarylenepolysiloxanes with varied structure can be obtained in condensation reactions of arylenedisilanols and N‐methylsiloxazanes. Molecular weights, viscometric properties, glass transition temperatures, and thermogravimetric analysis data are reported.
Endgroup study of chlorate–sulfite‐initiated acrylonitrile copolymer
Authors: Shibukawa T. , Sone M. , Uchida A. , Iwahori K.
Published: April 2003

Quantitative determination of endgroups in an acrylonitrile–methyl acrylate (90:10) copolymer polymerized with NaClO3–Na2SO3 redox system in aqueous solution was carried out by conductometric and dyeing methods for SO3H incorporated into polymer, x‐ray analysis for S in polymer, and polarography for Cl in polymer. The number‐average molecular weight was measured by osmometry. Determination of endgroups was done on both unfractionated polymer and fractionated polymer. On the average, 0.95 mole S and 0.71 mole SO3H per molecule were found in unfractionated polymer. For fractionated polymer, 0.68 mole S and 0.69 mole SO3H per molecule were found. A small amount of Cl was also found in both unfractionated polymer and fractionated polymer. The difference between results for the two polymers and polymerization kinetics are discussed.
Polymerization of DL‐alanine NCA and L‐alanine NCA
Authors: Iwakura Yoshio , Uno Keikichi , Oya Masanao
Published: April 2003

The polymerization of N‐carboxy‐DL‐alanine anhydride and N‐carboxy‐L‐alanine anhydride were carried out in various solvents such as acetonitrile, dimethyl sulfoxide (DMSO), and nitrobenzene. The x‐ray diffraction diagram and the infrared spectra of the polymers of DL‐ and L‐alanine were obtained. The polypeptides obtained in acetonitrile and in nitrobenzene were in the α conformation, and the conformation of polypeptide obtained in acetonitrile was not influenced by its molecular weight. The polypeptide obtained in DMSO was essentially in the β conformation. It was observed that the α and β forms of polyalanine were altered on treatment of the polymer with m‐cresol, dichloroacetic acid, or formic acid.
Polymerization of acrylamide initiated by the persulfate–thiosulfate redox couple
Authors: Riggs J. P. , Rodriguez F.
Published: April 2003

Conversion–time data were obtained for the polymerization of acrylamide initiated by the redox couple persulfate–thiosulfate by using a dilatometer. A plot of initial rate as a function of thiosulfate concentration shows a well‐defined maximum and three distinct regions of behavior. In each region the shape of the conversion–time curves demonstrates the differences in apparent order with respect to monomer arising from changes in initiator concentration during an individual run. A reaction mechanism is proposed to explain the results, and a limiting form of the rate expression is derived for each of the three regions. The ranges of concentration studied are: persulfate, 9.5 × 10−4−4.7 × 10−2M; thiosulfate, 2 × 10−5−2 × 10−2M; initial monomer, 0.05–1.0M; and temperature, 30–50°C. Within these ranges the initial rate shows a halforder dependence on persulfate and a first‐order dependence on initial monomer concentration.
Association of polyacrylonitrile prepared by low‐temperature, solution polymerization with an organometallic catalyst
Authors: Chiang R. , Stauffer J. C.
Published: April 2003

The weight‐average molecular weights of polymers of acrylonitrile prepared by a free‐radical initiator and an organometallic catalyst have been determined by lightscattering measurements in N,N‐dimethylformamide, dimethyl sulfoxide, and dimethylacetamide at 25°C. and in dimethyl sulfoxide at 140°C. The apparent molecular weights of the polymers prepared with the NaAlEt3S(i‐Pr) catalyst in DMF at −78°C. (referred to as high‐melting polymers) changed from 54,800, 82,700, and 480,000 when measured in DMF at 25°C. to 36,000, 41,600, and 225,000 when measured in DMSO at 140°C., whereas the molecular weights of the free‐radical polymers remained unchanged. Furthermore, from results obtained in DMSO at 140°C., The intrinsic viscosity–molecular‐weight relationships were found to be identical for the high‐melting and the free‐radical polymer and in substantial agreement with an equation reported by Cleland and Stockmayer. The apparent decrease in molecular weight of the high‐melting polymer from 25 to 140°C. indicates rather clearly that the high‐melting polymers are associated in DMF at 25°C. The “aggregates,” even though present only at low concentrations, raised the weight‐average molecular weight markedly but affected the number‐average molecular weight only slightly, thus giving a high M̄w/M̄n ratio. It appears likely that when temperature and solvent are such that association does not occur, linear PAN's will have approximately the same intrinsic viscosity–molecular weight relationship (subject of course to slight change by polydispersity). The often reported abnormal molecular weight of samples prepared by solution polymerization especially at low temperatures, may be attributed to branching, or to an association, as reported here. The nature of association of PAN in dilute solution is also discussed.
Degradation of poly(ethylene oxide) by high‐speed stirring
Authors: Minoura Yuji , Kasuya Tanekazu , Kawamura Shinji , Nakano Akihiko
Published: April 2003

Degradation of poly(ethylene oxide) (PEO) by violent stirring was studied in various solvents. The chain scission or the limit of the degradation was measured, and the effects of solvents, polymer concentration, stirring speed and degree of polymerization (DP) were investigated. It was found that the number of bonds broken per polymer chain was independent of the concentration but increased with the stirring speed and with decrease in the DP. The rate was much affected by the solvent used, being larger in a poor solvent. It was also found that the rate could be represented either by Jellinek's or Ovenall's rate equations, which have been applied to the ultrasonic degradation of polymers in solution.
General description of optical dichroic orientation factors for relating optical anisotropy of bulk polymer to orientation of structural units
Authors: Nomura Shunji , Kawai Hiromichi , Kimura Itzuro , Kagiyama Mitzuyasu
Published: April 2003

The relationship between the optical anisotropy of high polymeric materials in bulk and the orientation of structural units within the materials was described in general by using several types of mean values of the orientation distribution function of three Eulerian angles, i.e., the orientation factors, under some assumptions about the symmetry of the function being applicable for the most of the industrial products. A newly defined biaxial orientation factor, Fθηi = 〈sin2 θj cos 2ηj〉, where θj and ηj are the polar and azimuthal angles of the jth axis within the structural unit with respect to the bulk axes, may relate the biaxial orientation of the structural units to the dichroic orientation factors, which are measurable optical anisotropic indices of the bulk materials. Some applications of the results to the birefringence and infrared and dye dichroism are also discussed.
On the use of a random parameter in the theory of depolymerization of long‐chain molecules
Authors: Coyne Brian J.
Published: April 2003

Equations for the time course of depolymerization of long‐chain polymers are derived by the method of randomization of a parameter for the case in which all bonds have equal probability of cleavage. This yields some gain in insight and avoids the necessity for solving systems of differential equations.
Sorption of organic vapors into drawn and undrawn polyethylene
Authors: Peterlin A. , Williams J. L. , Stannett V.
Published: April 2003

Drawing of linear polyethylene at 60°C. to an extension ratio of ten drastically reduces the sorption and diffusion of n‐pentane, benzene, methylene chloride, and tetrachloroethylene. Methylene chloride was chosen for more detailed study. The sorption is of the normal Fickean type. It is also fully reversible in the temperature range between 25 and 45°C. if the sorbed amount is kept to below 0.5%. At higher concentrations the sample relaxes so that sorption irreversibly increases. The reversible sorption per gram of amorphous component is about 1/6 of that in undrawn polyethylene. The diffusion constant has a larger temperature and concentration dependence than in the undrawn material. At zero concentration the activation energy for diffusion is 34.4 kcal./mole and the diffusion constant at 25°C. is 8 × 10−11 cm.2/sec. as compared with 14.4 kcal./mole and 1.5 × 10−8 cm.2/sec. in undrawn PE. Cold drawing reduces the sorption sites without changing their energy content, but drastically cuts down diffusion and increases the activation energy. A smaller part of the increase of the latter is a consequence of the lower enthalpy of the amorphous material and a larger part is probably due to the increased distance between sorption sites.
Viscoelasticity of textile fibers at finite strains
Authors: Hall I. H.
Published: April 2003

Experimental data obtained from stress–strain curves of five different textile fibers, at a series of different, constant strain rates covering a range of 61/2 decades have been used to study two methods of nonlinear viscoelastic analysis proposed elsewhere. According to the first of these, time and strain effects are factorizable so that stress σ, strain ε and time t are related by the equation σf1(ε)/ε = f(t),. This is shown to be unsatisfactory with the present materials, but an empirical modification to σf1(ε)/ε = f2(ε) + f(t) is satisfactory. According to the second, general nonlinear viscoelastic behavior can be described by an equation which reduces to the form σ/ε = F1(t) + εF2(t) + ε2F3(t) + when applied to extension at a constant strain rate. This series is shown to be strongly divergent except at fairly small stains. In fact, if it is truncated after about three terms, which are as many as can be estimated with any significance in the present experiments, it is applicable only to strains of about 3–4% and less. Numerical techniques which enable standard statistical procedures to be used have been devised to perform the above analyses and are described in detail.
Cationic polymerization of formaldehyde in liquid carbon dioxide. Part II: A kinetic study of the polymerization
Authors: Yokota Hisao , Kondo Masatsune , Kagiya Tsutomu , Fukui Kenichi
Published: April 2003

The kinetic behavior on the polymerization of formaldehyde with and without acidic catalyst, in liquid carbon dioxide, in the temperature range of 30 to 50°C. was investigated. In the polymerization without catalyst both the polymer yield and the degree of polymerization increased with reaction time and also with rising temperature. With acidic catalyst, such as acetic acid and dichloroacetic acid, both the polymer yield and the degree of polymerization increased more than that in the polymerization without catalyst. The overall rate of polymerization with and without acidic catalyst was expressed by the first‐order rate equation with respect to monomer concentration. From the results it was concluded that the polymerizations belonged to a type of successive polymerization with rapid initiation and no termination. The rate constant and the activation energy of each elementary process of polymerization were estimated on the basis of the results.
The synthesis of some optically active C‐methylated 2‐oxohexamethyleneimines
Authors: Overberger C. G. , Parker Gordon M.
Published: April 2003

Three new, optically active, methyl‐substituted 2‐oxohexamethyleneimines were prepared by cyclization of the respective optically active C‐methylated 6‐aminohexanoic acids. The active forms of the amino acids used for the preparation of (−)‐3‐methyl‐2‐oxohexamethyleneimine and (−)‐7‐methyl‐2‐oxohexamethyleneimine were obtained by resolution of their diastereomeric quinine salts. s‐(+)‐5‐methyl‐2‐oxohexamethyleneimine was synthesized without racemization from optically pure 2‐isopropylidene‐5‐methyleyclohexanone (pulegone).
Chain transfer for vinyl monomers polymerized in N‐allylstearamide
Authors: Jordan Edmund F. , Artymyshyn Bohdan , Wrigley A. N.
Published: April 2003

Apparent transfer constants have been determined for styrene, methyl methacrylate vinyl acetate, and diethyl maleate polymerized in N‐allylstearamide at 90°C. Regression coefficients for transfer were: methyl methacrylate, 0.301 × 10−3; styrene, with no added initiator, 0.582 × 10−3; styrene, initiated with benzoyl peroxide, 0.830 × 10−3; vinyl acetate, 62.01 × 10−3; and diethyl maleate, 2.24 × 10−3. Rates of polymerization were retarded for both styrene and methyl methacrylate. Vinyl monomer and comonomer disappearance followed an increasing exponential dependence on both initiator and monomer concentration. Although degradative chain transfer probably caused most of the retardation, the cross‐termination effect was not eliminated as a contribution factor. Rates for the vinyl acetate copolymerization were somewhat retarded, even though initiator consumption was large because of induced decomposition. The kinetic and transfer data indicated that the reactive monomers added radicals readily, but that rates were lowered by degradative chain transfer. Growing chains were terminated at only moderate rates of transfer. Unreactive monomers added radicals less easily, producing reactive radicals, which transferred rapidly, so that molecular weights were lowered precipitously. Although induced initiator decomposition occurred, rates were still retarded by degradative chain transfer. A simple empirical relation was found between the reciprocal number‐average degree of polymerization, 1/X̄n1 and the mole fraction of allylic comonomer entering the copolymer F2, which permitted estimation of the molecular weight of copolymers of vinyl monomers with allylic comonomers. This equation should be applicable when monomer transfer constants for each homopolymer are known and when osmometric molecular weights of one or two copolymers of low allylic content have been determined.
Emulsion polymerization. III. Theoretical prediction of the effects of slow termination rate within latex particles
Authors: Gardon J. L.
Published: April 2003

The Smith‐Ewart theory predicts that there is an interval during an isothermal homopolymerization when the conversion varies linearly with time. This prediction rests on the assumptions that, during this interval II, the particle number is constant, the monomer concentration in the particles is constant, and the termination rate within the particles is instantaneous, so that the average number of radicals per particle Q is half. In this paper this latter assumption is abandoned. If the termination rate is slow, two or more radicals can coexist in a particle. The termination rate within a particle becomes a function of the particle size because of the decreased probability that two radicals meet for termination in a given time when the volume in which these radicals are located increases. It follows that with increasing conversion the termination rate decreases. Stockmayer's calculations based on this model neglected the variation of particle volume with time, and it was assumed that a steady state of radical concentration in particles exists. In the present calculations these restrictive assumptions were not used. Stockmayer calculated only how Q should vary with conversion. In the present paper several experimentally verifiable consequences of the model are shown. The new calculations show that the interval II conversion‐time curve can be represented by the formula At2 + Bt, where B is the Smith‐Ewart rate and is proportional to the particle number and the parameter A is independent of the particle number and depends mainly on initiation and termination rates. From A and B and propagation and termination rate constants can be calculated. With the aid of parameters A and B the conversion dependence of molecular weight and of Q can also be predicted for interval II. In the theoretical calculations the distribution of radicals among particles is established. It is shown that for a given value of Q this distribution is unique, independent of the experimental conditions leading to this Q. This distribution was derived solely from kinetic considerations and is analogous to the statistical Poisson distribution. With increasing Q, i.e., with increasing conversion, this distribution broadens. Since each particle grows proportionally to the number of radicals in it, particles must grow at greatly varying rates if there is broad distribution of radicals among them. It follows that the particle size distribution has to broaden with increasing conversion, contrary to predictions based upon the Smith‐Ewart model. At present it is not yet possible to predict quantitatively the shape of the conversion‐time curve in interval III, the interval following the disappearance of monomer droplets. The reason for this is that the functional dependence of the termination rate constant upon monomer concentration in the particles is not known. However, once the conversion‐time curve is experimentally determined, it is possible to calculate from it the interval III values of Q and of molecular weight.
Two‐stage irradiation study on propagation and termination in the γ‐radiation‐induced polymerization of ethylene in liquid carbon dioxide
Authors: Hagiwara Miyuki , Mitsui Hiroshi , Machi Sueo , Kagiya Tsutomu
Published: April 2003

The propagation and termination reaction in the γ‐radiation‐induced ethylene polymerization in liquid carbon dioxide were investigated by a two‐stage irradiation. After irradiation at high dose rate, the polymerization occured at a considerable rate under the extremely low dose rate without initiation. The absolute propagation rate was determined in the second stage to be proportional to the square of ethylene fugacity and depended slightly on dose rate. The apparent activation energy for the propagation reaction is −9 kcal./mole. From these observations which are the same as those in bulk polymerization, it is concluded that carbon dioxide acts as a diluent of ethylene monomer in the propagation reaction. Also, carbon dioxide was shown to be inactive to the growing radicals without irradiation, but oxygen which is produced by the radiolysis of carbon dioxide at high dose terminates the growing radicals with formation of carbonyl in the polymer.
Polyaryläther‐Kondensationsprodukte des 4,4′‐bis(chloromethylphenyl) äthers mit manchen diphenolen
Authors: Tokarzewska Maria
Published: April 2003

Poly(aryl ethers) as products of the polycondensation of 4,4′‐bis(chloromethylphenyl) ether with sodium salts of various phenols have been prepared in the Williamson reaction. The reaction was carried out at three different temperatures (78, 140, and 185°C.) in ethanol, xylene, and tetralin, respectively. The effect of the polycondensation and the nature and composition of initial components on the properties of the products has been studied. The molecular weights and the melting temperature of the synthesized resins increased with increasing reaction temperature. The structure and molecular weight have a pronounced effect on the properties of the resins. Resins prepared from 4,4′‐dihydroxydinaphthyl had the highest melting temperature and were practically insoluble, while the resins prepared from 2,2′‐dihydroxydinaphthlmethane had the lowest melting temperature and were soluble in practically all organic solvents. On the basis of the experimental data a reaction scheme appropriate for the synthesis of poly(aryl ethers) from the phenolates as well as from the free phenols in the presence of NaOH has been proposed. Some thermal and mechanical properties of poly(aryl ethers) have been determined. Thermal treatment of the resins above theri softening temperature resulted in an elevated softening point too. This is explained by the supplementary condensation of both chlorine or hydroxyl endgroups in the molten resins.
Study of Ziegler‐Natta catalysts. Part III. Effect of the structure of titanium trichloride on the polymerization of propylene
Authors: Kollár L. , Simon A. , Kalló A.
Published: April 2003

In addition to differences among the various modifications of TiCl3there may be certain structural differences even among α‐TiCl3samples prepared by differences methods. Electron microscopic examination of two samples has revealed widely different free surfaces, in spite of the fact that both the specific surfaces (measured by adsorption) and the polymerization activities were identical. This might be explained by the finding that the surfaces of the free lateral planes and the quantities of the free edges are the same. This explanation is in agreement with the assumption of Rodriguez and his co‐workers that the active centers of polymerization are situated on the lateral planes and edges of the TiCl3crystals.
Physicochemical and macromolecular properties of sodium amylose xanthate in dilute solution
Authors: Pramanik A. G. , Choudhury P. K.
Published: April 2003

Sodium amylose xanthate has been studied in dilute solution. Potato starch was fractionated for this purpose into amylose and amylopectin fractions. Amylose was xanthated in solution under alkaline conditions and the Na amylose xanthate was then characterized by reaction with I2 solution and ultraviolet spectra of the xanthate groups determined. Stability of the xanthate in alkaline condition under both oxygen and nitrogen atmospheres was also investigated. From light scattering measurements of dilute salt solutions of Na amylose xanthate, the weight‐average molecular weight Mw as well as the molecular dimensions were determined. In 0.11M NaCl, which conforms to the θ solvent, Na amylose xanthate molecules appear to have a random‐coil configuration. Two other configurational parameters, such as the effective bond length b, and the steric factor σ, i.e., (R02)1/2/(Rf2)1/2, where (R02)1/2 is the Root‐mean‐square end‐to‐end distance in the unperturbed state and (Rf2)1/2 is the unperturbed value calculated on the assumption of free rotation about each intermonomer CO bond of the amylose chain were also calculated and found to be 6.24 and 1.020, respectively. It is thus concluded that the amylose chain in Na amylose xanthate behaves as a typical flexible coil in dilute salt solution.
The thermal degradation of acrylic acid–ethylene polymers
Authors: McGaugh M. C. , Kottle Sherman
Published: April 2003

A Study of the thermal degradation of a copolymer of ethylene and acrylic acid is presented. The degradation mechanism of the acrylic acid portion of the polymer was found to be dehydration of the acid, forming anhydride, and decarboxylation of the anhydride, forming unsaturation. The resultant unsaturation reduces the copolymer‐s stability to both thermal and oxidative degradation.
Polymers with quinoxaline units. III. Polymers with quinoxaline and thiazine recurring units
Authors: Okada Masahiko , Marvel C. S.
Published: April 2003

Six ladder or partly ladder polymers have been prepared by the condensation reactions of combinations of two diaminodithiophenols, 4,6‐diamino‐1,3‐dithiophenol and 3,3′‐dimercaptobenzidine, with three tetrachloroquinoxaline derivatives, 2,3,7,8‐tetrachloro‐1,4,6,9‐tetraazaanthracene, 2,2′,3,3′‐tetrachloro‐6,6′‐bisquinoxaline, and 2,2′,3,3′‐tetrachloro‐6,6′‐diquinoxalyl ether, with the use of dimethylacetamide, hexamethylphos phoramide, and polyphosphoric acid as reaction media. The polymers thus obtained are highly colored, powedery materials which are slightly soluble in methanesulfonic acid and concentrated sulfuric acid. These polymers (ηinh > 1) show good thermal stability.
Inorganic coordination polymers. X. Observations on the formation and nature of poly(di‐μ‐diphenylphosphinato‐hydroxyaquochromium (III)),{Cr(H2O)(OH)‐[OP(C6H5)2O]2}x
Authors: Maguire K. D. , Block B. P.
Published: April 2003

Under different conditions two products, one green and one brown, were obtained by the air oxidation of chromium(II) diphenylphosphinate. Air oxidation of an aqueous suspension of the phosphinate apparently yields a mixture in which the green form predominates. As initially isolated, the green form is a low molecular weight polymer corresponding to {Cr(H2O)(OH)[OP(C6H5)2O]2}n, with n approximately 11. It spontaneously polymerizes further in organic solvents to high molecular weight polymers of the same composition, with n in the range 150–200. This polymerization reaction in volves the elimination of water and is probably a reaction between endgroups resulting in a basically linear polymer. The brown product, corresponding to low molecular weight {Cr2(H2O)(OH)2[OP(C6H5)2O]4}p, also polymerizes spontaneously but at a faster rate and to a gel. The polymer so produced is less soluble than that produced from the low molecular weight green product and is probably crosslinked.
Polymerization initiated by the charge‐transfer complex of styrene and maleic anhydride in the presence of cumene and of cumene and liquid sulfur dioxide
Authors: Matsuda Minoru , Abe Katsuhiro
Published: April 2003

A polymerization was induced with a charge‐transfer type of complex consisting of styrene and maleic anhydride in the presence a solvent such as ethyl benzene, cumene, or p‐cymene. No polymer was obtained either when the solvent was missing from the polymerization system or when benzene, toluene, or xylene, which are relatively stable to hydrogen abstraction, was added to the polymerization system. An effective initiation, however, took place when cumene or p‐cymene, each of which has a labile hydrogen on an α carbon, was added. On the basis of elementary analysis and infrared spectroscopy the formation of copolymer containing substantially equimolar amounts of styrene and maleic anhydride was ascertained. This polymerization was inhibited by the addition of DPPH, suggesting that the system styrene–maleic anhydride–cumene functions much as a conventional free‐radical initiator. On the other hand, when a solution of cumene and liquid sulfur dioxide was added to the polymerization system, polystyrene was obtained. This polymerization was inhibited by the addition of a base such as dimethyl‐formamide or dimethyl sulfoxide, indicating that the polymerization proceeds through carbonium ion intermediates. The addition of ethyl benzene or of p‐cymene brought about the same result as cumene. It is conceivable that the polymerization is induced by the abstraction of hydrogen attached at the α position of cumene by means of the charge‐transfer complex of styrene and maleic anhydride.
Polymers with quinoxaline units. IV. Polymers with quinoxaline and oxazine units
Authors: Wolf Rainer , Okada Masahiko , Marvel C. S.
Published: April 2003

Six ladder or partly ladder polymers have been prepared by the condensation of diaminodiphenols with tetrachloro‐ or terahydroxyquinoxaline derivatives with the use of poly (phosphoric acid), pyridine, and naphthalene as reaction media. The polymers thus obtained are highly colored powdery materials which are slightly soluble in concentrated sulfuric acid and methanesulfonic acid. These polymers show good thermal stability.
On the heat of solution of polymer with solvent: Polydimethylsiloxane–solvent systems
Authors: Morimoto Satoshi
Published: April 2003

Heats of mixing and excess volumes at infinite dilution have been obtained at 25°C. for polydimethylsiloxane or its lower oligomers in various solvents by using a twin conduction microcalorimeter and from the pycnometric specific volumes. From those values, excess energies ΔEMv at constant volume have been determined. The prediction on intramolecular conformation contributions to the heat of solution as proposed by Bianchi has been evaluated by the values of ΔEMv. The heat of solution in the polymer–solvent systems was interpreted by the expression for ΔEMv derived from the Van Laar‐Hildebrand work on simple liquid mixtures with the solubility parameters of polymers obtained from indirect measurements. The values of conformational intramolecular energy change calculated from dilute solution properties were difficult to rationalize with our results. Our present results suggest that systems in a nonideal state can not be distinguished for certain from those in the ideal state. This conclusion based on apparent values does not deny the possible effect of the conformational energy change.
Polycarboxyhydrazides with ferrocenylene groups in the main chain
Authors: Neuse Eberhard W. , Rosenberg Harold
Published: April 2003

Polycarboxyhydrazides essentially of the type \documentclass{article}\pagestyle{empty}\begin{document}$ \rlap{--} [{\rm C}_{10} {\rm H}_8 {\rm Fe}\hbox{---}{\rm CONHNHCO}\rlap{--}]_n $\end{document} are synthesized by low‐temperature solution condensation of 1,1′‐di(chlorocarbonyl) ferrocene with hydrazine or 1, 1′‐ferrocenedicarboxyhydrazide and hexamethylphosphoramide as solvent. In an analogous manner the polycondensation of 1, 1′‐di(chlorocarbonyl)ferrocene with oxalyldihydrazide leads to polyhydrazides essentially possessing the structure \documentclass{article}\pagestyle{empty}\begin{document}$ \rlap{--} [{\rm C}_{10} {\rm H}_8 {\rm Fe}\hbox{---}{\rm CONHNHCO}\hbox{---}{\rm CONHNHCO}\rlap{--}]_n $\end{document}. Both polymer types exhibit inherent viscosities (0.08–0.19 dl./g.) considerably lower than reported for analogous aliphatic or benzene‐aromatic polyhydrazides. This behavior points to premature chain termination via heterobridging imide groups as a result of the welldocumented tendency of appropriately substituted ferrocene compounds to undergo intramolecular cyclization. In addition, elemental analytical and spectroscopic evidence, coupled with the failure of both polymer types to undergo cyclodehydration to the corresponding 1,3,4‐oxadiazole polymers upon heat treatment, suggests some structural irregularities in the aliphatic connecting segments arising from ferrocenoylation of secondary amino groups with resultant branching. With the polyhydrazide prepared from 1, 1′‐di(chlorocarbonyl)ferrocene and 1, 1′‐ferrocenedicarboxyhydrazide it is shown spectroscopically that treatment with alkali results in conversation of the nonconjugated hydrazide structure of the connecting segments into the polyconjugated tautomeric enol form comprising azine groups.
Copolymerization of vinylsilanes with styrene
Authors: Iwakura Yoshio , Toda Fujio , Hattori Kenjiro
Published: April 2003

New vinylsilanes (M2), i. e. phenylvinylsilane (I), allylmethylsilane (II), allylphenylsilane (III), and p‐vinylphenylmethylsilane (IV), were prepared and copolymerized with styrene (M1). The monomer reactivity ratios were r1 = 5.7 and r2 = 0, r1 = 36 and r2 = 0, r1 = 29 and r2 = 01, and r1 = 0.91 and r2 = 1.1, respectively. From the results of infrared and NMR spectra it was indicated that the vinylsilanes participated in copolymerization in the form of a vinyl type of polymerization and not in the form of a hydrogen‐transfer type of polymerization. The reaction of copolymer with alcohols and methyl methacrylate and appropriate catalysts was investigated.
Ferrocene‐containing polyesters and polyamides
Authors: Pittman Charles U.
Published: April 2003

A series of ferrocene‐containing polyesters and polyamides were prepared by refluxing 1,1′‐dichlorocarbonylferrocene with various diols and primary diamines in xylene–pyridine solvent. The polyamides were all solids, but some of the polyesters were liquids. Reported are the infrared spectra and solubility characteristics of all the polymers and, where possible, the molecular weight and molecular weight distributions. In general, these polyamides and polyesters were of relatively low molecular weight (below 4000), but the polyesters were readily chain extended and crosslinked by di‐ and triisocyanates. Elemental analyses are reported for all the polymers prepared.
Polymers derived from fluoroketones. II. Wetting properties of fluoroalkyl acrylates and methacrylates
Authors: Pittman Allen G. , Sharp Dennis L. , Ludwig Barbara A.
Published: April 2003

The critical surface tension of wetting (γc) for certain branched‐chain polymeric fluoroalkyl acrylates and methacrylates was obtained. Polymeric materials utilized in this study can be represented by the repeating units

, where R is H or CH3, R′ is H or F, and X is F or Cl, by \documentclass{article}\pagestyle{empty}\begin{document}$ \rlap{--} [{\rm CH}_2\hbox{---}{\rm CH}({\rm COO}({\rm CH}_2)_n {\rm OCF -}({\rm CF}_3)_2)\rlap{--}] $\end{document}, where n is 2, 5, or 11, and by \documentclass{article}\pagestyle{empty}\begin{document}$ \rlap{--} [{\rm CH}_2 \hbox{---}{\rm C}({\rm R})({\rm COOCH}_2 ({\rm CF}_2)n'{\rm CF}_3)\rlap{--}] $\end{document}, where R is H or CH3 and n′ is 2 or 6. Monomer synthesis involved either the direct acylation of a fluoroketone–metal fluoride adduct or a fluoroalcohol with acryloyl or methacryloyl chloride or a displacement reaction between a fluoroketone–metal fluoride adduct and an ω‐bromoester. In general, modifications in the pendent fluoroalkyl group affected γc in a manner predictable from previous work by Zisman et al.; e.g., γc was increased when either H or Cl was substituted for F in the side chain. In polymeric alkyl acrylates containing a heptafluoroisopropyl side chain γc increased as the fluorocarbon group was removed from the proximity of the polymer backbone by intervening methylene groups. A comparison of the wetting properties of polyacrylates containing either a perfluoroisopropyl or n‐perfluoropropyl group showed that the polymer containing the isopropyl group had a lower γc.
Polymers derived from fluoroketones. III. Monomer synthesis, polymerization, and wetting properties of poly(allyl ether) and poly(vinyl ether)
Authors: Pittman Allen G. , Ludwig Barbara A. , Sharp Dennis L.
Published: April 2003

The synthesis and polymerization of a series of perhaloalkyl allyl and vinyl ethers derived from perhaloketones is described. Data on the critical surface tension of wetting (γc) for high molecular weight polymers of heptafluoroisopropyl vinyl ether and low molecular weight poly(heptafluoroisopropyl allyl ether) is also presented. Preparation of the allyl ethers is a one‐step, high‐yield displacement reaction between the potassium fluoride–perhaloacetone adduct and an allyl halide, such as allyl bromide. The vinyl ethersare prepared by a two‐step process which involves displacement of halide from a 1,2‐dihaloethane with a KF–perhaloacetone adduct and dehydrohalogenation of the 1‐halo‐2‐perhaloalkoxyethane to a vinyl ether. Low molecular weight polymers were obtained with heptafluoroisopropyl allyl ether by using a high concentration of a free‐radical initiator. The low molecular weight poly(heptafluoroisopropyl allyl ether) had a γc of 21 dyne/cm. No polymer was obtained with tributylborane–oxygen or with VCl3–AIR3, with gamma radiation, or by exposure to ultraviolet light. High molecular weight polymers were obtained from heptafluoroisopropyl vinyl either by using either lauryl peroxide or ultraviolet light but not by exposure to BF3–etherate. The γc for poly(heptafluoroisopropyl vinyl ether) ranged from 14.2 to 14.6 dyne/cm., and the significance of this value is discussed in relation to the γc for poly(heptafluoroisopropyl acrylate).
Effect of surfactants on the polymerization of acrylamide in aqueous solutions
Authors: Friend J. P. , Alexander A. E.
Published: April 2003

The polymerization of acrylamide in aqueous surfactant solutions, initiated by potassium persulfate, has been investigated, dilatometry being used to follow the conversion. It has been shown that below the critical micellar concentration (CMC), cationic, anionic and non‐ionic surfactants have no effect, while above the CMC only cationic soaps have an effect, lowering both the rate of polymerization and the molecular weight of the resultant polymer.
Copolymerization of 4‐methyl‐1,3‐dioxene‐4 with maleic anhydride and terpolymerization with styrene as the third component
Authors: Kawai Wasaburo
Published: April 2003

Copolymerization of 4‐methyl‐1,3‐dioxene‐4 with maleic anhydride was carried out. The monomer reactivity ratio was determined to be r1 = 0.18, r2 ∼ 0 in terminal model and r1 = 0.015, r1′ = 0.224, r2′ = r2′ = 0 in the penultimate model.

Calculations of run number, linkage probabilities, and number‐average chain length in the terminal model and comparison of n (mole ratio of each monomer unit content in copolymer) in each model with the experimental value was made. From these results, the obtained polymer was confirmed to be alternating. Terpolymerization of 4‐methyl‐1,3‐dioxene‐4 with maleic anhydride and styrene was also carried out. The agreement of the experimental value (titration by indicator or electroconductivity) of maleic anhydride content with the theoretical value confirms that the terpolymer has a DMS triad sequence.
Synthesis of ordered copolyamides by the interfacial polycondensation of the hydrolyzate of bisimidazoline with diacid chloride
Authors: Kagiya Tsutomu , Izu Masatsugu , Matsuda Takehisa , Matsuda Moriyasu , Fukui Kenichi
Published: April 2003

Ordered copolyamides were prepared by the interfacial polycondensation of the hydrolyzate of bisimidazoline in the aqueous solution with diacid chloride in chloroform solution; bisimidazolines used were 1,4‐bis(imidazoline‐2‐yl)butane and 1,4‐bis(imidazoline‐2‐yl)‐octane; diacid chlorides used were adipoyl chloride, sebacoyl chloride, and terephthaloyl chloride. The aqueous solutions of the hydrolyzates of bisimidazolines were prepared by heating the aqueous solutions of imidazolines at 70°C. It was shown by infrared spectra and paper electrophoresis of the hydrolyzates that bisimidazolines were hydrolyzed to give quantitatively diamines containing amides linkages of the type H2N(CH2)2NH‐CORCONH(CH2)2NH2. The regularity in the sequence of the copolyamide of nylon 26 and nylon 2T prepared from the hydrolyzate of 1,4‐bis(imidazoline‐2‐yl)butane and terephthaloyl chloride was studied by NMR spectrometry: it was concluded that the copolyamide was highly ordered.