bluuebunny/crossref_metadata_2025 huggingface dataset:
Crystallite orientation in regenerated cellulose filaments. III. Crystallite orientation in viscose monofilaments
Authors: Warwicker J. O. , Ellis K. C.
Published: April 2003

Three sets of regenerated cellulose monofilaments have been prepared from viscose. Two were stretched while still in the xanthate form and the third was stretched after regeneration to cellulose. X‐ray orientation measurements were taken around the 101 equatorial arc of x‐ray orientation measurements were taken around the 101 equatorial arc of x‐ray diagrams of filaments with different degrees of stretch. By plotting the orientation parameter, defined as the reciprocal of the angle at half the maximum intensity, against stretch, it was found that those filaments in which strong intermolecular bonding forces existed during the application of stretch reacted differently from those in which these forces were small. The presence of a well‐developed system of intermolecular bonds during stretch is found to prevent the attainment of the maximum theoretical orientation with high stretching forces. The Kratky rodlet theory is found to fit the results, and good fits are obtained for the theoretical intensity‐distribution curves predicted from it and those found experimentally. The Hermans x‐ray orientation factor fx was calculated from theoretical distribution curves, and the results plotted against stretch confirm those obtained from the orientation parameter.
Studies in cyclocopolymerization. II. Relative rates of addition in the copolymerization of acrylonitrile with certain 1,4‐dienes
Authors: Butler George B. , Kasat Radhakrishna B.
Published: April 2003

The copolymerizations of 3,3‐dimethyl‐1,4‐pentadiene with acrylonitrile (system A) and divinyl sulfone with acrylonitrile (system B) were carried out, azobisisobutyronitrile being used as the initiator. The polymers obtained were soluble in dimethylformamide in every case. The infrared spectra of the polymers indicate there was little unsaturation. This evidence supports the theory of intra–intermolecular polymerization. The reactivity ratio parameters were determined for the above systems. For system A, r1 ≃ rc ≃ 0, r2 = 3.31. For system B, r1 = 0.364, r2 = 1.94, and rc = 0.067. These results further support the general copolymer composition equation derived by Barton, Butler, and Chapin. The intrinsic viscosities of the copolymers of divinyl sulfone with acrylonitrile indicate that divinyl sulfone acts as a chain transfer agent.
Polydisperse polymers with random trifunctional branching. II. Weight‐averaging of chosen molecular size‐dependent functions and a restatement of the approximate distribution function
Authors: Berger H. L. , Shultz A. R.
Published: April 2003

The product gzbZa is weight‐averaged over the distribution of molecular species in a polydisperse polymer possessing randomly distributed trifunctional branch points. This permits comparison between branched and nonbranched polydisperse polymers of certain physical properties that depend upon the relative degree of polymerization, z, and upon the ratio of branched to nonbranched molecule mean‐square radii, g = Rbr2/Rl2. Values of a, b, and γ (a branching index) are chosen for specific physical reasons and the computed ratios,
\documentclass{article}\pagestyle{empty}\begin{document}$ (1 - \gamma )^a \int_0^\infty {g_z ^b z^a } W_z dz/\int_0^\infty {z^{a + 1} e^{ - z} dz} $\end{document}
are tabulated. The distribution function for the polydisperse polymer possessing randomly distributed trifunctional branch points is restated in terms of a modified Bessel function of the first kind. This form is of use since properties of the Bessel function are known and the tabulated values of this function are generally available.
Proton magnetic resonance of poly(ethyl acrylate), poly(butyl acrylate), poly(ethyl vinyl ether), poly(vinyl propionate), poly(vinyl stearate), and vinyl stearate from 77°K
Authors: Merrill L. J. , Sauer J. A. , Woodward A. E.
Published: April 2003

Molecular motion in one monomeric and five polymeric materials was investigated by means of broad line nuclear magnetic resonance (NMR) measurements, the widths and second moments of the resonant absorption lines being obtained at temperatures from 77 to 280–340°K. The materials investigated were: poly(ethyl vinyl ether), poly(ethyl acrylate), poly(vinyl propionate), poly(butyl acrylate), vinyl stearate, and poly(vinyl stearate).
Application of thermogravimetric techniques to reaction kinetics
Authors: Chatterjee Pronoy K.
Published: April 2003

An easier technique for the determination of reaction constants such as order, energy of activation, and frequency factor from the thermogravimetric data has been described. The method requires two TGA curves obtained with different sample weights under similar reaction conditions. Applicability of the method to complex reactions, where simultaneous decomposition occurs, has been discussed. Reaction constants for different steps of the decomposition of calcium oxalate monohydrate are evaluated.
Isomorphism phenomena in systems containing fluorinated polymers and in new fluorinated copolymers
Authors: Natta G. , Allegra G. , Bassi I. W. , Sianesi D. , Caporiccio G. , Torti E.
Published: April 2003

High molecular weight vinyl fluoride (VF)–vinylidene fluoride (VF2) and vinyl fluoride (VF)–tetrafluoroethylene (TFE) copolymers in a wide range of compositions have been synthesized at low pressure at 25°C. with the aid of a catalytic system consisting of triisobutyl boron activated with molecular oxygen. With the same catalytic system, highly crystalline homopolymers of VF and VF2, melting above the usually reported temperatures, have been obtained. The x‐ray and thermal analyses of crystalline molecular mixtures of PVF and PVF2, as well as of VF–VF2 copolymers, have shown that in both cases the monomeric units of the two types may be present in the same crystallites, giving rise to a phenomenon very similar to the isomorphism in the case of low molecular weight substances; an analogous phenomenon was already described by some of us1 for other polymeric systems. In the actual case we have observed the isomorphism between the VF and VF2 monomeric units in all the range of compositions, both for the homopolymer mixtures and for the copolymers. The VF–TFE copolymer samples, in the range of compositions examined (0–75% in TFE) show a crystal structure essentially similar to that of PVF. Due to the fact that the crystal structure of PVF is not strictly analogous to that of PVFE, in the compositions containing 75–100% TFE units a phenomenon of isodimorphism, or isopolymorphism, probably takes place. Over a wide range of compositions of the monomeric reactant mixture, a marked tendency for formation of alternating (...ABAB...)sequences within the copolymer chains has been observed.
Polybenzoylenebenzimidazoles
Authors: Colson J. G. , Michel R. H. , Paufler R. M.
Published: April 2003

A polyamide amino acid was prepared by the solution condensation of 3,3′‐diaminobenzidine and pyromellitic dianhydride. This polymer was cast as a film and converted to a polybenzoylenebenzimidazole. The gross conversion path was elucidated by spectroscopy and was substantiated by model compound studies. A novel ladder polymer was prepared from 1,2,4,5‐tetraaminobenzene and pyromellitic dianhydride.
Effect of metal salts on polymerization. Part I. Polymerization of vinylpyridine initiated with cupric acetate
Authors: Tazuke Shigeo , Okamura Seizo
Published: April 2003

The polymerization of vinylpyridine initiated by cupric acetate has been studied. The rate of polymerization was greatly affected by the nature of the solvent. In general polar solvents increased the rate of polymerization. Polymerization was particularly rapid in water, acetone, and methanol. The initial rate of polymerization of 4‐vinylpyridine (4‐VP) in a methanol–pyridine mixture at 50°C. is Rp = 6.95 × 10−6[Cu11]1/2 [4‐VP]2 l./mole‐sec. The activation energy of initiation by cupric acetate is 5.4 ± 1.6 kcal./mole. Polymerization of 2‐vinylpyridine and 2‐methyl‐5‐vinylpyridine with the same initiator was much slower than that of 4‐VP. Dependence of Rp on monomer structure and solvent is discussed. Kinetic and spectroscopic studies led to the conclusion that the polymerization of 4‐VP is initiated by one electron transfer from the monomer to cupric acetate in a complex having the structure, (4‐VP)2Cu(CH3COO)2.
Gel permeation chromatography. III. Molecular shape versus elution
Authors: Hendrickson J. G. , Moore J. C.
Published: April 2003

Rules were evolved to predict elution of linear, branched, and polar compounds in GPC, based on testing of 130 compounds. With these rules and in tetrahydrofuran solvent, data for all but a few compounds correlated onto a single calibration line. With small molecules, elution often changed, due to hydrogen bonding to the solvent; this occurred with alcohols, acids, and some chlorinated compounds, but not with mercaptans. Branched and linear isomers usually eluted at about the same point. One may conclude that structural elements were additive in their effect on elution volume in this study.
Precise molecular weight distributions of high polymers by semiautomatic solvent extraction
Authors: Harrington Rodney E. , Pecoraro P. Garth
Published: April 2003

It has been found practical to fractionate relatively monodisperse polystyrenes of molecular weights up to 4 × 106 by using a semiautomatic solvent extraction procedure. The fractionators consist of flow‐through mixing chambers provided with settling regions for the removal of finely suspended solid material. Provision is made for accurate control of both temperature and solvent–nonsolvent ratio. Two such apparatus, operated in tandem, were used in the present work; in principle, several more stages could be employed if desired for most polymer systems. Results on polystyrenes prepared in well defined ways appear to be in good agreement with predicted distributions. Applicability to other polymer systems is discussed.
Polymers from the iterated addition of hydrogen sulfide to diolefins
Authors: Erickson John G.
Published: April 2003

This paper describes polyesters and polyamides obtained by the base‐catalyzed additions of hydrogen sulfide to α,β‐unsaturated diesters and diamides. The compounds employed were ethylene diacrylate, the diacrylate of trans‐1,4‐bis(hydroxymethyl)cyclohexane, p‐xylylene diacrylate, hydroquinone diacrylate, the diacrylate of 1,4‐butanedithiol, tetraethylene glycol dimethacrylate, 1,4‐butylene dicrotonate, 1,4‐butylene dicinnamate, methylene bisacrylamide, and m‐xylylene bisacrylamide. The polymers posses the general formula, , wherein R1 is hydrogen, methyl, or phenyl, R2 is hydrogen or methyl, R3 is an alkylene, aralkylene, or oxyalkylene group, and X is oxygen, sulfur, or the imino group. Polymers with as many as several hundred repeating units were obtained. Depending upon the structure, the products are liquids, rubbers, or solids, the polymers are obtained with vinyl or sulfhydryl termination and the efficiency of this termination is very high, as was shown by chain extension of a sulfhydryl‐terminated polymer through oxidation to a polydisulfide, $$ \rlap{‐‐} ({\rm RSS\rlap{‐‐} )}_n $$, having a molecular weight 30 times as great as that of the parent dimercaptan. The syntheses of several new monomers are described.
New high temperature polymers. I. Wholly aromatic ordered copolyamides
Authors: Preston J.
Published: April 2003

Wholly aromatic ordered copolyamides of unusually high thermal stability were prepared by the condensation of aromatic diacid chlorides with symmetrical diamines containing preformed aromatic amide units in an ordered arrangement. The preservation of order in the condensation step was assured by using interfacial or solution polymerization techniques at temperatures below 50°C. Each polymer contains units derived from aminobenzoic acids, arylene diamines, and arylene diacids. By use of para‐ and meta‐ phenylene units, eight different polymers are possible; all were prepared. Differential thermal analyses and thermogravimetric analyses showed these polymers to have melting points or decomposition temperatures in a range from 410°C. for the all‐meta polymer to 555°C. for the all‐para one. Substitution of the internal N‐hydrogens of the diamines with methyl groups or phenyl groups leads to additional ordered copolymers. Several were prepared, but their melting points were much lower than those of the parent polymers limiting their usefulness in high temperature applications. Tough pliable films were prepared from all eight unsubstituted polymers, and crystalline fibers with tenacities of ca. 6 g./den. were prepared from three of the polymers. The properties of the fibers were retained to a high degree even when determined at temperatures up to 400°C. Fibers aged at 300°C. for extended periods of time showed remarkable retention of fiber properties.
Sequence distribution of partially hydrolyzed poly(vinyl acetate)
Authors: Tubbs Robert K.
Published: April 2003

Copolymers of vinyl acetate and vinyl alcohol were studied by differential thermal analysis. The melting points of the copolymers are not a simple function of the composition, but depend on the method of preparation of the copolymers. Partial saponification of poly(vinyl acetate) with sodium hydroxide leads to high melting, ordered copolymers, while reacetylation of poly(vinyl alcohol) leads to low melting, random copolymers. Catalytic alcoholysis of PVAc yields copolymers intermediate in melting point and order. The results are treated by assuming that equal melting points indicate similar sequence length distributions of crystallizable units.
Structure–property relationships of poly(vinyl alcohol). I. Influence of polymerization solvents and temperature on the structure and properties of poly(vinyl alcohol) derived from poly(vinyl acetate)
Authors: Friedlander H. N. , Harris H. E. , Pritchard J. G.
Published: April 2003

The solubility properties of poly(vinyl alcohol) (PVA) vary with the method of preparation of the poly(vinyl acetate) (PVAc) from which it is derived. PVAc was prepared with free‐radical catalysts over a range of temperatures from −78 to 90°C. with solvents of varying chain‐transfer ability. The corresponding PVA samples varied in their resistance to dissolution in water. Their high‐resolution proton nuclear magnetic resonance spectra showed on differences in tacticity. Data on 1,2‐diol content showed only minor differences. Hence, the increase in resistance of PVA to dissolution in water arising from changes in chain‐transfer activity of the solvent used in vinyl acetate polymerization is largely attributable to a decrease in molecular weight, and the increase in resistance of PVA to dissolution in water arising from a decrease in the temperature of the vinyl acetate polymerization is largely attributable to a decrease in both long and short branches. Evidently, with polar polymers having small side groups, tacticity is not the only factor influencing property variation; that is, variations in stereoregularity influence more the crystallinity of the sample as measured by density or x‐ray methods than the ultimate crystallizability under conditions of mechanical and thermal treatment. In this regard polar polymers having small side groups differ from nonpolar polymers.
Structure–Property relationships of poly(vinyl alcohol). III. Relationships between stereo‐regularity, crystallinity, and water resistance in poly(vinyl alcohol)
Authors: Kenney J. F. , Willcockson G. W.
Published: April 2003

Structure–property relationships of poly(vinyl alcohol) have been studied by measuring the crystallinity and water resistance of films derived from samples of varying, known tacticity. Crystallinities of unannealed and annealed films were examined by means of density, infrared, and x‐ray measurements. Higher tacticity did not lead to higher crystallinity. The apparent order of crystallizability was atactic ≧ syndiotactic‐rich ≫ isotactic‐rich. Water resistance of these films was determined by measuring the swelling index at 30°C. and solubility at 70 and 130–140°C. Water resistance increases as tacticity increases, with syndiotactic‐rich PVA exhibiting the highest water resistance. Since water resistance also increases with crystallinity, both stereoregularity and crystallinity must be considered when evaluating structure–solubility relationships. Differential thermal and thermogravimetric analyses of these samples are also presented, together with a correlation of tacticity index as measured by an infrared technique with that of an NMR technique.
Catalytic polymerizations of nitrobenzene and aniline
Authors: Sigal Paul , Masciantonio Philip , Fugassi Paul
Published: April 2003

Nitrobenzene refluxed over a variety of solid catalysts near its standard boiling point of 211°C. Polymerizes to give compounds whose structure appears to be that of a triaryl amine polymer. Under similar conditions aniline gives polymers whose structure appears to be a mixture of diaryl and triaryl amine bonds.
Isothermal kinetic calorimeter applied to emulsion polymerization
Authors: Andersen H. M.
Published: April 2003

A method for the direct measurement, by means of the heat of reaction, of essentially instantaneous polymerization rates is described. The polymerization is carried out isothermally, and the evolved heat is measured electrically over short time intervals. Applied to emulsion polymerization, the technique reveals several previously unobserved features.
Periodate oxidative decrystallization of cotton cellulose
Authors: Rowland Stanley P. , Cousins Edwin R.
Published: April 2003

Cotton cellulose is decrystallized by periodate oxidation to essentially zero crystallinity index (CI) at 100% oxidant consumption. The decrease in CI is pseudo zero‐order over 60% of the reaction and consistent with a diffusion‐controlled mechanism. The attack on regions of high order is indicated to be 100% in the latter phase of oxidation and 13% in the initial phase. Data allow an estimate that approximately 60% of the structural segments of the cotton cellulose under investigation lies in highly ordered arrangements.
Cyclobutane polymers from acrylonitrile dimer
Authors: Stueben K. C.
Published: April 2003

A wide variety of polyesters and polyamides was prepared from 1,2‐ and 1,3‐disubstituted cyclobutane derivatives. In general, polyamides containing thetrans‐disubstituted cyclobutane ring were crystalline. Polyesters containing predominantly thetrans‐isomer tended to be crystalline but those containing mixtures ofcis‐transisomers were amorphous. Mechanical properties have been determined wherever possible. Appreciable yields of cyclic dimers were isolated during the preparation of certain polyesters. These cyclic dimers readily polymerized when treated with dibutylzinc. Examination of acrylonitrile dimer (1,2‐dicyanocyclobutane) by gas chromatography failed to reveal the presence of any 1,3‐dicyanocyclobutanes.
Macroreticular redox polymers. II. Further synthesis and properties of some redox polymers
Authors: Kun Kenneth A.
Published: April 2003

A series of redox polymers was prepared by the addition of different redox groups to preformed, chloromethylated macroreticular styrene–divinylbenzene copolymers. These polymers contained the hydroquinone, hydroquinonesulfonic acid, methylhydroquinone, 2,5‐dimethylhydroquinone, 2,5‐dimethylhydroquinonesulfonic acid, 2,3,5‐trimethylhydroquinone, tert‐butylhydroquinone, chlorohydroquinone, benzyl mercaptan, anthraquinone, and the pyrogallol redox groups. Thus, a set of redox polymers is available having redox potentials that may range from approximately 150 to 700 mv.
Polymerization of β‐cyanopropionaldehyde
Authors: Sumitomo Hiroshi , Kobayashi Kazukiyo
Published: April 2003

A new class of polyacetals, poly(cyanoethyl)oxymethylene, was obtained by the polymerization of β‐cyanopropionaldehyde at −78°C. with use of ionic initiators including boron trifluoride diethyl etherate, diethylzinc, triethylaluminum, and triethylaluminumtitanium tetrachloride complexes. The influence of temperature, initiator, and solvent upon the polymerization was studied. Infrared spectra of polymers obtained from different initiators are also illustrated. An attempt was made to fractionate the polymer by means of solvent extraction. The acetone‐soluble polymer is an elastomeric material having a low solution viscosity. The acetone‐insoluble, dimethylformamide‐soluble polymer obtained as a white powder was found to have extremely high solution viscosity. Some amounts of insoluble fraction could be also separated. The latter two fractions were observed to have a reasonable stability.
Stability of styrene–maleamic acid interpolymers
Authors: Minsk L. M. , Dunham K. R.
Published: April 2003

The response to heat and water of copoly(styrene–maleamic acid, ammonium salt), prepared by treatment with ammonia of the anhydride polymer in toluene suspension, is described. This polymer except for the ammonia bound by salt formation, is stable to heat within the range studied, i.e., to 100°C. The behavior of water solution is determined by the ammonia concentration. Above pH 9, the bound nitrogen remains as amide. If the pH is low, i.e., about 5, as occurs when a dried sample is dissolved in water, then rapid imidization occurs with concurrent hydrolysis. In the early stages of this conversion, imidization occurs mainly through loss of ammonia. This requires that two amide groups be adjacent. Classical imidization by loss of water also occurs, indicating that the normal‐amic acid structure is also present.
Silicon‐containing Schiff base and benzimidazole derivatives
Authors: Kovacs H. Nagy , Delman A. D. , Simms B. B.
Published: April 2003

Investigations were undertaken to obtain information for use in the development of new heat‐stable polymers. Model silicon‐containing Schiff base and benzimidazole derivatives were synthesized by reaction of p‐(triphenylsilyl)‐benzaldehyde with phenylenediamines. The structure and thermal stability of the products were studied. The reaction of p‐(triphenylsilyl)benzaldehyde and o‐phenylenediamine yielded N‐p‐(triphenylsilyl)benzylidene‐o‐phenylenediamine which readily oxidizes to form 2‐p‐(triphenylsilyl)phenylbenzimidazole. The di‐Schiff bases, which most probably exist in trans‐trans configurations, were obtained from reaction of the aldehyde derivative with m‐ and p‐phenylenediamine. In contrast to similar Schiff bases without silicon, the products are soluble in organic solvents. The good resistance of the di‐Schiff base and benzimidazole derivatives to thermal decomposition suggests that polymers with repeating units of such structures would also be heat‐stable and might possess useful properties.
Base‐catalyzed polymerization of maleimide and some derivatives and related unsaturated carbonamides
Authors: Kojima Kuniharu , Yoda N. , Marvel C. S.
Published: April 2003

Basic catalysts in dimethylacetamide solution initiated the polymerization of maleimide to yield a low molecular weight polymer which has a copolymer structure. Approximately 75–85% of the recurring units are formed by hydrogen transfer and 15–25% by vinyl polymerization, as shown by hydrolysis, to yield aspartic acid on the one hand and ammonia and polymaleic acid on the other. Several maleimide derivatives have been prepared, but none has given a high molecular weight polymer by basic catalysis. Some unsaturated carbonamides such as p‐vinylbenzamide, mono‐N‐acrylyl‐hexamethylenediamine, and mono‐N‐acrylyl‐p‐phenylenediamine have been synthesized and polymerized by basic catalysts. Polymers with low molecular weights were obtained, but the complete structures of all these polymers were not established.
Graft polymerization kinetics of acrylamide initiated by ceric nitrate–dextran redox systems
Authors: Wallace R. A. , Young D. G.
Published: April 2003

The kinetics of the graft polymerization of acrylamide initiated by ceric nitrate—dextran polymeric redox systems was studied primarily at 25°C. Following an initial period of relatively fast reaction, the rate of polymerization is first‐order with respect to the concentrations of monomer and dextran and independent of the ceric ion concentration. The equilibrium constant for ceric ion—dextran complexation K is 3.0 ± 1.6 l./mole, the specific rate of dissociation of the complex, kd, is 3.0 ± 1.2 × 10−4 sec.−1, and the ratio of polymerization rate constants, kp/kt, is 0.44 ± 0.15. The number‐average degree of polymerization is directly proportional to the ratio of the initial concentrations of monomer and ceric ion and increases exponentially with increasing extent of conversion. The initial rapid rate of polymerization is accounted for by the high reactivity of ceric ion with cis‐glycol groups on the ends of the dextran chains. The polymerization in the slower period that follows is initiated by the breakdown of coordination complexes of ceric ions with secondary alcohols on the dextran chain and terminated by redox reaction with uncomplexed ceric ions.
Studies on poly(aquahydroxychromium diphenylphosphinate)
Authors: Delman A. D. , Kelly J. , Mironov J. , Simms B. B.
Published: April 2003

The novel inorganic polymer poly(aquahydroxychromium diphenylphosphinate) was investigated to obtain information concerning its degree of polydispersity and properties when dissolved in organic solvents. Viscometric, infrared absorption spectroscopic, and electrical conductimetric techniques were employed to ascertain the characteristics of the polymer dissolved in benzene, chlorobenzene, and chloroform. Gel permeation chromatography was used to determine the degree of heterogeneity of the polymer. Results indicate that the polymer, as prepared, is quite polydisperse. The polymer main chains do not undergo radical reactions with the solvents. High values of the Huggins interaction constant K′ suggest that polymer–solvent association reactions involving chain‐endgroups are probable. Such reactions are also indicated by association constant values and by the shapes of phoreograms obtained from electrical conductance data. Both “local” and “bulk” solvent properties, such as the dielectric constant, appear to influence the characteristics of the polymer when dissolved in the different solvents.
Anionic oligomerization of methacrylonitrile
Authors: Feit Ben‐Ami , Heller Eri , Zilkha Albert
Published: April 2003

The anionic oligomerization of methacrylonitrile by alcoholic solutions of sodium alkoxide in dimethyl sulfoxide, methanol and ethanol was studied. The DP of the oligomers was directly proportional to the monomer concentration and inversely proportional to the alcohol concentration, in accordance with the equation DP = K[MAN]/[ROH], K being equal to Kp/Ktr. The value of K in DMSO (with sodium methoxidemethanol) was 2.9 ± 0.2, in methanol was 1.5 ± 0.1, and in ethanol (with sodium ethoxide as initiator) was 1.9 ± 0.1. The physical properties of the oligomers are given.
Initiation and propagation in γ‐radiation‐induced polymerization of ethylene
Authors: Machi Sueo , Hagiwara Miyuki , Gotoda Masao , Kagiya Tsutomu
Published: April 2003

The initiation and propagation reaction in γ‐ray‐induced polymerization of ethylene was studied by the two‐stage irradiation method, i.e., a first stage in which initiation and propagation occur at a high dose rate, and a second stage where only the growth of polymer radical occurs. The rate of initiation is calculated from the amount of polymerized monomer and the degree of polymerization as the rate of increase in the number of polymer chains. The initiation rate is shown to be proportional to the ethylene density in the reactor and dose rate.GRof radical formation is found to be about 1.6 at 30°C. at a dose rate of 2.5 × 104rad/hr. and is almost independent of ethylene density but decreases slightly with increasing irradiation dose rate. The lifetime of the growing polymer chain radical is shown to be long at normal temperature. The absolute propagation rate is proportional to the square of ethylene fugacity and depends on dose rate to some extent. For chain growth, irradiation of low dose rate is necessary. The apparent activation energy for the propagation reaction is −9 kcal./mole.
Interactions of inorganic salts with poly(ethylene oxide)
Authors: Lundberg R. D. , Bailey F. E. , Callard R. W.
Published: April 2003

Evidence is presented for the interaction of metal salts such as potassium iodide with polyethers such as poly(ethylene oxide). This interaction is sufficiently marked that the incorporation of 10–30% of the salt in the bulk polymer markedly reduces crystallinity while retaining compatibility. Examination of electroviscous effects in methanol demonstrates that the salt–polymer adduct behaves as a typical polyelectrolyte at low salt concentrations, while the polymer in absence of salt is essentially insoluble in methanol at room temperature. Measurements of the equilibrium between salt and polymer along with a study of various molecular weight polymers strongly suggest that one salt molecule associates with about nine ethylene oxide units. It is proposed that the association is due to an ion–dipole interaction, and the anion is tentatively postulated as the species directly associating with the polymer. The association of other metal salts and other polymers are interpreted in this light. The significance of these results in interpreting salting‐in phenomena is also discussed.
Cationic graft copolymerization of styrene onto chlorinated butyl rubber
Authors: Minoura Yuji , Hanada Takeshi , Kasabo Toshiyuki , Ueno Yukio
Published: April 2003

The graft copolymerization of styrene onto chlorinated butyl rubber (Cl‐IIR) with stannic chloride as cationic catalyst was studied in cyclohexane, and the rate of polymerization, per cent grafting and grafting efficiency were obtained. Polymerization was carried out in a sealed tube. The product was precipitated in methanol and dried. The increase in weight of Cl‐IIR used was regarded as styrene conversion, and the increase in weight after extraction by boiling acetone as the weight of grafted styrene. Grafting was confirmed by fractional dissolution and infrared spectra. The rate of polymerization of styrene was proportional to concentrations of styrene, Cl‐IIR and SnCl4. The per cent grafting increased with styrene and SnCl4 concentration, but was constant with Cl‐IIR concentration. It also increased with time and with halogen content in the polymer. The addition of a polar solvent such as nitrobenzene greatly promoted the grafting reaction and the per cent grafting was 200%.
Zinc oxide‐sensitized photopolymerization
Authors: Yamamoto Masahide , Oster Gerald
Published: April 2003

Zinc oxide under ultraviolet excitation causes the polymerization of vinyl monomers if water and oxygen are present. Analysis shows that hydroxyl radicals initiate the chain. Hydrogen peroxide is produced with light‐excited zinc oxide and is further decomposed by the reducing action of excited zinc oxide.
Ordered structures of styrene–butadiene block copolymers
Authors: Vanzo Ed
Published: April 2003

Anionically prepared block copolymers of butadiene and styrene exhibit solution properties which result from a two‐dimensional ordering of the polymer molecules. The most notable of these properties is the iridescent colors of toluene solutions which are dependent on concentration and abruptly change on mechanical deformation. Electron micrographs of the surface of cast films indicate that the ordered structure is retained to some degree in the solid state.
Studies on polymers containing functional groups. II. Polymerization behavior of o‐hydroxystyrene
Authors: Kato Masao , Kamogawa Hiroyoshi
Published: April 2003

The polymerization behavior of o‐hydroxystyrene with free‐radical and cationic initiators and without an initiator was examined. The structures thus obtained were estimated. Although polymerization behavior of o‐hydroxystyrene was rather complicated, according to the results, it appeared that each polymerization more or less might simultaneously follow the two types of mechanisms: normal vinyl polymerization and polymerization through the addition to benzene nuclei. The proportion of addition to benzene nuclei was considered to be highest in the polymerization with BF3·(OEt)2 and lowest in that with azobisisobutyronitrile. Degrees of polymerization of these polymers were low in all cases (42–82). Some brief experiments on copolymerization of o‐hydroxystyrene were carried out.
Donor–acceptor interactions in cationic polymerization. VII. Relationship between the degree of dissociation of complex and the molecular weight of polyisobutylene formed in the presence of some complexes of aluminum trichloride with electron donors
Authors: Zlámal Z. , Kazda A.
Published: April 2003

The concentration dependence of the specific conductivity of the complexes of aluminum trichloride with dibutyl ether, anisole, phenol, and diphenyl ether at equimolar ratios of the two compounds has been measured. Conductivity measurements have been carried out in ethyl chloride at −78.5°C. Except for dibutyl ether, all the complexes studied are associated over the whole concentration range and their degree of dissociation and molar conductivity are independent of the concentration. In the case of the BuOBu·AlCl3 complex these quantities begin to be independent of the concentration only at concentrations higher than 20 mmoles/l. The degree of polymerization or the molecular weight of polyisobutylene formed by the polymerization in the presence of given complexes is inversely proportional to the concentration of the anions present. This is especially evident from the fact that the relation between x and 1/M̄ is also linear in the case of the BuOBu·AlCl3 complex, whose degree of dissociation and therefore molar conductivity varies distinctly with the concentration of the complex. The comparison of the chain‐breaking efficiency of the anions derived from phenol and diphenyl ether with those derived from phenetole and anisole shows that the mixed aryl alkyl ethers split after reacting with aluminum trichloride under these conditions, so that the phenyl group becomes a part of the cation and the alkyl group a part of the anion. On the basis of the different behaviors of the ions and the dipoles, the differences in the dependence of the degree of polymerization on the dielectric constant of the medium in the cationic polymerization have been explained.
Studies on Ziegler‐Natta catalysts. Part V. Stereospecificity of the active center
Authors: Rodriguez L. A. M. , van Looy H. M.
Published: April 2003

Experimental results on Ziegler‐Natta catalysts, based on observations made with the electron microscope, and a qualitative comparison of the stereospecificity of various catalyst combinations are given. The polymerization of olefin in these experiments is performed in the gas phase on dry catalysts in the absence of solvent or excess aluminium alkyl. The crystallographic structure of the lateral faces of α‐TiCl3 is established by electron microscopy and electron diffraction. The electron micrographs of α‐TiCl3–AlMe3 catalysts show that the active centers, which are revealed by the dotwise formation of polymer, are located along the growth spirals, on lateral faces, and on surface defects. These regions of the surface are the only regions in which the surface titanium atoms are incompletely coordinated. The presence of chlorine vacancies and exposed titanium atoms is therefore an essential condition for the formation of active centers. However, the number of active centers is small in comparison to the number of incompletely coordinated titanium atoms, and hence it is concluded that the normally occurring α‐TiCl3 sites with one vacancy do not yield active centers on reaction with aluminum alkyl. It is proposed that the reaction with aluminum alkyl on such sites leads ultimately to a bimetallic complex which fills the original vacancy on the titanium atom. That the complexation is reversible and that the deblocked alkylated site, which is of the type proposed by Cossee, is an active center is not excluded. Such a center would, however, give atactic polymer. Similar complex formation on a TiCl3 site having originally two vacancies would leave one vacancy on the titanium atom. This is believed to be the center of stereospecific polymerization. A model of this active center and a mechanism of polymer growth on it are proposed.
Preparation and polymerization of some vinyl ester amides of pinic acid
Authors: Griffith J. H. , Marvel C. S. , Hedrick G. W. , Magne Frank
Published: April 2003

The preparation of vinyl 2,2‐dimethyl‐3‐morpholinocarbonylcyclobutaneacetate, vinyl 2,2‐dimethyl‐3‐piperidinocarbonylcyclobutaneacetate, and vinyl 2,2‐dimethyl‐3‐di‐n‐butylaminocarbonylcyclobutaneacetate has been achieved by selective amination followed by vinyl interchange. Homopolymers and vinyl chloride copolymers containing 25 and 30 wt.‐% of the vinyl esteramides were prepared and evaluated as nonrigid plastics. The vinyl esteramides incorporated in vinyl chloride copolymers did impart some plasticization, but their effect was far below the effect of added plasticizer to a vinyl chloride polymer.
Flow rates of polymer solutions through porous disks as a function of solute. I. method
Authors: Rowland Fred W. , Eirich Frederick R.
Published: April 2003

A method for studying the thickness of adsorbed polymer films, based on the reduction in effective cross section for liquid flow caused by the deposition of such a film on the interior of a capillary, is described. A sintered disk is used instead of a single capillary to raise the flow rate to an easily measured level, to avoid the difficulties of obtaining or fabricating the extremely fine capillaries which would be required, and to eliminate the extreme precautions needed to prevent plugging of a single capillary. Techniques for characterizing the sintered disks are presented. When applied to benzene solutions of stearic acid and of polystyrene, film thicknesses of 30 and 312 A., respectively, were obtained. This is in good agreement with present knowledge of fatty acid adsorption, and suggests that the polymer is adsorbed in a highly extended configuration. The application of this method to solutions of poly(vinyl acetate), poly(methyl methacrylate), and polystyrene in several solvents at various temperatures is described in a following paper.
Radiochemical determination of low unsaturations in polyisobutene
Authors: McGuchan R. , McNeill I. C.
Published: April 2003

A radiochemical technique involving the use of 36Cl has been described previously for the measurement of butyl rubber unsaturations. This method has now been applied to the estimation of the much lower concentration of double bonds present in polyisobutene prepared by the cationic polymerization of isobutene at a low temperature. The nature of the reaction of polyisobutene with radiochlorine in the absence of air is examined, and the experimental results are discussed in relation to present theories of the mechanisms of chain termination in cationic polymerization.
Ferrocene‐containing polymers. XIII. Polymeric compounds possessing carboxyphenyl side groups
Authors: Neuse Eberhard W. , Koda Kazuko
Published: April 2003

As an extension of earlier work on the condensation of ferrocene with aldehydes, the polycondensation of ferrocene with p‐ and o‐carboxybenzaldehyde is described. While, in the former case, regular polycondensation occurs giving rise to a polymer composed of ferrocenylene and 4‐carboxybenzal units, a deviation from this route is observed in the o‐carboxybenzaldehyde case, where a polymer containing both carboxybenzal and 3,3‐phthalide bridging units between the ferrocenylene groups is formed instead. This unexpected behavior can be accounted for by a hydride abstraction mechanism. In support of the polymer structure proposed, 3‐ferrocenylphthalide and 3,3‐diferrocenylphthalide are isolated as intermediates or by‐products. In both polymer series, number‐average molecular weights up to 3000 (unsubfractionated) are measured. The polymers are soluble in a number of organic solvents and can be cured with epoxides.
Influence of addition of ethylene on the γ‐ray‐induced alternating copolymerization of ethylenimine and carbon monoxide
Authors: Kagiya Tsutomu , Narisawa Shizuo , Ichida Taizo , Fukui Kenichi , Yokota Hisao
Published: April 2003

The influence of the addition of ethylene on the γ‐ray‐induced alternating copolymerization of ethylenimine and carbon monoxide was investigated. A mixture of ethylenimine, carbon monoxide, and ethylene was irradiated to produce a polymer containing these monomeric units. The infrared spectrum of the copolymer showed the characteristic absorption peaks of the secondary amide and ketone bond and was different from that of the reaction product of polyketone with ethylenimine and that of the γ‐ray irradiation product of ethylene and poly‐ß‐alanine. The x‐ray diffraction diagram of the copolymer was different from those of poly‐ß‐alanine and polyketone and exhibited an amorphous structure. Paper chromatographic analysis showed that the hydrolysis product of the copolymer contained ß‐alanine and δ‐aminovaleric acid. These results indicate that terpolymerization of ethylenimine, carbon monoxide, and ethylene took place under γ‐ray irradiation and gave an amorphous polymer containing the units
\documentclass{article}\pagestyle{empty}\begin{document}$ \rlap{} ({\rm CH}_{\rm 2} {\rm CH}_{\rm 2} {\rm NHCO}\rlap{}),\rlap{} ({\rm CH}_{\rm 2} {\rm CH}_{\rm 2} {\rm CO}\rlap{}),{\rm and}\rlap{} ({\rm CH}_{\rm 2} {\rm CH}_{\rm 2} {\rm CH}_{\rm 2} {\rm CH}_{\rm 2} {\rm NHCO}\rlap{}) $\end{document}
Studies on anionic polymerization of lactams. Part II. Effect of cocatalysts on the polymerization of pyrrolidone
Authors: Barzakay S. , Levy M. , Vofsi D.
Published: April 2003

The rates of addition of pyrrolidonate magnesium bromide (PyMgBr) to N‐benzoyl‐, N‐acetyl‐, and N‐methylpyrrolidone were measured in solution in tetrahydrofuran (THF). The values found for the rate constants at 25°C. were 9.5 × 10−2, 2.8 × 10−2, and 5 × 10−4 l./mole‐sec., respectively. The rate constant for addition of PyMgBr to pyrrolidone was also measured and found to be 3 × 10−9l./mole‐sec. Possible causes for the large difference between the values of these constants are discussed.
Radiation‐induced polymerization of hexafluoropropylene at high temperature and pressure
Authors: Lowry R. E. , Brown D. W. , Wall L. A.
Published: April 2003

The radiation‐induced polymerization of hexafluoropropylene was studied in the pressure and temperature ranges of 4,500–15,000 atm. and 100–230°C., respectively. Retardation was a serious problem; data thought to apply to the unretarded polymerization are summarized below. At 1,500 rad/hr. the polymerization rate was 15%/hr. at 230°C. and 15,000 atm. The activation enthalpy and volume are 9.5 kcal./mole and −10 cc./mole, respectively. The rate varies as the square root of the radiation intensity. The largest intrinsic viscosity of the polymer is 2.0 dl./g.; values increase with temperature and pressure. At 130°C. and 10,000 atm. the intrinsic viscosity was the same at two radiation intensities.
Radiation‐induced solid‐state polymerization in binary systems. II. Relationship between polymerization rate and physical structure of binary systems
Authors: Kaetsu Isao , Sagane Norio , Hayashi Koichiro , Okamura Seizo
Published: April 2003

The radiation‐induced solid‐state polymerization of binary systems consisting of acrylic monomer (acrylamide, acrylic acid) and organic compounds was investigated. In the previous paper on binary systems the authors reported that the rate of polymerization increased in the solid state (eutectic mixture systems). The mechanism of rate increase has been investigated by examination of phase diagrams, viscosities, and surface tension of the binary systems. Viscosity and surface tension are the measure of the molecular interaction of the two‐component systems. In addition, the effect of linear crystal growth rate and half maximum width of the x‐ray diffraction diagram of the crystallization process were determined. The larger the molecular interaction between the two components, the slower the linear crystal growth rate of monomer. The size of the monomer crystal decreases and the dislocation density of the monomer crystals increases in systems with large molecular interaction. Consequently it can be concluded that the physical structure of a binary solid system is the most important parameter determining the rate increase of solid‐state polymerization. Dislocation on the grain boundary is more important than defects inside of the crystal lattice. It was found that the acceleration of polymerization rate is large in binary systems with larger molecular interaction. In some systems such as organic acid—amide systems with strong hydrogen bonds, glassy phases may be formed in which monomer may readily polymerize at very low temperatures.
Hydroformylation of high polymers
Authors: Ramp Floyd L. , Dewitt Elmer J. , Trapasso Louis E.
Published: April 2003

A new class of polymeric materials has been prepared and subjected to preliminary evaluation. These materials were obtained by hydroformylation of diene‐based polymers. The olefinic bonds were saturated and aldehyde groups attached.
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The extent of reaction may be varied at will up to 100% double bond conversion. The properties of these polymers are dominated by the active aldehyde groups. One of the chief characteristics of simple aldehydes is their ability to polymerize forming mainly aldehyde trimers and tetramers. This same phenomenon has been shown to occur with polymeric aldehydes with consequent gel formation. The gelling tendency has been closely related to the aldehyde content per unit volume which may be conveniently varied by (1) the concentration of the initial polymer, (2) the degree of unsaturation in the polymer, and (3) the extent of double bond conversion. Any combination which gives a free aldehyde concentration in excess of 1 × 10−4 mole/ml. is very prone to gel. The loose gels can be readily reversed by conditions which depolymerize aldehydes. The propensity of the aldehyde polymers to crosslink upon evaporation of the solvent was used to form films. These films were not discolored by ultraviolet light but under such treatment became quite brittle. The products may be stabilized by conversion of the aldehyde groups to more stable derivative, in particular the acetal. The extent of acetal formation has been shown to be controlled by steric factors. Complete polyacetal formation was possible only when the aldehyde groups were well dispersed along the polymer chain. Certain aldehyde derivatives (acetals, oximes) are thermoplastic. They soften at lower temperature than commercial plastics.
Kinetics of amylose retrogradation
Authors: Doppert H. L. , Staverman A. J.
Published: April 2003

This article deals with the kinetics of the retrogradation of amylose in aqueous solutions of pH 4.0, 9.2, and 11.9. The course of the retrogradation is followed by means of light‐scattering measurements. From our interpretation of the light‐scattering data we conclude that the retrogradation mechanism appears to be in qualitative agreement with von Smoluchowski's theory on coagulation. From the rate of retrogradation one may tentatively conclude that only a small fraction of the collisions between the amylose aggregates leads to permanent coagulation. In order to explain this phenomenon, additional conditions are suggested for permanent attachment of two colliding aggregates. The relevant fraction is smaller at pH 11.9 than at the lower pH's, a fact which is ascribed to the mutual repulsions of the aggregates due to their negative charges.
Polyelectrolytic character of amylose. II.
Authors: Doppert H. L. , Staverman A. J.
Published: April 2003

Viscometric titrations of amylose are described. The curves confirm the earlier results of Rao and Foster. A more quantitative consideration is given concerning the changes of the electrostatic charge of the amylose molecules in the pH range of 11–12, where a minimum in the titration curve is found. A viscometric titration performed in solutions containing urea shows a considerably higher viscosity, especially at lower pH's; the curve, however, still shows a minimum between pH 11 and 12. Experiments on the dependence of [η] on the ionic strength at pH 12.7 also demonstrate the typical polyelectrolytic nature of amylose.