bluuebunny/crossref_metadata_2025_split huggingface dataset:
Radiation‐induced emulsion polymerization of ethylene. I. Effect of reaction conditions on the polymerization
Authors: Senrui Shiro , Suwa Takeshi , Konishi Kunio , Takehisa Masaaki 
Published: April 2003

AbstractThe effect of reaction conditions on the rate of radiation‐induced emulsion polymerization of ethylene was studied by use of a 500‐ml autoclave. Among various kinds of emulsifiers, a series of potassium salts of fatty acids gave high rates of the polymerization. The polymerization was inhibited by the presence of oxygen, but the rate of polymerization followed by the induction period was not influenced by the initial presence of oxygen. Stirring rate and the monomer: water ratio did not affect the rate of polymerization. The rate of polymerization was maximum at about 80°C, and number‐average molecular weight was influenced by the temperature in a similar manner as the rate of polymerization. This suggests that the change of mobility of propagating radical in the polymer particle changes the rate of termination reaction. The rate of polymerization was proportional to the 1.7 power of the reaction pressure.
Copolymerization of carbon dioxide with propyleneimine
Authors: Soga Kazuo , Chiang Wen‐Yen , Ikeda Sakuji 
Published: April 2003

AbstractCarbon dioxide and propyleneimine were allowed to copolymerize without using any catalyst to give a polyurethane with a carbon dioxide content of 10–35 mole‐%. The polymer yield, the specific viscosity, and the content of carbon dioxide in the copolymer increased with increasing polymerization temperature. The infrared spectrum of the copolymer showed the characteristic peak assignable to a cyclic urethane(4‐methyl‐oxazolidone‐2) at 1750 cm−1 as well as the peak characteristic of the urethane linkage at 1700 cm−1. The relative intensity ratio of the former absorption to the latter decreased markedly with increasing polymerization temperature. Propyleneimine did not polymerize at all in the absence of carbon dioxide. Polymerizations were also carried out with the use of various solvents. On the basis of these results, a probable reaction scheme of the copolymerization was proposed.
Imidization during polymerization of acrylamide
Authors: Minsk L. M. , Kotlarchik C. , Meyer G. N. , Kenyon W. O. 
Published: April 2003

AbstractThe spontaneous imidization of acrylamide during polymerization has been studied in three media: benzene, diglyme, and water. The data indicate that neither medium, time, nor temperatures below 140°C cause imidization to occur. The ascription of the low nitrogen found in polyacrylamide by some investigators to imide formation appears to be in error. The low nitrogen is due rather to retained solvent and/or water, for which polyacrylamide has a strong affinity. Imidization may be brought about by strong acids. The solubility of an imidized polyacrylamide decreases with increasing imide content.
Anionic polymerization of phenyl vinyl ketone initiated with a model compound possessing the same structure as the growing chain end
Authors: Tsushima Rikio , Tsuruta Teiji 
Published: April 2003

AbstractAnionic polymerization of phenyl vinyl ketone (PVK) was carried out in toluene at 0°C by use of an initiator, ethylzinc 1,3‐diphenyl‐1‐pentene‐1‐olate (I), which possesses the same structure as the growing chain end of PVK in the diethylzinc (ZnEt2)‐initiated polymerization. A unimodal molecular weight distribution was found in the obtained polymer. The polymerization system exhibited a “living characteristic” with the initiator efficiency being 1.0.
Temperature dependence on the binding of butyl orange by bovine serum albumin
Authors: Takagishi Toru , Takami Katsushige , Kuroki Nobuhiko 
Published: April 2003

AbstractThe binding of 4′‐dibutylaminoazobenzene‐4‐sulfonate anion (butyl orange) by bovine serum albumin has been examined quantitatively by an equilibrium dialysis method at 5, 10, 15, 20, 25, and 35°C. The first binding constants and the thermodynamic parameters for the formation of the first dye anion‐protein complex have been calculated. The peculiar temperature dependence of the first binding constant could be observed. That is, the value of the first binding constant increases with increasing temperature until it reaches a maximum value at approximately 18°C and then decreases with raising temperature. Accordingly, this binding process is exothermic above 18°C and is endothermic below 18°C. Near 18°C the process exhibits athermal reaction. From the thermodynamic data obtained, it is evident that the favorable free energy of the binding is accompanied by an entropy gain and that the enthalpies of the binding vary from a positive (unfavorable) value below 18°C to a negative (favorable) one above 18°C. Furthermore an apparent temperature dependence of the thermodynamic functions was observed. That is, ΔF° becomes larger in absolute magnitude as the temperature increases. The positive quantity of ΔS° tends to decrease with increasing temperature. All these facts can be interpreted satisfactorily in terms of hydrophobic interactions between hydrophobic portions of the dye and nonpolar parts of the albumin.
Studies on the photooxidation mechanism of polymers. II. The role of quinones as sensitizers in the photooxidative degradation of polystyrene
Authors: Rabek Jan F. , Rånby Bengt 
Published: April 2003

AbstractDuring the quinone‐sensitized photooxidative degradation of polystyrene film and its solution in benzene, an initial rapid decrease of average molecular weight has been observed by GPC and viscosity measurements. The reaction rates are strongly increased by quinones such as p‐quinone, duroquinone, anthraquinone, and chloranil. It has been suggested that this photosensitized degradation of polystyrene occurs by a singlet oxygen reaction which might be related to an energy transfer mechanism from excited triplet states of quinones to molecular oxygen. The photooxidative degradation of polystyrene in solution can be diminished by addition of typical singlet oxygen quenchers such as 1,3‐cyclohexadiene or β‐carotene.
Preparation and properties of polymers with biphenyl units in the chain: Syntheses of solvent‐soluble substituted polyphenylenes
Authors: Hayama Shigeru , Niino Shogo 
Published: April 2003

AbstractBenzidinetetrazonium chloride (BTC)–CuCl and BTC–FeCl2 complexes were thermally converted to benzene‐soluble poly‐4,4′‐biphenylene plus small amounts of insoluble material. The soluble fraction was more stable than the insoluble fraction when heated at 300–500°C, although the solubility decreased. BTC in water was converted to an insoluble material by addition of alkali or cuprous ammonia solution. The C/(H + Cl) ratio indicated the existence of three to five side groups for each twenty phenyl groups of the insoluble fraction, while that of the soluble fraction showed few such groups. The number increased to one or more side groups for each phenyl nucleus as both soluble and insoluble fractions were heated to 500°C. A thin film of soluble fraction deposited on a copper plate showed an electrical conductivity in the range 10−2–10−3 ohm−1 cm−1 at 25°C and an energy gap (ΔEg) of 0.2–0.3 eV. However, a compressed specimen of the same soluble fraction showed little conductivity. Solventsoluble samples of substituted poly‐4,4,‐biphenylene were prepared by the same procedure. These materials cracked on processing, and accurate conductivity measurements could not be made.
Kinetics of radiation‐induced bulk polymerization of vinyl chloride in the temperature range of −50 to 90°c
Authors: Tavan M. , Palma G. , Carenza M. , Brugnaro S. 
Published: April 2003

AbstractKinetic investigations on the bulk polymerization of vinyl chloride initiated by exposure to 60Co γ‐rays were carried out in the temperature range of −50 to 90°C at dose rates varying from 0.15 to 50 rad/c. Some polymerization runs were also carried out in a centrifugal field. As generally reported for this polymerization system, in which the polymer is insoluble in the monomer, the polymerization rate was found to change as a function of the amount of the polymer formed in a special fashion. This particular function has been shown to be greatly influenced by the polymerization temperature and to be independent of the rate of initiation, or, more rigorously, of the dose rate. Thus, at any given temperature the equation of the polymerization conversion rate could be written in the form of the product of two separate functions, one for the polymerization conversion and the other for the dose rate. While for the latter the results gave an essentially square‐root dependence on dose rate as is normally found for homogeneous polymerization, the former has been discussed in the terms of recently advanced kinetic schemes, based on a two‐phase polymerization model. The kinetic parameters found in this work are in agreement with previous authors' data.
Synthesis and characterization of polyaryloxyphosphazenes
Authors: Singler R. E. , Hagnauer G. L. , Schneider N. S. , Laliberte B. R. , Sacher R. E. , Matton R. W. 
Published: April 2003

AbstractThe synthesis, dilute solution characterization, and thermal analysis of seven polyaryloxyphosphazenes are described. Synthesis is accomplished by the ring‐opening polymerization of hexachlorocyclotriphosphazene at 245°C, followed by reaction of polydichlorophosphazene with sodium aryloxide salts in solution at 115°C. Polymers prepared and characterized have the general structure [(ArO)2PN]n, with Ar = C6H5, m‐ and p‐CH3C6H4, m‐ and p‐ClC6H4, p‐C2H5C6H4, or p‐CH3OC6H4. Elemental and infrared analyses show these polymers are essentially free of reactive chlorine sites. All the polymers displayed high intrinsic viscosities [η] > 1 dl/g, in tetrahydrofuran or chloroform. Closer examination of the dilute solution properties of two polyaryloxyphosphazenes revealed high molecular weights (M̄w> 6 × 105) and broad molecular weight distributions (M̄w/M̄n > 4.7). The experimental values for the Z‐average radii of gyration, 〈S2〉z1/2, characterized at near theta conditions, are larger than the calculated values for a freely rotating chain, which suggests that these polymers are relatively linear and not highly branched. Thermal analysis revealed second‐order glass transitions between −37 and +13°C and first‐order endothermic transitions between 43 and 160°C for the different polymers. Although crystalline structure can persist above this first‐order transition, this temperature can be regarded as a melting temperature or softening temperature at which films can be molded. Decomposition temperatures, measured in argon and oxygen, ranged from 250°C to 400°C.
Availability and disposition of hydroxyl groups on surfaces of crystalline cellulose II
Authors: Rowland Stanley P. , Roberts Earl J. , French Alfred D. 
Published: April 2003

AbstractThe relative availabilities of hydroxyl groups at C(2), C(3), and C(6) on the D‐glucopyranosyl units of a particular, highly ordered hydrocellulose II have been studied by means of the reaction of N,N‐diethylaziridinium chloride, which introduces 2‐(diethyl‐amino)ethyl substituents. The hydrocellulose II was formed by hydrolysis of fibrous cotton cellulose II during 40 min reflux in 2.5M hydrochloric acid and is designated EHC‐II (exemplar hydrocellulose II) because it represents the most highly ordered (crystalline) particles in a series of hydrocelluloses. The deviation in the distribution of substituents among the 2‐O‐, 3‐O‐, and 6‐O‐ positions of the D‐glucopyranosyl units in EHC‐II from that in a disordered cellulose, in which the three types of hydroxyl groups are equally available, is the basis for estimated availabilities of the three types of hydroxyl groups on the surfaces of elementary fibrils in EHC‐II. The experimental values of relative availabilities of O(2)H:O(3)H:O(6)H for EHC‐II were 1.0:0.26:0.72 compared to estimated values of 1.0:0.0:.075 for surfaces of elementary fibrils of an idealized, perfectly ordered cellulose II, a model that is based on intensities of x‐ray diffraction peaks.
Modification and characterization of polystyrene surfaces used for cell culture
Authors: Matsuda Takehisa , Litt Morton H. 
Published: April 2003

AbstractSurfaces of polystyrene Petri dishes used for cell culture were chemically modified by 5% fuming sulfuric acid. The sulfonation was performed at room temperature for various times. Formation of polar groups takes place essentially on the surface of the polymer. Wettability and ionic character of the modified surfaces were determined by contact angle measurements and surface conductivity measurements, respectively. Radioactive calcium (45Ca) adsorption at these surfaces was investigated by means of radiotracer techniques. The chemical composition (concentration of polar sites produced) of these modified polystyrene surfaces was thus determined. It was found that the wettability of these surfaces is directly related to the concentration of sulfonate groups. The cation‐exchange capacity of treated surfaces with inorganic cations (Na+, Mg2+, Ca2+, and Al3+) were determined by the radiotracer technique.
Metal compounds in free‐radical processes. II. Interaction of copper (II) chelates of N‐alkylnorephedrines with peroxides and 2,2′‐diphenyl‐1‐picrylhydrazyl
Authors: Horanská V. , Bartoň J. 
Published: April 2003

AbstractThe reactions of the copper (II) chelates of norephedrine (I), N‐methylnorephedrine (II), N‐ethylnorephedrine (III), and N‐n‐butylnorephedrine (IV) with benzoyl peroxide, cumene hydroperoxide, and 2,2′‐diphenyl‐1‐picrylhydrazyl have been studied. Only the chelates of N‐alkyl‐substituted norephedrines enter into the reactions with free radicals, while their reactivity increases with the length of the alkyl substituent in the amino group of the ligand. The decomposition of cumene hydroperoxide was catalyzed by all four chelates; the catalytic efficiency increases in the order I<II<III < IV.
High temperature polymers. I.—Sulfone ether diamines as intermediates for tractable high temperature polymers
Authors: Kawakami James H. , Kwiatkowski George T. , Brode George L. , Bedwin Albert W. 
Published: April 2003

AbstractA useful synthesis of a series of new aromatic sulfone ether diamines, H2NC6H4O\documentclass{article}\pagestyle{empty}\begin{document}$\hbox{---}\hskip-5pt[\ {\rm C}_{\rm 2} {\rm H}_{\rm 4} {\rm SO}_{\rm 2} {\rm C}_{\rm 6} {\rm H}_{\rm 4} \hbox{--} {\rm ORO}\hbox{---}\hskip-5pt ]_n {\rm OC}_{\rm 6} {\rm H}_{\rm 4} {\rm SO}_{\rm 2} {\rm C}_{\rm 6} {\rm H}_{\rm 4} \hbox{---} {\rm OC}_{\rm 6} {\rm H}_{\rm 4} {\rm NH}_{\rm 2} $\end{document}, where n = 0, 1, 2…, which increases the tractability of polyimides, polyamide‐imides, and polyamides, was developed. These diamines were prepared by condensing various proportions of sodium p‐aminophenate, sodium bisphenates, and dichlorodiphenyl sulfone. The synthetic procedures are now refined to the point where simply coagulating these diamines into water yields high purity polymer‐grade sulfone ether diamines. The latter have good tractability; and in some cases, it is possible to extrude and injection‐mold these high temperature polymers.
Interaction of polyvinylpyrrolidone and iodine
Authors: Cournoyer Robert F. , Siggia Sidney 
Published: April 2003

AbstractA nonsolvent preparation of the polyvinylpyrrolidone (PVP) complex provides new insight into the nature of the polymer‐iodine interaction. The preparation is obtained by simply mixing PVP with crystalline iodine and is of interest because it provides a system in which no interfering ions are present and only one type of iodine is initially present. The iodine is shown to undergo hydrolysis with moisture in the polymer to give iodide and hypoiodite. The ionic forms of iodine appear to associate with the molecular iodine, resulting in the final stable PVP‐iodine complex.
Electron spin resonance studies of propagating radicals in polymerization. II. Acrylate propagating radicals
Authors: Harris James A. , Hinojosa Oscar , Arthur Jett C. 
Published: April 2003

AbstractFerric chloride‐photosensitized free‐radical initiation was used to generate propagating radicals in polymerization of acrylic acid (AA), methyl acrylate (MA), ethyl acrylate (EA), butyl acrylate (BA), acrylamide (A), and diacetone acrylamide (DAA) in rigid glasses of methanol, ethanol, n‐propanol, isopropanol, or acetone at near liquid nitrogen temperatures. When the temperatures of the glasses were increased, primary radicals derived from the solvents reacted with the monomers to yield propagating radicals. Formation and conformational changes of the propagating radicals at different temperatures were studied by electron spin resonance (ESR) spectroscopy. It was concluded that one type of propagating radical was formed in all cases. However, when the temperature of the rigid glass was increased, the structural conformation of the radical that initially allowed the near‐equivalent interaction of the α‐hydrogen and one of the β‐hydrogens with the unpaired electron generated a three‐line spectrum.
Epoxy/modifier block copolymers
Authors: Noshay A. , Robeson L. M. 
Published: April 2003

AbstractThe curing of epoxy resins with anhydrides in the presence of dihydroxyl‐terminated polyester or polyether modifiers produces block copolymer structures in which one “block” is the crosslinked epoxy/anhydride network and the other block is the linear modifier segment. The morphology of the cured system is dependent upon modifier molecular weight. The critical molecular weight of polycaprolactone and poly(propylene oxide) is 3000–5000. Below this level, single morphological phase systems are obtained, but two‐microphase systems result above this level. This behavior is displayed by several epoxy resins. Two‐phase systems display a superior balance of heat distortion temperature and impact strength, thus providing tough systems with greater elevated temperature capabilities than are obtained with single‐phase systems.
Synthesis of polyamides from pseudo dibenzoylphthaloyl chlorides and aliphatic diamines
Authors: Ueda Mitsuru , Ohkura Masatsugu , Imai Yoshio 
Published: April 2003

AbstractNew pseudo dibenzoylphthaloyl chlorides, namely, 2,5‐dibenzoylterephthaloyl, 4,6‐dibenzoylisophthaloyl, and 4,6‐di(p‐toluyl)isophthaloyl chlorides, were synthesized as monomers. The ring‐opening polyaddition reaction of the pseudo dibenzoylphthaloyl chlorides with aliphatic diamines in N‐methyl‐2‐pyrrolidone afforded a new class of polyamides having inherent viscosities of 0.2 ∼ 0.6 in quantitative yield. The solution polymerization was almost completed within 30 min at room temperature. All of the polyamides were soluble in a wide range of solvents including tetrahydrofuran. These polymers began to decompose at around 300°C both in air and under nitrogen as determined by differential thermal analysis (DTA) and thermogravimetric analysis (TGA).
Copolymerization of carbon dioxide and N‐phenylethylenimine
Authors: Soga Kazuo , Hosoda Satoru , Ikeda Sakuji 
Published: April 2003

AbstractCopolymerizations of carbon dioxide and N‐phenylethylenimine were carried out with the use of various catalysts and solvents. The infrared spectrum of the polymer produced showed the characteristic absorption peak at 1730–1735 cm−1 based on the urethane linkage.The content of the urethane linkage decreased in the following order: Mn(acac)2 ≈ MnCl24H2O > Al(OBu)3 > Ti(OBu)4 > ZnCl2 ≫ BF3OEt2 = VCl3 = Mn(acac)3 = FeCl3 = CrCl3 · 6H2O = 0. The manganase (bivalent) catalyst in combination with n‐hexane solvent was found to be the best system for the copolymerization, and this system received detailed study. Generally speaking, both the polymer yield and the content of the urethane linkage increased with increasing content of carbon dioxide in the feed as well as with increasing polymerization temperature. From the fractionation of polymer in methanol, it was found that the produced polymer is composed of both homopolymer of N‐phenylethylenimine and copolymer of N‐phenylethylenimine and carbon dioxide. The content of the urethane linkage of the copolymer thus fractionated was as high as about 80%.
Investigations on poly(vinyl chloride). I. Evolution of aromatics on pyrolysis of poly(vinyl chloride) and its mechanism
Authors: Iida Takeo , Nakanishi Motoharu , Gotō Kunio 
Published: April 2003

AbstractPoly(vinyl chloride) (PVC) alone or mixed with 10 wt‐% and 50 wt‐% TiO2, SnO2, ZnO, and Al2O3 were pyrolyzed by using a pyrolysis gas chromatograph. Benzene, toluene, ethylbenzene, o‐xylene, styrene, naphthalene, and various chlorobenzenes were identified. No hydrocarbons could be detected in pyrolysis products of any samples at 200°C. More aromatic hydrocarbons than aliphatic hydrocarbons are released from the PVC–TiO2 system and in preheated PVC. The contrary result is observed in the PVC–ZnO and PVC–SnO2 systems. Aromatics having methyl endgroups are easily released from the PVC–ZnO and PVC–SnO2 systems and at elevated pyrolysis temperature, because methylene groups are easily isolated along the chain by ZnO, SnO2 and the heating. The release of ethylbenzene o‐xylene, and chlorobenzenes suggests a repeated dehydrochlorination and recombination of HCl and Cl2 to double bonds along the chain. Possible decomposition mechanisms of PVC are discussed.
Radical polymerizability of fumaramide derivatives
Authors: Azuma C. , Ogata N. 
Published: April 2003

AbstractVarious N‐cycloalkyl fumaramides having different characters of N‐cycloalkyl groups such as piperidine, morpholine, or pyrrolidone were synthesized and homopolymerized or copolymerized with styrene by use of a radical initiator and ultraviolet irradiation, respectively. N,N′‐Dipiperidinyl or ‐dimorpholyl fumaramides copolymerized with styrene to form a random copolymer, while N,N′‐fumaroyl dipyrrolidone tended to form an alternating copolymer with styrene, indicating that the electron distribution of the N‐cycloalkyl group affects the polymerizability of fumaramide derivatives. Photopolymerizability of these fumaramides was not as great as that of α,β‐unsaturated esters.
Binding of methyl orange and its homologs by polycations containing apolar pendant groups
Authors: Takagishi Toru , Nakata Yoshiro , Kuroki Nobuhiko 
Published: April 2003

AbstractThe binding of methyl orange, ethyl orange, and propyl orange by polycations involving various apolar pendant groups such as methyl, ethyl, benzyl, or dodecylbenzyl groups has been examined quantitatively by an equilibrium dialysis method at 5, 15, 25, and 35°C. The first binding constants and the thermodynamic parameters in the course of the binding have been calculated. The favorable free energy of the binding is accompanied by an entropy gain and an exothermic enthalpy change. The shorter the alkyl chain of the dyes or the polymers, the more negative is the enthalpy change and hence the smaller is the entropy change. Furthermore, an increase in binding affinity can be created in the polycation upon introduction of hydrophobic groups. In particular, the binding ability of the polycation containing a dodecylbenzyl group for methyl orange is almost 300‐fold that of bovine serum albumin. Therefore it is clear that hydrophobic interactions, as well as electrostatic ones, are involved in the binding.