bluuebunny/crossref_metadata_2025_split huggingface dataset:
The structure of the highly conjugated polymers of dichloroprotoanemonin
Authors: Winston Anthony , Chapman David A. 
Published: June 2010

AbstractThe copolymerization of dichloroprotoanemonin with methyl methacrylate is accompanied by the elimination of half of the chlorine that originally entered the copolymer. This result is consistent with a 1,4‐addition mechanism, the product of which would readily eliminate hydrogen chloride. A strong infrared band at 1770 cm.−1 and a weak band at 1810 cm.−1 indicates that the loss of hydrogen chloride proceeds primarily by 1,4‐elimination but to a small extent by 1,2‐elimination. The copolymerization of dichloroprotoanemonin with styrene results in the elimination of 10 to 20% of the total chlorine that entered the copolymer. Infrared bands at 1765 and 1800 cm.−1 reveal the presence of both conjugated and nonconjugated lactone carbonyl groups. Treatment of the copolymer with hot pyridine resulted in further elimination, up to about 30% of the total chlorine. The decrease in the intensity of the 1800 cm.−1 band relative to the 1765 cm.−1 band as a result of the pyridine treatment confirmed the conversion of the nonconjugated structure into the conjugated one. The failure to achieve 50% elimination indicates that in the styrene case copolymerization may have occurred in part by 1,2‐addition, the product of which would not be expected to lose hydrogen chloride. These results suggest that the ratio of 1,4‐ to 1,2‐addition may depend in part upon the nature of the comonomer. Thermal homopolymerization of dichloroprotoanemonin at 210°C. results in a solid, black polymer, insoluble in the common solvents. The elimination of 76% of the total chlorine suggests that under the conditions of the polymerization the lactone ring opens, giving an α‐chloroketone, which then undergoes further elimination.
Polymerization of methyl methacrylate initiated by a photosensitive complex of tetrahydrofuran‐maleic anhydride in paraffin mixture
Authors: Berger J. , Lazár M. 
Published: June 2010

AbstractWe investigated the polymerization of methyl methacrylate, initiated by decay products of the complex formed by maleic anhydride and tetrahydrofuran and by the action of visible light. The polymerizations were effected in solid and melted paraffin at temperatures of 6 to 60°C., mostly with an 80% paraffin content. The solid‐paraffin mixtures showed high polymerization rates, a higher efficiency of photoinitiated polymerization, and an entire lack of thermal polymerization.
Polymérisation de la 4‐Vinylpiridine sur les “Matrices” Polyacides
Authors: Kargina O. V. , Kabanov V. A. , Kargin V. A. 
Published: June 2010

AbstractLa polymérisation de la 4‐vinylpyridine (VP) dans des solutions aqueuses d'un acide polymérique faible – l'acide polyacrylique (PAA) – a été étudiée. On a démontré que lors de l'interaction de la VP avec le PAA une polymérisation spontanée de la VP a lieu. Suite à une extraction on a réussi à séparer la poly‐4‐vinylpyridine obtenue sur PAA. La polymérisation de la VP sur le PAA se produit avec une grande vitesse (le temps de demi‐transformation est de 17 min.). La vitesse de polymérisation Vp de la VP dans les solutions d'acide acétique, qu'on peut considérer comme un modèle de bas poids moléculaire du PAA, est très petite. La Vp de la VP montre une grande dépendance de la grandeur de pH du milieu, pareille au cas de la polymérisation de la VP sur les acides polymériques forts, ce qui peut témoigner de la similitude des mécanismes de ces processus. La polymérisation de la VP dans les solutions aqueuses est accompagnée d'un accroissement du pH du milieu. Empiriquement, il a été établi que la relation entre le degré de conversion et la concentration des ions [H3O+] est donnée par l'expression suivante:

où [H3O+]0 est la concentration des ions [H3O+] au moment initial. On a étudié la polymérisation de la VP sur le PAA partiellement titré par une base non‐polymérisable. On en déduit une conclusion sur le mécanisme de polymérisation de la VP sur le PAA.
Oligoestermaleinates containing isocyanuric rings
Authors: Alaminov H. , Michailov M. , Damianova I. 
Published: June 2010

AbstractA method of preparing oligoestermaleinates containing isocyanuric rings by copolycondensation of 3‐(N‐2‐hydroxy‐3‐chloropropyl)isocyanurate, compound (II), and of 3‐(N‐2‐hydroxy‐3‐phenoxypropyl)isocyanurate, compound (III), with maleic anhydride alone or in mixtures with aliphatic or aromatic monocarbonic and dicarbonic acids has been developed. The copolycondensations were made with maleic anhydride, with maleic and phthalic anhydride, with maleic anhydride and adipinic acid, with maleic anhydride and oleic acid, and with maleic anhydride and stearic acid and were examined systematically. Oligoestermaleinates obtained from compound (III) have a higher temperature of dropping(dropping point) and a considerably higher thermostability than those obtained from compound (II). The oligoestermaleinates obtained from compound (II) with maleic anhydride and stearic or oleic acids are soluble in styrene and aromatic hydrocarbons; those obtained with the other substances are partially soluble in styrene. All those obtained from compound (III) are soluble in styrene. The isocyanuric oligoestermaleinates synthesized are compatible with the commercial oligoestermaleinates, such as those from ethylene glycol, diethylene glycol, and propylene glycol, and with their styrene solutions. The hardened isocyanuric oligoestermaleinates have a considerably greater thermostability than commercial oligomers hardened under the same conditions on an ethylene glycol, diethylene glycol, propylene glycol, or maleic anhydride base. The crosslinked polymers are flame‐resistant.
Obtention de membranes semi‐perméables à propriétés remarquables par le greffage radiochimique de films de polytetrafluoroéthylène
Authors: Bex G. , Chapiro A. , Huglin M. B. , Jendrychowska‐Bonamour A. M. , O'Neill T. 
Published: June 2010

AbstractSemipermeable membranes were prepared by grafting in the bulk Teflon films with acrylic acid, 4‐vinyl pyridine, and both monomers together by a method of successive grafting. Some kinetic features of these reactions are described. The swelling of the grafted membranes was investigated. In the case of vinylpyridine grafts the swelling properties were also examined after quaternization of the pyridine groups by HCl. A wide variety of membranes can be prepared by the methods described. These membranes exhibit excellent mechanical properties, even in the swollen state, and withstand remarkably well various corrosive media.
Thermodestruction and thermooxidative destruction of polyurethanes
Authors: Tarakanov O. G. , Orlov V. A. , Beljakov V. K. 
Published: June 2010

AbstractIt has been shown that the mechanism of destruction of the urethane group is determined by the structure of the starting components. The electron‐donating properties of the radical attached to the isocyanate group favor dissociation of the urethane group into isocyanate and alcohol, and electron‐accepting ones favor splitting of the urethane group into CO2 and amines. The effect of the alcohol radical is quite contrary to the effect of the isocyanate radical: the electron‐donating properties of the radical favor splitting into CO2 and amines, and the electron‐accepting ones favor dissociation of the urethane group into isocyanate and alcohol. The study of the effect of the foam‐forming catalysts on polyurethane destruction has shown that triethylenediamine and stannous dioctoate slightly accelerate the destruction processes. Being the catalyzer of the hydrolytic splitting, tin diethyl dicaprilate greatly accelerates the destruction in the presence of moisture only. It has been shown that urethane and urea groups of toluene diisocyanate polyurethanes improve the polymer stability toward thermooxidative destruction. In the course of the thermooxidative destruction of polyurethanes based on poly(oxypropylene) glycol the chain‐radical process of oxidation of the polyether unit of a macromolecule occurs.
Thermodynamic equilibrium in the system macromolecular coil–binary solvent
Authors: Pouchlý Julius , živný Antonín , Šolc Karel 
Published: June 2010

AbstractThermodynamic conditions of an equilibrium between a swollen coil and a solvent outside the coil, established in a dilute solution of a polymer in a binary solvent, are expressed in terms of quantities related to the unit volume. The impossibility to correlate unambiguously preferential sorption with the concentration change of overall sorption is discussed by means of an analogy of Gibbs adsorption equation. Equations expressing the preferential sorption of one of the components in the coil and the overall swelling of the coil in terms of partial derivatives of the free enthalpy of mixing with respect to composition are derived. These equations facilitate the calculation of preferential and overall sorption from theoretical or semiempirical relations expressing the composition dependence of ΔGM, the free enthalpy of mixing. The application is shown on a treatment of data obtained by the measurement of dialysis equilibrium and intrinsic viscosity in the system polymethylmethacrylate–benzene–methanol. The possibility of generalization of the equations derived to the case of osmotic and vapor‐pressure equilibrium in dilute solutions of a polymer in a binary solvent is pointed out. The relation of the equations for osmotic equilibrium to the Scatchard equations is discussed as well.
An estimation of the polydispersity of fractions by means of the mathematical fractionation method
Authors: Bohdanecký Miloslav 
Published: June 2010

AbstractThe method of mathematical fractionation was used to estimate the values of the polydispersity index (u = Mw/Mn) of the fractions obtained from a polymer with the Schulz‐Zimm distribution of molecular weights. A general correlation of u values with the fraction size and phase volume ratio was established. A minimum was found in the dependence of the polydispersity index on the fraction size (at about 30–40%). On the basis of these calculations conditions could have been predicted for fractions with u = 1.1 to be obtained in a larger amount (20–30% by weight of the original polymer).
The effect of excluded volume on chain dimensions
Authors: Alexandrowicz Z. 
Published: June 2010

AbstractExcluded volume‐interactions are treated in terms of the Gaussian probabilities for intersegmental contacts, as obtaining in equivalent chains consisting of links expanded by the interactions but otherwise obeying the random‐flight statistics. The linear development of the interaction energy exponent into the contact probabilities is (a) conducted sequentially segment by segment, so that the “chain connectivity” is duly preserved (difference from Flory), and (b) cast into a formula that uses Gaussian expressions only for the contact probabilities; the use of the Gaussian expression for the distribution of the end‐to‐end distance, which is known to be non‐Gaussian, is, however, avoided (difference from Fixman). An integral equation is derived, describing α(z) by a line which initially, up to α2 < 4, closely resembles the line derived by Fixman but thereafter diverges increasingly, the asymptotic result being α ≈︁ z5½−2 = z0.236….
Grafting acrylic acid to starch by preirradiation
Authors: Reyes Zoila , Syz Martin G. , Huggins Maurice L. , Russell C. R. 
Published: June 2010

AbstractThe grafting of acrylic acid (AAc) to starch was investigated with gamma‐pre‐irradiated starch and aqueous solutions of AAc. The rate of grafting increased initially with time, then decreased, and approached zero when the percentage grafting reached a maximum value. At a given radiation dose the rate of grafting was proportional to the first power of the concentration of irradiated starch and to the 1.5 power of the initial concentration of AAc. Solvent effects on degree of grafting, molecular weight, and number of grafted branches were evaluated. Higher degrees of grafting were achieved with electron‐irradiated starch at radiation doses lower than those used with gamma rays.
A new technique for polymer grafting
Authors: Bamford C. H. , Duncan F. J. , Reynolds R. J. W. , Seddon J. D. 
Published: June 2010

AbstractInitiation of free‐radical polymerization by metal carbonyl–organic halide systems has been extended to the case in which the halide component is a N‐halogenated amide or alkylamide. Evidence is presented to show that the nitrogen atom becomes attached as a terminal group to the polymer chain. The halogenated amide group may form an integral part of a polymer. Thus, N‐halogenated polymers may be used with metal carbonyls as initiating systems, so that this technique provides a new means of grafting vinyl polymers on to preformed chains containing CONH groups. Data presented for the grafting of a number of vinyl monomers on to polyamides, polypeptides, and natural proteins enable a detailed mechanism of grafting to be deduced.
Thermally stable amide–bithiazole ordered copolymers
Authors: Preston J. , Black W. B. 
Published: June 2010

AbstractSeveral thermostable ordered amide–bithiazole copolymers were prepared by low‐temperature solution polycondensation of aromatic diacid chlorides with bis(aminophenyl)bithiazoles. Films were readily prepared from all of these polymers, and a fiber was prepared from one of them. The polymer from isophthaloyl chloride and 4,4′‐bis(4‐aminophenyl)‐2,2′‐bithiazole was studied in the most detail. Unlike arylene–bithiazole polymers, which are soluble only in concentrated sulfuric acid and the like, this polymer is readily soluble in dimethylacetamide containing 5% dissolved lithium chloride, giving solutions suitable for film and fiber formation. The facile solubility of this amide–bithiazole polymer is attributed to the presence of the amide bonds. Crystalline fibers were spun from the dimethylacetamide–lithium chloride solution of this polymer; they had a tenacity of 140,000 psi (7.8 g./den.) at room temperature and a tenacity of 38,000 psi (2.1 g./den.) when measured at 450°C. The fiber undergoes a weight loss of only 10% on heating up to 490°C. in nitrogen at a rate of 15° C./min. All of the ordered amide–bithiazole copolymers developed a pink‐brown color upon exposure to light.
Study of wall effect in flow of polymer solution in capillary
Authors: Mineshita Takeshi , Watanabe Takehiko , Ono Sǒzaburo 
Published: June 2010

AbstractThe flow behavior of a solution of poly(vinyl pyrrolidone) (Mv, 1.0 × 104−9.0 × 105) has been studied at 35°C. in pure water, in 0.25M MgCl2 aqueous solution, in n‐propanol, and in water‐n‐propanol at various concentrations (0.5‐1.5 g. per 100 ml.). The measurements were carried out with a Maron‐Belner low‐shear capillary viscometer with various capillary bore sizes (radius R, 0.0190–0.0761 cm.) within the range of shear stress, 0.2–20 dynes/cm.2 at the capillary wall. The viscosity is 10–30% lower in the smallest capillary bore than in the largest one at the same shear stress. This phenomenon may be attributed to a steric hindrance of the capillary wall to the thermal motion of the polymer molecules near the wall. The results are represented by the modified Ree‐Eyring generalized flow formula, for a flow system containing one Newtonian flow unit and one non‐Newtonian unit, which includes the new additional terms dependent on the capillary bore size. Furthermore, by assuming the existence of wall layer (of thickness d) in the liquid flowing in the capillary tube an equation of the viscosity was derived, and by combining this equation with the aforementioned equation a calculation of the thickness d, where the rate of shear tends to infinity, was attempted.
Elastomers based on cellulose fibers
Authors: Nakamura Yoshio , Negishi Michiharu , Kakinuma Toshiko 
Published: June 2010

AbstractTo synthesize a new type of elastomer based on cellulose fiber, the introduction of intermolecular crosslinkage with formaldehyde, decrystallization or disorder with ZnCl2 swelling, and grafting with acrylate having a homopolymer second‐order transition temperature below room temperature were tried on the viscose rayon fiber. First, graft copolymerization with MA, EA, and BA was carried out in an aqueous emulsion system by the ceric ion method. It was found that the breaking elongation and elastic recovery of EA‐grafted fibers were remarkably superior to those of fibers grafted with the other monomers. Grafting with EA was carried out on formalized fibers with and without preswelling by concentrated ZnCl2 solution. The grafted fibers after formalization revealed typical rubber elastic behavior over several hundred per cent graft‐on. Breaking elongation was much increased by the swelling treatment after formalization. The crystallinity of the cellulose parts in the grafted fibers was decreased by the swelling pretreatment, being hardly changed by increasing the extent of grafting. The degree of orientation of the cellulose parts was decreased by increasing the extent of grafting, especially in the case of swelling before grafting. From these results it was concluded that the flexible graft parts correspond to soft segments and the rigid cellulose parts reinforced by crosslinkage correspond to hard segments, and that in this way elastomeric behaviors is developed.
Solid‐state polymerization in glassy state at low temperature
Authors: Tabata Yoneho , Ishigure Kenkichi , Fujita Yoshio , Oshima Keichi 
Published: June 2010

AbstractThe polymerization of various monomers in the glassy state was investigated at low temperatures and compared with polymerization in the crystalline state. It was found that acrylonitrile can polymerize in the glassy state in 2‐methyltetrahydrofuran via an anionic mechanism, and the rate of polymerization is much faster in the glassy state than in the crystalline. On the other hand, it was observed that acrylonitrile can be copolymerized with vinyl acetate in glassy mixtures of the two monomers over a wide range of monomer concentrations at low temperatures, below about −160°C. From the monomer reactivity ratio of two monomers in the two component system the polymerization is believed to proceed via a radical mechanism. It was also found that propylene oxide can polymerize only in the glassy state, and the rate of polymerization is quite rapid in matrices of methylene chloride. It was suggested from the effect of various additives on the polymerization that the polymerization proceeds via a cationic mechanism.
Synthesis of poly(ethylene 1,2‐diphenoxyethane‐p,p′‐dicarboxylate) and its properties as a fiber
Authors: Morita Minoru , Yamada Tsuyoshi , Kubo Teruo , Mihara Shigeru , Okajima Saburo 
Published: June 2010

AbstractThe synthesis of poly(ethylene 1,2‐diphenoxyethane‐p,p′‐dicarboxylate) and its properties as a fiber is reported. The polycondensation and properties of polyester (polyethylene terephthalate) and polyetherester (PEBC; half the ester linkage of the original polyester was replaced by ether linkage) were compared. It was concluded that (1) polycondensation reaction of both polyester and polyetherester proceeds under the same conditions, and polyetherester is not easily stained on account of its good thermal stability, (2) almost the same values were obtained for heat of fusion and fusion entropy of each polymer, (3) polyetherester is highly superior to polyester in stability to hydrolysis, (4) there is not much difference between the two fibers in crystallinity, (5) low elongation and high Young's modulus filament was obtained from polyether at high draw ratios, and (6) polyetherester is highly superior to polyester in dyeing affinity. These characteristics of polyetherester were considered to be based on the fact that half the ester linkage of polyethylene terephthalate was replaced by ether linkage.
The diethylzinc–L‐α‐amino acid systems as catalysts for the asymmetric‐selection polymerization of propylene oxide
Authors: Furukawa Junji , Kumata Yoshiyuki , Yamada Koji , Fueno Takayuki 
Published: June 2010

AbstractThe binary systems consisting of equimolar amounts of diethylzinc and L‐α‐amino acids were found to be effective as catalysts for the asymmetric‐selection polymerization of propylene oxides. Various L‐α‐amino acids were compared, in order to investigate the influence of the spatial character of the asymmetric center of catalysts on their efficiencies for asymmetric selection. It was found that all the L‐α‐amino acids investigated allow ( – )‐propylene oxide to polymerize preferentially over the (+) enantiomer, irrespective of the sign of their specific rotations, [α]D. For each amino acid the [α]D value of recovered monomer was proportional to –1n (1 – x), where x is the extent of polymerization. The proportionality factor, which may be regarded as a measure of the relative asymmetric‐selection efficiencies of catalysts, was found to parallel the bulkiness of the alkyl group attached to the asymmetric carbon atom of the amino acids used.
Stereoregular polymerization of optically active monomers with optically active and inactive catalysts
Authors: Matsuzaki Kei , Tateno Noriaki 
Published: June 2010

AbstractMixtures of l‐ and dl‐menthyl methacrylates were polymerized with phenylmagnesium bromide coordinated with l‐menthyl ethyl ether, and l‐ and dl‐amylmagnesium bromide as catalysts. The isotacticity of the polymers was decreased by the addition of dl‐monomer into l‐monomer. From the relationship between the decrease of isotacticity and the increase of heterotacticity and syndiotacticity it is deduced that the isotactic sequences in the polymers are composed of either D or L configurations and not mixtures of D and L sequences. The optical activity of the monomer recovered and that of the polymers showed that the preference of one of the enantiomeric monomers over the other in the polymerization did not occur. The polymers prepared with l‐ and dl‐amylmagnesium bromide had the same stereoregularity.
Studies on the charge‐transfer complex and polymerization. XI. Donor‐acceptor interaction in alternating radical copolymerization
Authors: Yamashita Yuya , Iwatsuki Shouji , Kokubo Takashi 
Published: June 2010

AbstractThe microstructure of the copolymer of butadiene with maleic anhydride has been shown by IR spectra to be rich in cis‐1,4 structure (about 70% at 60°C.), whereas the butadiene homopolymer by radical mechanism is rich in trans‐1,4 structure. The copolymer rich in cis‐1,4 structure was also observed in the copolymerization of butadiene with sulfur dioxide, but the copolymers of butadiene with styrene, acrylonitrile, dimethyl maleate, diethyl fumarate, or fumaronitrile were rich in trans‐1,4 structure. Because the free butadiene monomer exists as the transoid structure, the activation of butadiene through the cisoid complex is assumed in the copolymerization with maleic anhydride. This shows that the donor‐acceptor interaction between butadiene and maleic anhydride or sulfur dioxide participates in this alternating radical copolymerization, and the small alternating tendency observed between butadiene and acrylonitrile, maleate, or fumarate comes from the stabilization of the transition state by electrostatic interaction or electron transfer.