bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of functional polyamides by the ritter reaction
Authors: Ogata Naoya , Saito Kenshi 
Published: April 2003

AbstractPolyamides having pendant functional groups such as hydroxyl, mercapto, or imine groups were synthesized by the Ritter reaction of dinitriles and trioxane in concentrated sulfuric acid. The polymerization of β‐hydroxyl glutaronitrile yielded a water‐soluble polyamide having a low molecular weight which might be ascribed to the participation of the hydroxyl group with the polymerization, while the polymerization of β‐mercaptoglutaronitrile resulted in the formation of a crosslinked polyamide which was insoluble in common solvents. Polymerization of dinitriles having imine groups yielded water‐soluble polyamides which were effective as a coagulation agent for colloidal solutions.
Graft polymerization of vinyl monomers onto cellulose in presence of soda lime glass. II
Authors: Mansour Olfat Y. , Moustafa Abd‐Allah B. 
Published: April 2003

AbstractIn the sodium bisulfite–soda lime glass initiating system, crude and true grafting yields increased with increasing ratio of methyl methacrylate to cellulose up to a limit; beyond this limiting value, grafting yields decreased due to the increase of the rate of sodium bisulfite‐monomer addition over that of polymerization. Limitation was also achieved on increasing the glass to cellulose ratio through increased termination rates by coupling and disproportionation reactions, as the free radicals are increased. In addition, a limiting value was reached with increasing sodium bisulfite concentration; this may be related to the formation of a nonfunctioning disulfite ion at the expense of bisulfite radicals at high concentrations of sodium bisulfite. The temperature plays a role in this initiating system. Maximum rates of conversion and grafting were achieved at the ceiling temperature. Dissociation of the sodium bisulfite, which decreases with temperature, also has an effect.
Aromatic polyethers, polysulfones, and polyketones as laminating resins. VI. Polymers from 2,5‐dicyanoterephthalic acid
Authors: Bruma Maria , Marvel C. S. 
Published: April 2003

AbstractAromatic poly(keto ether sulfones) containing various amounts of pendant cyano groups were synthesized from 1,4‐bis(p‐phenoxybenzoyl)‐2,5‐dicyanobenzene, 1,3‐bis(p‐phenoxybenzenesulfonyl)benzene, and isophthaloyl chloride by a Friedel‐Crafts type polymerization. These polymers softened at 160–190°C and had inherent viscosities of 0.44–0.61 in hexamethylphosphoric triamide. Crosslinkings were made by heating the polymers alone or in the presence of zinc chloride at 360–370°C to give black resinous materials that were insoluble in hexamethylphosphoric triamide in which the original polymers dissolved quite readily.
Determination of coisotacticities of some alternating styrene–acrylic copolymers by NMR spectra
Authors: Yokota Kenji , Hirabayashi Tadamichi 
Published: April 2003

AbstractCoisotacticities σ for some alternating copolymers were determined through the analyses of their CH3O, CH3 and CH2 proton NMR spectra; styrene–methyl methacrylate (σ = 0.56), styrene‐methyl acrylate (σ = 0.53), styrene–methyl α‐chloroacrylate (σ = 0.69), styrene–methacrylonitrile (σ = 0.19), styrene–methacrylamide (σ = 0.16), α‐methylstyrene–methyl methacrylate (σ = 0.21), and α‐methylstyrene–methyl acrylate (σ = 0.53) were studied. It was found that a terminal model or Bernoullian trial prevails in these complexed copolymerizations with diethylaluminum chloride. The influence of monomer structure on σ values is discussed.
Copolymerization of trioxane with cyclic acetals. Effect of catalyst on polymerization and monomer reactivity
Authors: Chen Catherine S. Hsia 
Published: April 2003

AbstractThe copolymerization of trioxane with cyclic acetals, viz., 1,3‐dioxolane, m‐dioxane, and 4‐methyl‐m‐dioxane, have been investigated. Three types of catalyst have been employed: a metal chelate, MoO2(AcAc)2; a Lewis acid, BF3·Bu2O; and an ion‐pair,
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It has been ascertained that, in agreement with the previous results on copolymerization of trioxane and ethylene oxide,1 both the polymerization kinetics and the monomer reactivity have been found to be influenced by the catalyst employed. In copolymerization with 1,3‐dioxolane, both BF3·Bu2O and
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have been found to give high molecular weight copolymers with high incorporation of 1,3‐dioxolane. However, contrary to the results obtained in copolymerization with ethylene oxide, higher rate and yield have been obtained with BF3·Bu2O, making it a superior catalyst. In copolymerization with m‐dioxane,
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has been found to be a superior catalyst to the others yielding high molecular weight copolymers with high incorporation of m‐dioxane. In copolymerization with 4‐methyl‐m‐dioxane, MoO2(AcAc)2 has been found to be an overall superior catalyst to the others. Higher rate, yield, and comonomer incorporation have been obtained using MoO2(AcAc)2 as catalyst, although somewhat higher molecular weight copolymers have been obtained with
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Poly(vinyl chloride‐g‐butyl rubber)
Authors: Kennedy J. P. , Davidson D. L. 
Published: April 2003

AbstractThe synthesis of poly(vinyl chloride‐g‐butyl rubber) and some of its physical properties are described. The key to the synthesis involves copolymerization initiation of an isobutylene–isoprene charge by a PVC/Et2AlCl initiator system with 1,2‐dichloroethane as solvent. The graft is a thermoplastic; cast films are flexible and optically clear. Proof of grafting is the crosslinking with S2Cl2 of the pentane‐extracted product in THF solution. Crosslinking the butyl rubber moiety in the graft reduces overall stress properties.
Polyimidothioethers
Authors: Crivello James V. 
Published: April 2003

AbstractThe condensation of maleimide compounds with hydrogen sulfide and bisthiols was studied in several model systems. Bismaleimide compounds undergo rapid, exothermic polymerization with thiol‐containing compounds in dipolar and basic solvents to give crosslinked polymidothioethers. Effective supression of the crosslinking reaction was achieved by carrying out the polymerization in the presence of a proton donor to inhibit anionic polymerization. A number of linear polyimidothioether homopolymers and copolymers were prepared and a study was made of their properties.
Polymerization of coordinated monomers. IX. Charge‐transfer spectrum of the system composed of metal halide, polar vinyl monomer, and electron‐donating monomer
Authors: Komiyama Makoto , Hirai Hidefumi 
Published: April 2003

AbstractThe 1:2 stannic chloride–methyl methacrylate complex, the 1:2 stannic chloride–acrylonitrile complex, the ethylaluminum dichloride–methyl methacrylate complex, and the ethylaluminum dichloride–acrylonitrile complex exhibit charge‐transfer absorption bands in the wavelength region longer than 300 nm with electron‐donating compounds such as mesitylene, styrene, toluene, and butadiene. The absorption spectrum of the mixture of either methyl methacrylate or acrylonitrile with the electron‐donating compound is, however, a superpostion of the spectra of the components without any additional absorption. Methyl isobutylate, 3‐butenyl methyl ketone, and propionitrile show no charge‐transfer absorption bands with the electron‐donating compound, even in the presence of a metal halide. Both the presence of the C‐C double bond conjugating with the polar group and the coordination of the polar group to a metal halide are essential for an electron‐accepting monomer to exhibit a charge‐transfer absorption with the electron‐donating compound. Continuous variation plots with the use of the charge‐transfer band definitely show a 1:1 interaction between the methyl methacrylate coordinated to stannic chloride and styrene, resulting in the determination of the equilibrium constants for the charge‐transfer complex formation in methylene chloride: 0.21 l./mole at 25°C and 0.67 l./mole at −50°C. The charge‐transfer absorption is attributed to a ternary molecular complex composed of a metal halide, a polar vinyl monomer, and an electron‐donating monomer.
Plasma polymerization of some organic compounds and properties of the polymers
Authors: Yasuda H. , Bumgarner M. O. , Marsh H. C. , Morosoff N. 
Published: April 2003

AbstractPlasma polymerizations (under 13.5‐MHz radiofrequency inductively coupled glow discharge) of some organic compounds are investigated by their properties (elemental analysis, surface energy, and infrared spectra) and their relations to the concentrations of free radicals in the polymers as detected by electron spin resonance (ESR) spectroscopy. Monomers that have been investigated are hexamethyldisiloxane, tetrafluoroethylene, acetylene, acetylene/N2, acetylene/H2O, acetylene/N2/H2O, allene, allene/N2, allene/H2O, allene/N2/H2O, ethylene, ethylene/N2, ethylene oxide, propylamine, allylamine, propionitrile, and acrylonitrile. Plasma‐polymerized polymers generally contain oxygen, even if the starting monomers do not contain oxygen. This oxygen incorporation is related to the free‐radical concentration in the polymer. Molecular nitrogen copolymerizes with other organic monomers such as acetylene, allene, and ethylene, and their properties are very similar to those of plasma‐polymerized polymers from nitrogen‐containing compounds such as amines and nitriles. The addition of water to the monomer mixture reduces in a dramatic manner the concentration of free radicals in the polymer and consequently the oxygen‐incorporation after the polymer is exposed to air. The concentrations of free radicals (by ESR) are directly correlated to the change of the properties of plasma‐polymerized polymers with time of exposure to the atmosphere. These changes are primarily the introduction of carbonyl (and possibly hydroxyl) groups. The addition of water to the plasma introduces these groups during the polymerization.
Polyimide structure–property relationships. I. Polymers from fluorene‐derived diamines
Authors: Bell Vernon L. 
Published: April 2003

AbstractA series of fluorene and fluorenone diamines were polymerized with two aromatic dianhydrides, and the resulting polyamic acids were cyclodehydrated to aromatic polyimides. A study of the mechanical properties of the polyimide films disclosed they are among the stiffest reported to date, with an excellent retention of rigidity at elevated temperatures. Comparisons of the tensile properties and glass transition temperatures of the fluorene‐derived polymer films with those from the corresponding open‐chain polyimide films established that the unusual rigidity, especially at elevated temperatures, was in large part due to the contribution of the bulky, tricyclic fluorene (one) moieties in the polymer structures.
1H‐NMR spectra of complexes between methacrylic monomer and ethylaluminium dichloride in toluene and methylene chloride
Authors: Furukawa Junji , Kobayashi Eiichi , Nagata Shiro 
Published: April 2003

Abstract1H‐NMR spectra of mixtures of a methacrylic monomer such as methacrylonitrile or methyl methacrylate and ethylaluminium dichloride at various molar ratios were measured in toluene or methylene chloride at various temperatures. It was found that only one kind of binary complex is detectable in the methacrylonitrile–ethylaluminum dichloride equimolar mixture, while in nonequimolar systems there are several kinds of binary complexes, depending on the molar ratio at low temperature in these solvents. Moreover, the chemical shifts of the protons of methacrylonitrile due to complex formation with ethylaluminum dichloride show a remarkable temperature dependence in toluene, but not in methylene chloride. This fact can be interpreted by an assumption of the formation of a ternary complex of methacrylonitrile, ethylaluminum dichloride, and aromatic donor molecules, mainly due to the dipole interaction between the nitrile group complexed with ethylaluminum dichloride and aromatic donor. The orientation of toluene molecules in the ternary complex of methacrylonitrile or methyl methacrylate is discussed.
Physical properties of some low polymer content radiation‐grafted wool copolymers
Authors: McLaren K. G. , Watt I. C. 
Published: April 2003

AbstractWool copolymers with low polymer content (6–18%) have been prepared by radiation grafting techniques. Supercontraction, density, and formic acid vapor sorption measurements have been used to assess changes in the keratin structure produced by the grafting processes. Kinetic studies of the contractile forces developed in the first (reversible) stage of the supercontraction of wool in lithium bromide showed that grafting with poly(N‐methylol acrylamide) or polyacrylonitrile has a “repairing” action which offsets changes in the wool structure produced by the small radiation dose (2 Mrad) used for the grafting process. By contrast, grafting with poly(vinyl acetate) had no repairing effect. The bonds formed by grafting of poly(N‐methylol acrylamide) or polyacrylonitrile to keratin do not reduce swelling of the wool by formic acid, which is a measure of effective crosslink density. Grafting with poly(vinyl acetate) led to increased swelling by formic acid, indicating some disruption of the keratin structure during polymerization. It is suggested that the role of the grafted polymer is mainly to stabilize the hydrogen‐bonded secondary network by interaction between the polypeptide and polymer chains.
Polymerization of coordinated monomers. X. Kinetic study of alternating copolymerization of methyl methacrylate and styrene with stannic chloride in dichloroethane
Authors: Komiyama Makoto , Hirai Hidefumi 
Published: April 2003

AbstractThe alternating copolymerization of methyl methacrylate with styrene with the use of stannic chloride was kinetically examined at −20°C in 1,2‐dichloroethane both under photoirradiation and with radical initiator (2:1 tri‐n‐butylboron‐benzoyl peroxide system). At conversions lower than 7%, the conversion increases linearly to the polymerization time, whereas the degree of polymerization is constant irrespective of the polymerization time. The alternating copolymerizations are 1.5 order and the 1.0 order reactions with respect to the ternary molecular complex composed of stannic chloride, methyl methacrylate, and styrene, under photoirradiation and with initiator, respectively. The linear dependences of the rates upon the 0.5 order of the intensity of the incident light and upon the 1.0 order of the concentration of tri‐n‐butylboron indicate a bimolecular termination. The rate normalized by the 1.5 order of the concentration of the coordinated methyl methacrylate and the rate normalized by the concentration of the coordinated methyl methacrylate are proportional to the 1.5 and 1.0 orders of the charged concentration of styrene, for the copolymerizations under photoirradiation and with initiator, respectively. The kinetic results in the 1,2‐dichloroethane solution are quite consistent with those in the toluene solution. The alternating copolymerization mechanism, in which the ternary molecular complex predominantly homopolymerizes as a monomer unit, is confirmed.
Interaction between dyes and polyelectrolytes. I. Effect of polyelectrolytes on the reaction of methylene blue with 1‐benzyl‐1,4‐dihydronicotinamide
Authors: Shirai Masamitsu , Tanaka Makoto 
Published: April 2003

AbstractThe effect of polyelectrolytes on the reaction of methylene blue with 1‐benzyl‐1,4‐dihydronicotinamide was investigated. An accelerating effect was observed on addition of sodium polystyrenesulfonate of poly(potassium p‐styrenesulfonate). On the other hand, deceleration was observed on addition of potassium polyvinylsulfate. No appreciable effect was observed when sodium p‐toluenesulfonate or potassium chloride was used as an electrolyte. An obvious color change was observed when methylene blue is bound to these anionic polyelectrolytes. Some correlations with spectral change of methylene blue and acceleration or deceleration effect are discussed.
Structure of chlorinated poly(vinyl chloride). III. Preparation of poly(vinyl chloride)‐β,β‐d2 as a model for the study of the mechanism of chlorination and of the chlorinated poly(vinyl chloride) structure
Authors: Lukáš R. , Kolínský M. 
Published: April 2003

AbstractA method for the preparation of poly(vinyl chloride)‐β,β‐d2 (PVC‐β,β‐d 2) as a model for the investigation of the mechanism of chlorination and of the CPVC structure has been suggested. The conditions of preparation of deuterated intermediates of a multistage synthesis of vinyl chloride‐β,β‐d2 and of suspension‐polymerized PVC‐β,β‐d2 have been described including the mass balance. Malonic acid was used as the starting compound. Tacticity values of a sample of PVC‐β,β‐d2 and its infrared and NMR spectra are presented and compared with data already published.
A new type of photodegradable polymer having a pyrazine moiety in the chain
Authors: Sakuragi Masako , Hasegawa Masaki , Nishigaki Masahiko 
Published: April 2003

AbstractPhotooxidative degradation of poly‐2,5‐distyrylpyrazine (poly‐DSP) has been studied in detail. Both amorphous poly‐DSP film and poly‐DSP solution were photooxygenated and degraded by irradiation by sunlight in the air. The nitrile group was formed, together with carbonyl groups and hydroxyl group. The photodegradation of a pyrazine derivative to a nitrile derivative is a new reaction. Next, photodegradation behavior of polymers having a cyclobutane moiety in the main chain, poly‐1,4‐bis[2‐(2‐pyridyl)‐vinyl]benzene (poly‐P2VB) and polydiethyl p‐phenylenediacrylate (poly‐p‐PDA Et), was studied. The photodegradability of these polymers decreases in the order: poly‐DSP > poly‐P2VB ≫ poly‐p‐PDA Et. Further, the photodegradation behavior of various vinyl polymers containing a vinylpyrazine or vinylpyridine component and polyamides having pyrazine or pyridine ring in the main chain, was investigated. Of these, polyvinylpyrazine has the largest photodegradability.
Eine quantitative, UV‐photometrische bestimmung von Endgruppen in polystyrolen
Authors: Kämmerer H. , Sextro G. , Seyed‐Mozaffari Ahmad 
Published: April 2003

AbstractStyrene was polymerized in bulk for 45 min at 70°C under a nitrogen atmosphere to a conversion of 6.16 weight‐percent with an aliphatic azo compound, which contained four p‐methoxyphenyl groups per molecule. The polystyrene could be purified easily by column chromatography and was then free of initiator and its decomposing products. It was separated into ten fractions by fractional precipitation (toluene/methanol), and the molecular weights of the polystyrenes were determined osmotically. The ultraviolet absorptions of the polystyrene solutions in dioxane were optically constant and followed the Bouguer‐Lambert‐Beer law. This made it possible to determine the number of absorbing groups per polystyrene molecule, which were constant with a value of 2. Polystyrenes with a number average molecular weight to 106 should be determinable in the same way.
Linear polythioesters. I. Products of interfacial polycondensation of 4,4′‐di(mercaptomethyl)benzophenone with terephthaloyl, isophthaloyl, and phthaloyl chlorides
Authors: Podkoscielny Wawrzyniec , Kultys Anna 
Published: April 2003

AbstractNew polythioesters have been obtained in the interfacial polycondensation of 4,4′‐di(mercaptomethyl)benzophenone with terephthaloyl, isophthaloyl and phthaloyl chlorides. The reactions were carried out at room temperature with the use of 10% excess of acid chloride per mole of mercaptan with vigorous stirring (2000 rpm). The organic phase was composed of benzene and hexane in equal volumes and the ratio of this mixture to water also was 1:1. The structure of the polythioesters was determined from elementary analysis and the infrared spectra. The molecular weight was not determined because of the very low solubility of polythioesters. Some thermal, mechanical, and electrical properties of the products have been determined. Products of dimercaptan with the terephthaloyl and isophthaloyl chlorides show the best properties.
Cationic polymerization of vinyl monomers initiated by phosphorus compounds containing halogens
Authors: Taninaka Takumi , Minoura Yuji 
Published: April 2003

AbstractPolymerization of vinyl monomers having large negative e values in the presence of phosphorus compounds containing halogens was studied in order to examine the cationic initiation ability of phosphorus compounds. N‐Vinylcarbazole was effectively polymerized by phosphorus compounds such as PCI3, PBr3, PCI2C6H5, PCI(C6H5)2, POCI3, and POCI2C6H5 even in benzene. The initiation ability of phosphorus compounds decreased in the order; PCI2 ≃ PBr3 > PCI2C6H5 > PCI(C6H5)2, and also POCI3 > POCI265. On the other hand, PCI3 and PBr3, which were less effective than POCI3, showed initiation ability for the polymerizations of styrene and α‐methylstyrene in nitrobenzene as a solvent. The results of the copolymerization of styrene with methyl methacrylate by PCI3 in nitrobenzene, the result of solvent dielectric constant effect, and the effect of additives such as water, tert‐butyl chloride, triethylamine, and hydroquinone, indicate the polymerization of styrene by PCI3 to proceed by a cationic mechanism.
Studies on the thickening reaction of polyester resins employed in sheet molding compounds
Authors: Gandhi K. S. , Burns R. 
Published: April 2003

AbstractThe mechanism of the thickening reaction between alkaline earth metal oxides and acid group‐terminated polyester resins was studied. The thickening can occur either by the increase in molecular weight of the resin through neutral salt formation or by complex formation between the basic salt and carbonyl oxygens. Simultaneous analysis of reacted resins for moisture content by near infrared spectroscopy and metal content by atomic spectroscopy was carried out to differentiate between the two possibilities. It was established that the amount of basic salt present in the reaction mixtures was small and hence the thickening appears to be due to neutral salt formation. The neutral salt formation reaction, being similar to condensation polymerization, could be modelled to predict the course of the thickening process as a function of time. A model proposed hypothesizes the thickening process to be heterogeneous in nature and to occur in a sequence of three steps: diffusion of metal oxide into the resin, reaction of the dissolved metal oxide with the resin to form the basic salt, and the further reaction of the basic salt with the resin to form the neutral salt. The model predicts all the observed features of the thickening process qualitatively. Further, quantitative agreement was obtained between experimental data and the theoretical predictions of plateau viscosities and in several aspects of the kinetics of the thickening process.
Spatially intermittent polymerization
Authors: O'Driscoll K. F. , Mahabadi H. K. 
Published: April 2003

AbstractA novel reactor has been designed which permits the precise determination of absolute rate constants in photoinitiated free‐radical vinyl polymerization. A solution of monomer and initiator flows through a dark tubular reactor past regularly spaced slots through which light shines. The alternating dark and light regions produce spatially intermittent polymerization (SIP) and make the system analogous to the well‐known rotating‐sector technique. However, the SIP reactor has the advantage of producing large volumes of reaction product, at low conversion, suitable for analysis of both conversion and molecular weight. This supplies the necessary data, from a single set of experiments, for the simultaneous determination of the rate constants for propagation and termination. Experimental data are reported at 25°C for methyl methacrylate which indicate that kp = 315 I./mole‐sec, independent of polymer molecular weight, and kt is dependent on molecular weight especially at low molecular weight, approaching a lower value of kt = 30 × 106 I./mole‐sec at a molecular weight of 106. For styrene, measurements being made only at high molecular weight, kp = 74 ± 5 and kt = 37 ± 0.3 × 106 l./mole‐sec at 25°C.