bluuebunny/crossref_metadata_2025_split huggingface dataset:
Plasma fluorination of polyolefins
Authors: Strobel Mark , Corn Stewart , Lyons Christopher S. , Korba Gary A. 
Published: April 2003

AbstractESCA and contact angle measurements were used to characterize the surfaces of Polyethylene and polypropylene films exposed to SF6, CF4, and C2F6 plasmas. None of these gases polymerized in the plasma. However, all plasma treatments grafted fluorinated functionalities directly to the polymer surfaces. SF6 plasmas graft fluorine atoms to a polyolefin surface. CF4 plasmas also react by a mechanism dominated by fluorine atoms, but with some contribution from CFx‐radical reactions. Although C2F6 does not polymerize, the mechanism of grafting is still dominated by the reactions of CFx radicals. For all gases studied, the lack of polymerization is attributed to competitive ablation and polymerization reactions occurring under conditions of ion bombardment.
Synthesis and polymerization of racemic and optically active β‐substituted β‐propiolactones. II: β‐monosubstituted and β‐disubstituted monomers and polymers with different optical purities
Authors: Lavallée Claude , Leborgne Alain , Spassky Nicolas , Prud'homme Robert E. 
Published: April 2003

Abstractβ‐(trichloromethyl)‐β‐propiolactone (CCl3‐PL), β‐(trifluoromethyl,methyl)‐β‐propiolactone (CF3, Me‐PL) and β‐(trifluoromethyl,ethyl)‐β‐propiolactone (CF3,Et‐PL) have been obtained by the reaction of ketene with chloral, 1,1,1‐trifluoroacetone and 1,1,1‐trifluorobutanone, respectively. Chiral catalysis lead to optically active monomers. The enantiomeric excess of the lactones has been measured by 1H‐NMR spectroscopy, in the presence of 2,2,2‐trifluoro‐1‐(9‐anthryl)ethanol or an europium chiral shift reagent. Polymerizations have been carried out in bulk or in toluene, at 60°C or 80°C, using mainly organometallic initiators. The Polymers become insoluble and crystalline at enantiomeric excesses over 80% for CCl3‐PL and 70% for CF3,Me‐PL. Melting temperatures were recorded from 238 to 268°C for poly(CCl3‐PL) and from 78 to 100°C for poly(CF3,Me‐PL), depending upon the molecular weight and the enantiomeric excess. The 13C‐NMR specroscopy of poly(CCL3‐PL) indicates that the polymerization of the corresponding lactone leads to polymers of increasing degrees of isotacticity with the enantiomeric excess of the monomer.
Thermal decomposition behavior of bis‐aminimides and their application to polymerization of epoxide
Authors: Inubushi Shinzo , Ikeda Tomiki , Tazuke Shigeo , Satoh Tasuku 
Published: April 2003

AbstractBis‐aminimide compounds [bis‐N, N,‐dimethyl‐N,‐(2‐hydroxypropyl)‐amine‐N,′‐adipimide (1) and bis‐trimethylamine adipimide (2)] were found to exhibit different thermal decomposition behavior and polymerization efficiency for an epoxide (phenyl glycidyl ether, PGE). The thermal decomposition rate of 1 was much higher than that of 2. It seemed that hydrogen bonding enhanced the decomposition rate. Compound 1 was thermolyzed to give a diisocyanate and a tertiary aminoalcohol, which subsequently reacted with each other to give a urethane. When 2 was heated, the isocyanate generated from 2 remained unreacted. PGE reacted with thoseaminimides to give different products, depending on their thermolyzed products. Mixtures of diisocyanate, tertiary amine, and PGE were used in the model reactions, and the thermal reaction between the expected decomposition products of aminimides was investigated in the presence and absence of PGE. The amount of high molecular weight fraction in PGE + 2 is greater than that of PGE + 1. In the former, the free isocyanate groups may act as a chain extender to give higher molecular weight fractions.
Polyelectrolyte containing dihydronicotinamide. II. Interaction of polymer and substrate
Authors: Itoh Yoshihiro , Wakisaka Kazuyoshi , Abe Koji , Senoh Saburo 
Published: April 2003

AbstractReduction of crystal violet (CV) by poly(sodium styrene‐p,‐sulfonate) containing dihydronicotinamide (NAH) groups (PNAH) was compared with that by poly(sodium 2‐acrylamido‐2‐methylpropanesulfonate) containing NAH groups (PNAH‐AMPS) in aqueous media. PNAH reduced CV far more effectively than PNAH‐AMPS, suggesting the presence of both hydrophobic and electrostatic interaction between PNAH and CV. An obvious color change was observed on addition of CV to the polyelectrolyte solutions, which was largely affected by the kind of polymers and the experimental conditions such as ionic strength and medium composition. These results imply that the location of CV within the macromolecular domain is an important factor for the polyelectrolyte‐induced metachromasy. Some correlations of the metachromatic behaviors of CV with the reduction were also discussed.
Phenyl thiazyl compounds: Synthesis and electrical conductivity
Authors: Ramakrishnan S. , Chien James C. W. 
Published: April 2003

AbstractA series of substituted phenylene‐dithio‐bis(phenyldithiazyl) (PDBPD) and phenylthiophenyldithiazyl (PTPD) compounds have been synthesized utilizing the facile reaction between N‐trimethyl silylimides and aromatic sulfenyl chlorides. The compounds are insulators with conductivities of 10−8–10−12 (Ω cm)−1. However, they can be oxidized with Br2 to conductivities of 10−3–10−5 (Ω cm)−1 for pressed pellets. Electron donating and withdrawing substituents on the phenyl ring markedly alter the electrical transport properties. While PTPD compounds are soluble in many solvents, the PDBPD derivatives are only sparingly soluble.
Isoprene polymerization with cerium(III) acetylacetonate–diethylaluminum chloride in toluene: Effects of water concentration
Authors: Lee Dong‐Ho , Jang Jae‐Kwon , Ahn Tae‐Oan 
Published: April 2003

AbstractIsoprene has been polymerized in toluene using a cerium(III) acetylacetonate–diethylaluminum chloride catalyst. The microstructure of obtained polyisoprene is predominantly trans‐1,4 structure. For this system the effects of water concentration on the conversion of isoprene to polymer, the microstructure and the molecular weight of polyisoprene have been examined. The conversion at a given polymerization time has a maximum at [H2O]/[DEAC] ratio of 1:0–1.1. The amounts of trans‐1,4 structure and the viscosity average molecular weights of polyisoprene are nearly independent of the water concentration. Although the conversion increases with the concentration of catalyst, the trans‐1,4 content is not affected by the catalyst concentration and the molecular weight of polyisoprene decreases slightly with increasing catalyst concentration.
Polyarylates (I): Investigation of the interfacial polycondensation reaction by UV
Authors: Tsai Hong‐Bing , Lee Yu‐Der 
Published: April 2003

AbstractThe interfacial polycondensation of bisphenol A with isophthaloyl chloride and terephthaloyl chloride in dichloromethane with triethylbenzylammonium chloride as the catalyst was described. A well‐defined two‐phase system had been observed, so the concentration of bisphenolate in the aqueous phase could be determined by UV spectrometer. The conversion was found to increase rapidly with reaction time, but the rate of increase in molecular weight was slow. At the initial stage with conversion up to 95%, the reaction proceeded similarly to that of solution polycon‐densation because the synthesized polyarylate could be dissolved in dichloromethane, and a polymer with a low molecular weight resulted. At the final stage of the reaction, the molecular weight was increased to a very high value due to the local concentration effect. The mole ratio of bisphenol A to diacid chlorides was found to affect the molecular weight very much. In the case of a mole ratio less than 1, the reaction remained in the initial stage mostly, and the molecular weight was low. However, for a mole ratio greater than 1, polyarylate with a very high molecular weight could be obtained because the local concentration effect was much more significant owing to the high concentration of bisphenolate that remained in the aqueous phase at the final stage.
Crosslinking reactions of 1,3,5‐tris(2‐methylaziridinyl‐1‐methyl)benzene (TRIMAM) with carboxyl terminated polybutadiene
Authors: Kishore K. , Dharumaraj G. Varghese , Rajalingam P. 
Published: April 2003

AbstractCuring reactions of a new crosslinking agent, 1,3,5‐tris(2‐methylaziridinyl‐1‐methyl)benzene (TRIMAM) with carboxylterminated polybutadiene have been studied by dynamic differential thermal analysis and by IR spectroscopy. The crosslinking reactions are found to be faster for this new compound compared with the conventional tris‐1‐(2‐methyl) axiridinyl phosphine oxide (MAPO).
Polymerization of acrylic acid initiated by a hexavalent chromium‐organic sulfur compounds reducing agent system
Authors: Lenka Subasini , Nayak Padma L. 
Published: April 2003

AbstractThe kinetics of polymerization of acrylic acid initiated by Cr6+‐thiourea, Cr6+‐thioacetamide, Cr6+‐2‐aminoethane thiol, Cr6+‐cysteine, and Cr6+‐thioglycollic acid have been studied at 30, 35, and 40°C in nitrogen. The rates of polymerization were measured. Chromic acid alone did not initiate the polymerization under deaerated and un‐deaerated conditions. On the basis of the experimental observation of the dependence of the rate of polymerization Rp on various variables, a suitable kinetic scheme is proposed.
Interaction of triphenylmethyl salts with vinyl ethers
Authors: Velichkova R. S. , Doicheva J. B. , Panayotov I. M. 
Published: April 2003

AbstractThe initiation of isobutyl, n‐butyl, ethyl, and 2‐chloroethyl vinyl ethers polymerization by trityl ion salts was investigated. The oligomers formed and the reaction mixtures were analyzed by GPC and 1H‐NMR spectroscopy. It is concluded that the initiation proceeds via two competing reactions. The addition of the initiator to the monomer is determined as usual by the electrophilicity of the former and the nucleophilicity of the latter. In order to realize initiation by hydride transfer it is necessary for the monomer to possess a hydrogen atom with hydride mobility and that the cation obtained is sufficiently stable. The relative part of these initiation reactions is determined.
Preparation and properties of silicon containing polyamides
Authors: Kiyotsukuri Tsuyoshi , Tsutsumi Naoto , Ayama Koichi , Nagata Minoru 
Published: April 2003

AbstractSilicon containing polyamides were prepared by melt polycondensation method with a 1,3‐bis(3‐aminopropyl)tetramethyldisiloxane and aliphatic dicarboxylic acids having various numbers of methylene groups. Only one endothermic peak appeared in the DTA curve of the quenched sample for polyamides having an even number of methylene groups in the repeating unit. Two endothermic peaks, however, appeared for the sample kept for a week in dry air at ambient temperature after quenching: the peak at the higher temperature is called peak I; and the peak at the lower one, peak II. By heat treatment at the higher temperature, peak II shifted to a higher temperature and increased its peak area, and peak I decreased its peak area while keeping its temperature unchanged. This behavior suggests the existence of two types of crystalline states. The peak temperature of peak I alternatively decreased with the increase of the number of methylene groups. The Young's modulus and the tensile strength increased with increase of annealing time at ambient temperature. The solubilities in various solvents, the resistance to alkali solution, and the thermal stability were acceptable. Both the permeation coefficient of oxygen (P) and the separation ratio (P/P) increased with the increase of silicon content in the repeating unit.
Photophysics of a sulfonated 2‐hydroxyphenylbenzotriazole UV absorber in solution and in polymer substrates
Authors: Ghiggino K. P. , Scully A. D. , Bigger S. W. , Leaver I. H. 
Published: April 2003

AbstractThe total absorption spectrum of the UV absorber sodium 2‐(2′‐hydroxy‐5′‐methylphenyl) benzotriazole sulfonate (TINS) has been resolved into contributions by two ground‐state forms in acetonitrile‐water solvent mixtures and hydrogen bonding polymer and protein substrates. These two ground‐state species can be assigned to (i) a planar intramolecularly hydrogen bonded form which can undergo the efficient nonradiative energy dissipation process of excited‐state intramolecular proton transfer (ESIPT), and (ii) a fluorescent nonplanar species in which ESIPT is effectively prevented. The mole fractions of each contributing conformer in the polymeric substrates have been estimated. In all the polymer systems studied, a significant proportion of the TINS molecules exist in the nonplanar form and thus may not contribute to photostabilization of the substrate. The proportion of nonplanar molecules varied from 11 to 86% in synthetic polymers and 20 to 41% in protein substrates.
Highly wettable films plasma‐polymerized from ethylene oxide
Authors: Inagaki N. , Suzuki K. 
Published: April 2003

AbstractHighly wettable films were prepared by plasma‐polymerization from ethylene oxide. The surface energy of the formed films is 65.6 dyn/cm, and the contact‐angle of water on the films is 12 degrees. The formation of highly wettable films is limited to the plasma‐polymerization conducted at low W/FM values of below 200 MJ/kg. Analyses by infrared spectroscopy and ESCA show that the formed films contain much oxygen residues such as CO, CO, and C(O)O groups. Such polar groups would contribute high wettability of the plasma‐films from ethylene oxide.
Free radical copolymerization of sulfur dioxide with phenylacetylene
Authors: Kim Seong‐Ju , Akiyama Fuminori , Matsuda Minoru 
Published: April 2003

AbstractFree radical copolymerization of sulfur dioxide with phenylacetylene (PA) in o‐dichlorobenzene was studied in a range of temperatures from 30 to 80oC as a function of total monomer concentration ([SO2] + [PA]). PA content in the copolymers increases with decreasing total monomer concentration and increasing temperature. Mw/Mn becomes sharper with decreasing the total monomer concentration, but does not depend upon feed compositions which are changed keeping total monomer concentration constant at 2, 4, and 6 mol/L, respectively. These results strongly indicate the existence of depropagation. Thermal decomposition of the copolymers happens more easily than PA homopolymer and the carbon‐centered free radicals are detected during the decomposition. Reactivity of ∼ CHĊ(Ph) free radical (∼ PA · ) is also discussed.
Conductivity of polydiacetylene with π‐conjugation between polymer backbone and substituents
Authors: Matsuda Hiro , Nakanishi Hachiro , Kato Shin‐Ichi , Kato Masao 
Published: April 2003

AbstractPoly‐1,4‐bis(3‐acetamidephenyl)‐1,3‐butadiyne, i.e., a topochemically obtained polydiacetylene for which one can expect π‐conjugation between polymer backbone and substituents, has been examined as a candidate of conducting polymers. Upon iodine doping, the polymer film attained the conductivity of 4.8 × 10−2 S/cm, i.e., about three orders of magnitude greater than those of other polydiacetylene films which have no such π‐conjugation.
Preparation of polysiloxanes from silicic acid. IX. Partially silylated silicic acid and its spinnability
Authors: Abe Yoshimoto , Kaijou Akira , Shintani Nobuhiro , Nagao Yukinori , Misono Takahisa 
Published: April 2003

AbstractThe reaction in different molar ratios of trimethylchlorosilane to silicic acid offered partially silylated silicic acids PSSX (X = OH) with various degrees of silylation. Esterification and acetylation of PSSX (X = OH) with 1‐butanol or acetylchloride gave polysiloxanes PSSX (X = OBun and OCOCH3). Some of them showed an excellent spinnability and provided a fine fiber with a length of about 250 cm. A fiber drawing test from concentrated PSSX solutions of various solvents revealed that spinnability markedly depended on the DS, functional group X of PSSX, and solvent. Spinnability may also be correlated to solubility parameter of PSSX and solvent.
Polymerization and copolymerization of an isocyanate blocking agent. N‐(1,1′‐dimethyl‐3‐oxobutyl) acrylamide oxime. Mechanical and thermal properties
Authors: Michaud P. , Camberlin Y. 
Published: April 2003

AbstractThe bulk polymerization and copolymerization of N‐(1,1′‐dimethyl‐3‐oxobutyl) acrylamide oxime have been studied. Polymerization of diacetone acrylamide oxime was carried out with different initiating systems. The rate of polymerization of diacetone acrylamide oxime with azoisobutyronitrile as the initiating system was much higher than with peroxides. However, in the case of perester initiating systems (t‐butyl perbenzoate and t‐butyl per ethyl‐2‐hexanoate), cobalt salt promoted the polymerization rate markedly. Diacetone acrylamide oxime readily formed copolymers with a variety of comonomers (crosslinking agents and reactive diluents). Gel permeation chromatography has shown a higher reactivity of diacetone acrylamide oxime with trimethylol propane trimethacrylate as crosslinking agent and N‐vinyl‐pyrrolidone as reactive diluent. Therefore, the dynamic mechanical analyses presented an increase in Tg with trimethylolpropane trimethacrylate and N‐vinyl‐pyrrolidone as comonomers. The terpolymer formed with diacetone acrylamide oxime, trinethylolpropane trimethacrylate, and N‐vinyl‐pyrrolidone exhibited interesting mechanical properties and high temperature behavior.
Synthesis of poly(alkylene phosphate)s with N‐containing bases in the side chains. II. 9‐N‐oxoethyleneadenine on the poly(trimethylene phosphate) chain
Authors: Łapienis Grzegorz , Penczek Stanisław , Aleksiuk Gennadij P. , Kropachev Viktor A. 
Published: April 2003

AbstractPoly(2‐hydro‐2‐oxo‐1,3,2‐dioxaphosphorinane) was quantitatively chlorinated, the resulting polymer was reacted with excess of imidazole giving the highly reactive polyesteramide. This polymer, treated with N‐hydroxyethyladenine with blocked amino group, gave polyphosphates with N‐oxoethyleneadenine in the side chains. The final polymers (Mn > 104) as well as the intermediate products were characterized by 1H‐, 13C‐, and 31P‐NMR spectroscopy. According to the spectra and analytical data the quantitative conversion: (A = adenine) was achieved.
Characterization of plasma polymers from tetramethylsilane, octamethylcyclotetrasiloxane, and methyltrimethoxysilane
Authors: Tajima Ichiro , Yamamoto Minoru 
Published: April 2003

AbstractThe products in inductively coupled plasma excited in organosilicic compounds were studied on chemical structures by spectroscopic methods. Plasma‐polymerized tetramethylsilane (PA) contains not only SiCH3 groups but also SiH groups on IR and 29Si‐NMR analyses. 13C‐NMR spectrum of PA reveals that the crosslinked structure of PA is mainly constructed of Ch2 and CH groups. Plasma‐polymerized octamethyleyclotetrasiloxane (PD4) is composed of SiCH3 and SiO groups. 13C‐ and 29Si‐NMR spectra of PD4 point out the highly preservation of the structural units similar to the monomer. These data of PD4 suggest that PD4 is formed from the ring‐opening polymerization by cleavages of SiO bonds. 13C‐NMR spectrum of poly[methyltrimethoxysilane] (PT) indicates the existence of CH3O groups, meanwhile its 29Si‐NMR analysis concludes that PT is chiefly composed of the structural units similar to the monomer. The surface analyses by XPS of PA, PD4 and PT suggest that these organosilicic plasma polymers resemble their starting materials.
Process parameters and their effect on grafting reactions in core/shell latexes
Authors: Merkel M. P. , Dimonie V. L. , El‐Aasser M. S. , Vanderhoff J. W. 
Published: April 2003

AbstractThe grafting of methyl methacrylate (MMA) onto polybutadiene (PB) latexes prepared by seeded emulsion polymerization at 50°C was investigated as a function of: (a) initiator concentration used in the secondary polymerization, (b) monomer‐to‐polymer ratio, (c) the specific surface area of the seed latex, and (d) the degree of conversion. The thin layer chromatography/flame ionization detection (TLC/FID) technique was used to determine the proportion of graft copolymer in the core/shell latex, It was found that grafting PMMA onto PB depended upon the concentration of initiator, decreasing as the concentration was increased. The amount of grafting increased with increasing specific surface area of the seed latex, while the molecular weight of the acetone‐soluble graft copolymer decreased. The amount of graft copolymer was found to decrease concurrently with increasing monomer‐to‐polymer ratio and degree of conversion. These results suggest a hydrogen abstraction mechanism in the formation of graft PB–PMMA through a chain transfer process.
Polymerization of N‐vinylcarbazole by transition metal salts
Authors: Cho Hyun‐Nam , Choi Sam‐Kwon 
Published: April 2003

AbstractThe polymerization of N‐vinylcarbazole (NVC) in the presence of transition metal salts such as WCI6, MoCI5, TaCl5 and NbCl5 under different reaction conditions was studied. In general, aromatic solvents were found to be superior to aliphatic solvents in the polymerization of NVC, i. e., both conversion and molecular weight were higher in aromatic solvents. It was observed that the polymerization reaction proceeds rapidly and almost quantitatively, even at low monomer concentration (< 5 × 10−2M) and at low catalyst to monomer mole ratio (10−5) in aromatic solvents. The copolymerization of NVC with acenaphthylene (ACN) was also investigated in solution at room temperature. The resulting homo‐ and copolymer were characterized by IR, NMR, x‐ray diffraction, and elemental analysis. Thermal and photophysical properties are also reported. From the spectral data, the polymerization solvent was found to have a strong influence upon the polymer stereoregularity.
Synthesis and properties of polyurethanes and polyureas containing 2,5‐thiophenylene linkage
Authors: Kwon Soon‐Ki , Choi Kil‐Yeong , Choi Sam‐Kwon 
Published: April 2003

AbstractA novel diisocyanate monomer, thiophene‐2,5‐diisocyanate (ThDI) was prepared from readily available adipic acid via the intermediate formation of thiophene‐2,5‐dicarboxylic acid chloride (ThDAC) and thiophene‐2,5‐dicarboxylic acid azide (ThDAA) which was subjected to a Curtius rearrangement. Polyurethanes and polyureas containing 2,5‐thiophenylene linkage were synthesized by the polycondensation of thiophene‐2,5‐diisocyanate with various diols and diamines, respectively, in N,N‐dimethylformamide. Polymerization conditions were optimized and the high yields of polymers were obtained. The identity of ThDI, model compounds, and the resulting polymers was confirmed by elemental analysis and spectroscopic methods. These polyurethanes and polyureas were found to have inherent viscosities in the range of 0.33–0.68 dL/g. Some physical properties of these polymers were also investigated.
Novel polyamides with acyclic and cyclic bipyridinediyl diamino structures in the polymer backbone: Synthesis and complexation with transition metals
Authors: Pappalardo S. , Bottino F. , Finocchiaro P. , Mamo A. 
Published: April 2003

AbstractThe synthesis of two novel polyamide ligands 3 and 4, containing 2,17‐diaza[3.3](6,6′)‐2,2′‐bipyridinophane or 6,6′‐bis(2‐picolylaminomethyl)‐2,2′‐bipyridine units as part of the polymer backbone, respectively, and of the appropriate diamide model compounds 1c and 2c is described. 1H‐NMR and IR spectral data support the ligand structures; furthermore, 1H‐VTNMR analysis on macrocyclic diamide 1c indicates a restricted rotation of the amide bonds at ambient temperature and suggests for this molecule a fixed syn conformation in solution, with a “face to face” arrangement of the dipyridinyl moieties. Model compound 2c and polyamide 4 form stable 1:1 complexes with transition metals Co(II), Ni(II), and Cu(II). Conversely, macrocyclic model 1c and polyamide 3 exhibit the unique property to specifically complex Cu(II), even in the presence of sizeable amounts of Co(II) and Ni(II). The IR spectral changes related to the ligands upon complexation are briefly discussed.