bluuebunny/crossref_metadata_2025_split huggingface dataset:
New poly(amide‐lmide)s syntheses. XV. Preparation and properties of poly(amide‐imide)s derived from 9, 9‐bis[4‐(4‐aminophenoxy) phenyl]fluorene and various bis(trimellitimide)s
Authors: Yang Chin‐Ping , Lin Jiun‐Hung 
Published: April 2003

AbstractFifteen bis(phenoxy) fluorene‐containing poly(amide‐imide)s III were synthesized by the direct polycondensation of 9,9‐bis[4‐(4‐aminophenoxy)phenyl]fluorene (BAPPF) with var‐ious aromatic bis(trimellitimide)s II in N‐methyl‐2‐pyrrolidone (NMP) using triphenyl phosphite and pyridine as condensing agents. Poly(amide‐imide)s III having inherent vis‐cosities up to 1.45 dL/g were obtained in quantitative yields. Most of the resulting polymers showed an amorphous nature and were readily soluble in polar solvents such as NMP and N,N‐dimethylacetamide. All the soluble poly(amide‐imide)s afforded transparent, flexible, and tough films. The glass transition temperatures of these polymers were in the range of 263–315°C and the 10% weight loss temperatures were above 510°C in nitrogen. Some properties of poly(amide‐imide)s III were compared with those of the corresponding isomeric poly(amide‐imide)s III′ prepared from 9,9‐[4‐(4‐trimellitimidophenoxy)phenyl]fluorene and various aromatic diamines. © 1995 John Wiley & Sons, Inc.
Spectral and thermal characterization of polyaniline–oxalic acid salt
Authors: Palaniappan S. 
Published: April 2003

AbstractPolyaniline–oxalic acid salts were prepared at 5 and 30°C by chemical polymerization of aniline using different concentration of oxalic acid. Polyaniline base was obtained from the corresponding polyaniline salt by dedoping using aqueous ammonium hydroxide solution. Conductivity measurements, elemental analysis, Infrared, electronic absorption, electron paramagnetic resonance spectral, and thermogravimetric analysis were performed on the polyaniline salts and bases. Composition and the extent of dopant in polyaniline salt systems where determined. The value of composition of polyaniline: oxalic acid is 4: 1.6 and the polymer yield is around 66%. The value of conductivity, polymer yield and composition of polyaniline–oxalic acid salt is independent of concentration of oxalic acid used and also the synthesis temperature. The results are compared with polyaniline–hydrochloride salt prepared by chemical polymerization. The conductivity of polyaniline–oxalic acid salt is three orders of magnitude lower than that of polyaniline‐hydrocholoride salt. © 1995 John Wiley & Sons, Inc.
Solution viscosity behavior of polystyrene‐based cationic ionomers: Effects of quaternary‐group structure and counter ion
Authors: Ohtani Noritaka , Inoue Yukihiko , Kaneko Yasumasa , Okumura Shinsuke 
Published: April 2003

AbstractThe dilute solution viscosity was investigated for several polystyrene‐based cationic io‐nomers. It was found that intramolecular aggregation among the ionic groups was strongly dependent on the sizes of quaternary onium groups and counter anions. The extent of the aggregation was controled by the solvent polarity and the solvation to the ionic groups. When there was a strong selective soivation to small counter ions, the structure of onium groups shows a minor effect on the viscosity behavior, indicating little aggregation among the ionic groups. A strong solvation to small quaternary cations also eliminates the intra‐molecular aggregation and the influence of counter ions was barely observable. When the selective solvation to counter ions was disabled by the enlarged size of the counter ions, however, the viscosity depended on onium group structure or spacer chain length. If the solvent solvates neither counter ions nor quaternary groups, the smaller the sizes of onium cation and counter anion, the lower the reduced viscosity due to an enhancement of the ionic aggregate formation. © 1995 John Wiley & Sons, Inc.
Polymerization and characterization of polyfunctional amphiphilic diacetylenes
Authors: Nezu S. , Lando J. B. 
Published: April 2003

AbstractAmphiphilic diacetylenes of the type HCC(CH2)nCCCC(CH2)8COOH (n=6 and 12) were synthesized. The solid‐state polymerization of the bulk crystals, mono‐layers on the gas‐water interface, and multilayers were investigated. The diacetylene moieties underwent polymerization upon irradiation by UV or γ‐rays, showing different polymerizability depending on the material form. The polymerization of the terminal acetylene groups was not observed. Enhanced polymerizability and stability of the monolayers on subphases containing LiOH are explained by a proposed model of the monolayers. © 1995 John Wiley & Sons, Inc.
Synthesis and cationic photopolymerization of alkoxyallene monomers
Authors: Crivello J. V. , Yoo T. , Dougherty J. A. 
Published: April 2003

AbstractA series of cationically polymerizable mono‐and difunctional alkoxyallene monomers have been prepared via the straight forward base catalyzed isomerization of the corresponding propargyl ethers. Rate studies conducted using real‐time infrared spectroscopy showed that these monomers exhibit high reactivity in photoinitiated cationic polymerization. Monomers bearing a single alkoxyallene group undergo rapid polymerization to yield crosslinked polymers indicating that both double bonds react during polymerization. A mechanism has been proposed that explains this observation. © 1995 John Wiley & Sons, Inc.
A Nd‐carboxylate catalyst for the polymerization of 1,3‐butadiene: The effect of alkylaluminums and alkylaluminum chlorides
Authors: Wilson David J. 
Published: April 2003

AbstractThe ternary neodymium‐based catalyst for the polymerization of 1,3‐butadiene, Nd(versatate)3/Ali‐Bu2H/tert‐butyl chloride, has been examined with respect to the effects of a range of alkylaluminums and alkylaluminum chlorides. Using either pre‐formed or in situ catalysts, observations pertaining to catalyst activity and physical state and the characteristics of the final polymer are discussed. The catalyst activity series with the type of alkylaluminum was found to be: Aln‐Pr3 ≫ Aln‐Dodec3 = Aln‐Oct3 = Aln‐Hex3 > Ali‐Bu2H > Ali‐Bu3 > AlEt3 ≫ AIMe3. Polybutadiene cis content was found to vary with the type of alkylaluminum used. Pre‐formed catalysts using methylaluminum chlorides as chloride source were found to be the most active; AlMe2Cl chloride gave the highest activity. The activity of in situ catalysts prepared using alkylaluminum chlorides was found to be independent of alkylaluminum chloride structure. Polybutadiene prepared using catalysts based on different alkylaluminums and alkylaluminum chlorides was found to decrease in cis content with conversion. © 1995 John Wiley & Sons, Inc.
Fundamental studies of grafting reactions in free radical copolymerization. III. Grafting of styrene, acrylate, and methacrylate monomers onto cis‐polybutadiene using benzoyl peroxide initiator in solution polymerization
Authors: Huang Nai‐Jen , Sundberg Donald C. 
Published: April 2003

AbstractBenzoyl peroxide (BPO), due to its higher radical reactivity as compared to AIBN, is known to promote grafting onto cis‐polybutadiene. Switching from AIBN to BPO initiator made a dramatic difference in the extent of grafting for styrene and methacrylate monomers, but only a modest difference for acrylate monomer. For styrene and methacrylate monomers, graft site formation is due to BPO initiator radical attack onto the backbone via allylic hydrogen abstraction. Significant levels of grafting are achieved and depend upon the relative concentrations of monomer and backbone polymer but not upon the level of initiator. For acrylic monomer, graft site formation was found to be due to polymer radical attack at the double bond in the backbone. Abstraction of allylic hydrogen also occurs but results in retardation of the overall reaction rate. Graft level was dependent upon initiator and back‐bone polymer concentrations but not upon monomer concentration. The effective role of the initiator is only to produce polymer radicals; the BPO has no direct role in the formation of effective graft sites. © 1995 John Wiley & Sons, Inc.
The association of aqueous phenolic resin with polyethylene oxide and poly(acrylamide‐co‐ethylene glycol)
Authors: Xiao Huining , Pelton Robert , Hamielec Archie 
Published: April 2003

AbstractComb copolymers formed from acrylamide and poly(ethylene‐glycol) methacrylate macro‐monomer (PAM‐co‐PEG) were compared to poly(ethylene oxide) (PEO) with respect to hydrogen bond complex formation with water‐borne phenolic resins. The behaviors of the two types of high molecular weight polyethers were similar. Complex formation gave a transient increase in viscosity followed by precipitation. Copolymers with pendant PEG chain lengths ≥ 9 formed complexes with phenolic resin whereas PEG homopolymer with a molecular weight of 2000 did not form a complex. For both copolymer and high molecular weight PEO, the tendency of the complex to precipitate increased when the pH was decreased from 7 to 4. Acridine orange, a cationic dye, bound to the phenolic resin and, after the addition of PEO, yielded visible complex gels with diameters about 20 μm. © 1995 John Wiley & Sons, Inc.
The conformation and dynamics study of amphoteric copolymers, P(sodium 2‐methacryloyloxyethanesulfonate‐co‐2‐methacryloyloxyethyltrimethylammonium iodide), using viscometry, 14N‐, and 23Na‐NMR
Authors: Yang Jung Hwan , John Mu Shik 
Published: April 2003

AbstractSolution conformations and dynamic mobilities of novel amphoteric copolymers were studied for aqueous solutions of p(sodium 2‐methacryloxyethanesulfonate‐co‐2‐methacryloy‐loxyethyltrimethylammonium iodide) [P(NaMES‐co‐METMAI)] as a function of com‐position, concentration, and addition of HCI or KCI. As HCI or KCI was added successively to 5 w/v% copolymer solutions, the reduced viscosities of the solutions were reduced except the 1:1 copolymer solution. The dynamic mobility of the cationic side chain was estimated with the quadrupolar 14N‐NMR relaxation technique. The motion of the interacting coun‐terion, Na+, was studied by Poisson‐Boltzmann electrostatic theories and the quadrupolar 23Na‐NMR. Since the intramolecular 1:1 ion pair between MES‐ and METMA+ acts as an effective charge‐screening factor, the copolymers P(NaMES‐co‐METMAI) behave as ordinary polyelectrolytes with the exception of the 1 : 1 copolymer. © 1995 John Wiley & Sons, Inc.
Crosslinked poly(ethylene oxide) modified with tetraalkylammonium salts as phase transfer catalyst
Authors: Tsanov T. , Vassilev K. , Stamenova R. , Tsvetanov C. 
Published: April 2003

AbstractRadiation crosslinked poly(ethylene oxide)s (PEO) modified with two tetraalkylammonium salts: allyldimethyldodecylammonium bromide and ethylmethacrylate dimethyldodecylammonium bromide were prepared. They have been characterized by elemental analysis, IR, 1H‐NMR spectra, and DSC measurements. Their activity as phase transfer catalysts (PTC) in the model displacement reaction of 1‐bromooctane with aqueous sodium cyanide were studied. The reaction kinetics were followed under pseudo‐first‐order conditions. Small amounts of onium salt inserted into the PEO network gave rise to a five time increase in the rate constant. The recovered catalysts could be re‐used without loss of activity. © 1995 John Wiley & Sons, Inc.
Surface graft polymerization of glycidyl methacrylate onto polyethylene and the adhesion with epoxy resin
Authors: Zhang Junfeng , Kato Koichi , Uyama Yoshikimi , Ikada Yoshito 
Published: April 2003

AbstractSurface graft polymerization of glycidyl methacrylate (GMA) was carried out onto a high‐ density polyethylene (PE) sheet pretreated with corona to introduce peroxides onto the PE surface. Graft polymerization of GMA was effected by UV irradiation of the coronatreated PE in the presence of monomer solution without the use of any photosensitizer. The graft layer was found by staining the PE cross section to localize in the surface region of PE. The physical change in the PE surface was characterized by scanning electron microscopy, while the chemical changes due to the GMA graft polymerization were assessed by the dynamic contact angle, FT‐IR, and x‐ray photoelectron spectroscopy (XPS) measurement. The peroxide formation by corona exposure was confirmed by the XPS measurement after derivatization with SO2. The epoxy groups introduced onto the PE surface by the GMA graft polymerization were reactive with water (in the presence of HCI) and amines. The adhesion between the GMA‐grafted PE and an epoxy resin was studied by means of a shear strength test method. The GMA‐grafted PE exhibited strong interfacial adhesion with the epoxy resin, compared to the original and corona‐treated PE. The adhesion strength of the GMA‐grafted PE was nearly two times higher than that of the corona‐treated PE. This strongly suggests that the enhanced adhesion between the surface‐grafted PE and the epoxy resin is ascribed to covalent bonding of the epoxy groups on the GMA‐grafted surface to the amines in the epoxy resin. © 1995 John Wiley & Sons, Inc.
Monodisperse polymer beads as packing material for high‐performance liquid chromatography. Preparation of macroporous poly(2,3‐epoxypropyl vinylbenzyl ether‐co‐divinylbenzene) beads, their properties, and application to HPLC separations
Authors: Liang Yi‐Chun , Svec Frantisek , Fréchet Jean M. J. 
Published: April 2003

AbstractIn search for HPLC separation media with new surface chemistries, a styrene‐based monomer, 2,3‐epoxypropyl vinylbenzyl ether, containing reactive epoxide groups has been syn‐thesized and copolymerized with divinylbenzene in a suspension polymerization. The process involves the use of size monodisperse particles that are swollen with monomer and then polymerized in the presence of a porogenic diluent consisting of a mixture of 4‐methyl‐2‐pentanol and octane. The effect of concentration of divinylbenzene on the pore size dis‐tribution and the specific surface area of the resulting uniformly sized porous poly(2,3‐epoxypropyl vinylbenzyl ether‐co‐divinylbenzene) beads has been studied. The epoxide groups of the copolymer have been hydrolyzed and the beads used for reversed‐phase chro‐matography of both small molecules and proteins to show the effect of hydrophobicity of the matrix on the separation properties. Reversed‐phase chromatography of alkylbenzenes follows the expected pattern while for proteins the hydrolyzed beads with the highest content of the crosslinking monomer exhibit a remarkable deviation from the predicted retention characteristics. © 1995 John Wiley & Sons, Inc.
New polymer syntheses. LXXXII. Syntheses of poly(ether‐sulfone)s from silylated aliphatic diols including chiral monomers
Authors: Kricheldorf Hans R. , Masri Majdi Al 
Published: April 2003

AbstractAttempts were made to synthesize poly(ether‐sulfone)s from aliphatic diols or bissilylated diols on the one hand, and 4,4′‐dichlorodiphenylsulfone or 4,4′‐difluorodiphenylsulfone on the other hand. The reaction conditions and the catalyst were varied. Polycondensations of silylated diols with 4,4′‐difluorodiphenylsulfone and powdered K2CO3inN‐methylpyr‐rolidone proved to give the best results. Using silylated isosorbide and isomannide as mono‐mers chiral poly(ether‐sulfone)s were prepared. GPC measurements indicate weight‐average molecular weights in the range of 27×103–200×103. © 1995 John Wiley & Sons, Inc.
Ring‐substituted polyaniline copolymers combining high solubility with high conductivity
Authors: Liao Yun‐Hsin , Angelopoulos Marie , Levon Kalle 
Published: April 2003

AbstractPoly(aniline‐co‐phenetidine)s were synthesized by the copolymerization of aniline and o‐phenetidine (o‐ethoxyaniline). The molar feed ratio of the starting aniline monomers was varied to result in copolymers with different compositions. The actual composition was deduced by integrated proton NMR spectroscopy. The copolymers exhibit excellent solubility characteristics. It was particularly interesting to find that the 20% ethoxyaniline containing copolymer exhibits excellent solubility and yet retains the high conductivity characteristic of the unsubstituted homopolymer. The conductivity of the hydrochloride salt of this par‐ticular copolymer is identical to that of the unsubstituted derivative. However, the copolymer solubility greatly exceeds that of the unsubstituted homopolymer. The copolymer in the base form exhibits very high solubility in NMP and the resulting solutions are exceedingly more stable than those of the unsubstituted derivative. A 10% by weight solution of the 20% ethoxy copolymer in NMP is stable for ⋍ 50 days at room temperature afterwhich a gel is formed as compared to previous reports of ⋍ 3–10 h stability for corresponding solutions of the unsubstituted derivative. © 1995 John Wiley & Sons, Inc.
The interaction of vinyl monomers and poly (ethylene terephthalate) in the presence of various initiators produces a physical mixture, not a graft copolymer
Authors: Xue Thomas J. , Wilkie Charles A. 
Published: April 2003

AbstractThe interaction between poly(ethylene terephthalate) and four vinyl monomers, methacrylic acid, methyl methacrylate, styrene, and vinyl acetate, has been studied using hydrogen peroxide, benzoyl peroxide, azobisisobutyronitrile, and cobalt acetylacetonate as initiators. The ease of addition of the monomer to the polymer follows the solubility of the monomer in the polymer film. No chemical interaction occurs between the PET film and the monomer; rather, the monomer is homopolymerized within the film and forms a semi‐interpenetrating network so that the two homopolymers cannot be separated unless the PET matrix is destroyed. © 1995 John Wiley & Sons, Inc.
Redox polymerization of 2‐hydroxyethyl methacrylate (HEMA). I. Influence of surfactants on polymerization kinetics
Authors: Mathew Jainamma , Mahadevan Venkatanarayana 
Published: April 2003

AbstractOxidation of ferrous orthophenanthroline (FeP) by peroxydiphosphate (PP) in aqueous medium at pH 1 was followed spectrophotometrically. Kinetic analysis has shown that oxidation occurs via the formation of an intermediate complex between FeP and PP. Equi‐librium and rate constants were calculated. Influence of surfactants on the oxidation of FeP by PP was also Investigated. The equilibrium constant for complex formation was found to be higher in the presence of surfactants. The enhanced complex formation has been attributed to the ionic interactions between the charged surfactant and the ionic species in the reaction medium. Polymerization of HEMA initiated by the redox system,FeP/PP, was carried out in aqueous medium, under the conditions of excess reductant over oxidant and excess oxidant over reductant. The polymerization followed different mech‐anisms under these conditions; with excess oxidant, the growing polymer radicals underwent oxidative termination, while with excess reductant, primary radical termination was pre‐ferred. The effect of surfactants on the aqueous polymerization of HEMA using the redox system FeP/PP was also investigated. In addition to the decrease in rate, the polymerization followed a different mechanism in the presence of surfactants, the growing radicals ter‐minated by mutual interaction. © 1995 John Wiley & Sons, Inc.
Penetration of plasma surface modification into porous media. III. Multiple samples exposed to CF4 and C2F4 low temperature cascade arc torch
Authors: Krentsel E. , Yasuda H. , Miyama M. , Yasuda T. 
Published: April 2003

AbstractThe depth and possible mechanisms of the penetration of surface modification into porous media by a low temperature cascade are torch are investigated. Two different modes of such penetration (“flow controlled” and “diffusion controlled”) are evaluated. Three porous samples [stacks of 10 sheets of nonwoven fabrics of poly(ethylene terephthalate)each], placed at an axial distance of 24, 28, and 32 cm from the cascade are anode, are exposed to a low temperature cascade arc torch containing argon and CF4 or C2F4, and surface properties of each of the sheets within treated porous samples are examined by ESCA. It is shown that interaction of chemically reactive species, created in the low temperature cascade arc torch, with the surface is not limited to the surface directly contacted by the torch. The flow controlled penetration is more pronounced for the outer layers, while diffusion controlled penetration is within the inner layers of the porous structure. Substantial differences in the fluorination effect of CF4 (nonpolymer forming gas) and C2F4 (polymer forming gas) discharges for the second and third stacks are observed, that can be explained by the fact that the major effect of the CF4 cascade arc torch treatment is based on the reaction of reactive species with the surface polymer molecules. The effect of C2F4 cascade arc torch treatment is based on the reactions of reactive species with polymers as well as reactions of reactive species themselves at the surface (plasma polymerization). Reactivity of the species created in C2F4 discharge is much higher compared to that created in CF4 discharge, which is one of the major factors influencing penetration trends of low temperature cascade arc treatment into porous media. © 1995 John Wiley & Sons, Inc.
Molecular composite fibers from rigid rod polymers and thermoset resin matrixes
Authors: So Ying‐Hung , Sen Ashish , Kim Peter , Jeor Var St. 
Published: April 2003

AbstractFibers consisting of a rigid rod polymer and thermoset resin matrices were prepared. Poly(benzo‐[1,2‐d : 5,4‐d′]bisoxazole‐2,6‐diyl)‐1,4‐phenylene} (PBO) in polyphosphoric acid (PPA) was blended with isophthaloyl bis‐4‐benzocyclobutene (1) or 2,6‐bis‐4‐benzocyclobutene benzo[1,2‐d: 5,4‐d′]bisoxazole (2), and fibers were spun from these dopes. As‐spun fibers that did not show phase segregation between the two components as examined with an optical microscope, were soluble in methanesulfonic acid (MSA). After heat treat‐ment, the fibers swelled but did not dissolve in MSA. A fiber cross section of heat‐treated PBO‐1 fiber showed well‐dispersed benzocyclobutene polymer domains of 200–500 Å by transmission electron microscopy (TEM). Films cast from MSA solutions of PBO and 2 were homogeneous, and TEM of heat‐treated fiber showed only one phase. A molecular composite fiber was made. Some of these fibers showed 20–30% improvement in compressive strength over unmodified PBO fiber. © 1995 John Wiley & Sons, Inc.
Effect of reaction medium on the ionizing radiation‐initiated cationic copolymerization of styrene derivatives
Authors: Wood Kenneth B. , Stannett Vivian T. , Sigwalt Pierre 
Published: April 2003

AbstractThe influence of reaction medium polarity on the ionizing radiation‐initiated copolymer‐ization of styrene derivatives involving unpaired carbocations is examined. In the copo‐lymerization of nonpolar monomers such as p‐CH3styrene/styrene, a small effect consistent with that predicted by Laidler‐Eyring theory is found. In the copolymerization of nonpolar/polar monomer pairs such as p‐CH3styrene/p‐Clstyrene and styrene/p‐Clstyrene, any such effect is masked by specific solvation phenomena. A competition between such phenomena appears to exist, in which the different cations are dominated by different interactions. The p‐Clstyryl cation appears to undergo strong intramolecular complexation with the penultimate aromatic ring in nonpolar conditions; thus, this cation displays increased se‐lectivity toward monomers best able to disrupt the complex. The p‐CH3styryl and styryl cations do not appear to be subject to such strong complexation; thus, in nonpolar solvent, their selectivity tends towards monomers with the highest cation‐solvating ability. The differing copolymerization behavior of the p‐Clstyryl cation is consistent with the findings of previous investigations of the effect of reaction medium on chain transfer with these monomers. © 1995 John Wiley & Sons, Inc.