bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermally polymerizable bisaryloxy‐bisimido‐bisphthalonitriles containing dimethylsilane, hexafluoroisopropylidene, ether, and keto groups: Synthesis, characterization, and NMR study
Authors: Kumar Devendra , Razdan Uday , Gupta Alka D. 
Published: April 2003

AbstractA proton‐NMR study of the condensation reaction (step 1) of 4‐(3′‐aminophenoxy)phthalonitrile (4‐3′APPN) (I) in an aprotic solvent with various aromatic dianhydrides demonstrated the formation of the corresponding bisamic acid within 5–10 min. There was no effect of the electron affinity of the used aromatic dianhydrides on the time of the condensation reaction and also no charge‐transfer complex formation was indicated. Proton‐NMR study of the synthesized bisaryloxy‐bisimido‐bisphthalonitriles at 250.1 MHz has revealed general findings for their NMR characterization. The coupling constant (J) value for the ortho‐coupled protons of the phthalonitrile ring of the 4–3′‐APPN portion is 8.8 ± 0.05 Hz and that for the ortho‐coupled protons of the aminophenoxy ring of 4–3′‐APPN is 8.1 ± 0.05 Hz. The coupling constant (J) values for ortho‐coupled protons of the dianhydride portion range from 8.1 to 7.5 Hz. Various thermally polymerizable bisaryloxybisimido‐bisphthalonitriles (BBBP) (X, XI, XII, and XIII) containing dimethylsilane, hexafluoroisopropylidene, ether, and keto groups, suitable for the development of thermooxidative stable, void‐free composites, were synthesized by two methods. In method 1,4–3′‐APPN (I) in N,N‐dimethylacetamide (DMAC) was condensed (step 1) with bis(3,4‐dicarboxyphenyl)dimethylsilane dianhydride (SIDA) (II), 4, 4′‐hexafluoroisopropylidenediphthalic anhydride (6FDA) (III), bis(3,4‐dicarboxyphenyl)ether dianhydride (ODPA) (IV), and 3,4,3′,4′‐benzophenonetetracarboxylic dianhydride (BTDA) (V), respectively, to give the corresponding bisamic acids. Thermal cyclodehydration of the intermediate bisamic acid at 160°C gave the bisphthalonitriles. In method 2, the second step of thermal cyclodehydration was performed in situ in refluxing toluene. The characterization of the synthesized bisaryloxy‐bisimido‐bisphthalonitriles (BBBP) was performed using FT‐IR, 1H‐NMR, 13C‐NMR, mass spectroscopy, and elemental analysis. A preliminary study indicated that thermal‐polymerization of these bisphthalonitriles (BBBP) gave tough, thermosetting polymers, useful for high‐temperature applications. © 1993 John Wiley & Sons, Inc.
Hydrosilylation of allyl carbamates by poly(methylhydrosiloxane) and related side‐reactions
Authors: Yu Jian Ming , Teyssie Dominique , Boileau Sylvie 
Published: April 2003

AbstractHydrosilylation of allyl carbamates by poly(methylhydrosiloxane) (PMHS) catalyzed by platinum‐ or rhodium‐based complexes was investigated. About 10% of the carbamate molecules decompose during the hydrosilylation reaction through the cleavage of the carbamate bond. A redistribution process also takes place among the polysiloxane chains resulting in the formation of branched polymers but no crosslinking occurs. A mechanism for this side‐reaction is proposed. © 1993 John Wiley & Sons, Inc.
Novel preparation of electrically conducting poly (vinyl chloride) by photo‐dehydrochlorination from poly (vinyl chloride)/polypyrrole composite film
Authors: Ogura Kotaro , Yano Jun , Kisaka Kotaro , Goto Hideo 
Published: April 2003

AbstractPolypyrrole (PPy) was deposited electrochemically on a platinum plate from a nitric acid solution of pyrrole. The PVC/PPy composite film was finally obtained by casting poly(vinyl chloride) (PVC) onto the PPy electrode from a tetrahydrofuran solution of PVC. The prepared composite film was irradiated at 90°C with a low‐pressure mercury lamp in the stream of hydrogen gas saturated with steam, and the PVC film was dehydrochlorinated, leading to the formation of conjugated polyene. The electrical conductivity (σ) of the PVC film in the irradiated composite film was reveled: σ=2.51 × 10−5S cm−1. By iodine doping, σ was further enhanced up to 5.04 X 10−3 S cm−1. The tensile strength of the irradiated composite film became larger than that of the original PVC film; i.e., the stress at break was: 461 (composite film); 401 kg cm−2 (PVC). These results were brought about by the doping of radical species to the conjugated polyene. The anion, NO−3, doped during the electrodeposition of PPy was photodecomposed to generate radical NO2 and this species was doped to the polyene, resulting in the formation of electrically conductive PVC and mechanically improved composite film. © 1994 John Wiley & Sons, Inc.
Syntheses of new poly (arylene vinylene) analogues: Poly (4,7‐benzofuran vinylene) and poly (4,7‐benzothiophene vinylene)
Authors: Sarker Ananda , Lahti Paul M. , Karasz Frank E. 
Published: April 2003

AbstractThe reaction of bis(4,7‐tetrahydrothiopheniomethyl) benzofuran dibromide with aqueous tetramethylammonium hydroxide leads to a water‐soluble polyelectrolyte which can be film cast and thermolytically eliminated to give poly(4,7‐benzofuran vinylene) (PBFV). Subjection of bis(4,7‐tetrahydrothiopheniomethyl) benzothiophene dibromide to the same reaction sequence gives poly(4,7‐benzothiophene vinylene) (PBTV). UV‐VIS studies show that PBFV has a band gap of 2.76 eV, while PBTV has a band gap of 2.92 eV. These polymers are members of a new class of conjugated poly (arylene vinylene)s, in which heterocyclic pseudoaromatic rings are fused onto a poly(1,4‐phenylene vinylene) backbone. © 1994 John Wiley & Sons, Inc.
Polyimides with alicyclic diamines. II. Hydrogen abstraction and photocrosslinking reactions of benzophenone‐type polyimides
Authors: Jin Qiu , Yamashita Takashi , Horie Kazuyuki 
Published: April 2003

AbstractPhotosensitive polyimides with alicyclic diamines and benzophenone moiety were prepared by reactions of 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride (BTDA) with diamines in aprotic solvents, followed by thermal or chemical imidizations. Among them the polyimide from BTDA and bis(4‐amino‐3‐methylcyclohexyl) methane (DMDHM) can be dissolved in several organic solvents such as dichloromethane, tetrachloroethane, and N‐methyl‐2‐pyrrolidone (NMP). In order to compare properties of the polyimides with alicyclic diamines with those of corresponding aromatic polyimides, the UV absorption spectra and fluorescence spectra of these polyimides and their model compounds were investigated. No occurrence of charge transfer at photoexcited states was ascertained for the polyimides with alicyclic diamines. The hydrogen abstraction and crosslinking during photoirradiation have been studied to learn the influence of the elimination of charge transfer process in these photosensitive polyimides. The quantum yield of hydrogen abstraction for the model compound of alicyclic polyimides is 0.56 in THF measured with HPLC. The quantum yield for the photocrosslinking reaction of the solvent‐soluble polyimide with alicyclic diamine, PI(BTDA/DMDHM), was determined to be 0.004 in air from gel permeation chromatography (GPC) measurement, which is four times higher than that for photosensitive polyimides with aromatic diamines. © 1994 John Wiley & Sons, Inc.
Synthesis and characterization of styrenic polymers with pendant pyrazole groups. II
Authors: Ameduri Bruno , Boutevin Bernard , Malek Fouad 
Published: April 2003

AbstractThe synthesis of styrenic monomers that have pyrazolic or bipyrazolic pendant groups is described. Their homopolymerization and their copolymerization with maleic anhydride (MA) and N‐(3‐acetoxy propyl) maleimide is reported. The monomers were prepared from the Williamson reaction between 2‐pyridine carbinol, hydroxy monopyrazole, hydroxy bipyrazole, and chloromethyl styrene. The homopolymerizations of such styrenic monomers were tried under different conditions, which led to low molecular weight polymers with a high polydispersity. However, alternating copolymers were obtained using maleic anhydride or N‐(3‐acetoxy propyl) maleimide as comonomers, as shown by 1H‐NMR, elemental analysis, and reactivity ratios r1 and r2. Furthermore, the hydrolysis of the acetate function of different copolymers was performed quantitatively. Unlike the acetoxy copolymers, such products do not have any glass transition temperature. Thermogravimetric investigations have shown that these copolymers exhibit good thermostability. © 1994 John Wiley & Sons, Inc.
Preparation, characterization, and mesophase formation of esters of ethylcellulose and methylcellulose
Authors: Guo J.‐X. , Gray D. G. 
Published: April 2003

AbstractA range of mixed ether‐esters of cellulose was prepared from partially substituted ethylcellulose and methylcellulose. The 13C‐NMR analysis of ethylcellulose with a DS of 2.5 indicated that the hydroxyl groups at carbon six of anhydroglucose units were completely substituted. Acetylation of the ethylcellulose under different conditions yielded (acetyl) (ethyl) cellulose (AEC) samples with acetyl degree of substitution ranging from 0 to 0.5. Fully substituted (propionyl) (ethyl) cellulose (PEC) and (acetyl) (methyl) cellulose (AMC) were also prepared. Chiral nematic liquid crystals were formed in these mixed ester/ethers of cellulose in concentrated solutions of acidic solvents. The critical concentration for the phase separation of the cellulosic solutions depended on the nature of the substituent, the degree of substitution, and the solvent at a given temperature. Methylcellulose solutions in trifluoroacetic acid and dichloroacetic acid form chiral nematic liquid crystals with a left‐handed helicoidal structure. The acetylated methyl cellulose samples did not show the reversal of handedness with increasing acetyl content that was previously observed for the corresponding ethylcellulose samples. © 1994 John Wiley & Sons, Inc.
Synthesis of polyesters having quaternary ammonium groups in the side chains and preparation of their blends with poly(vinyl alcohol)
Authors: Wang Chonghui , Nakamura Shigeo 
Published: April 2003

AbstractTriethyl‐2,3‐propanediolammonium chloride (TPC) was prepared and used for the preparation of polyester and copolyesters having quaternary ammonium groups in the side chains. The polycondensation of isophthaloyl dichloride with TPC and other dihydroxy compounds was performed by the organic phase/organic phase interfacial polycondensation method using N,N‐dimethylacetamide/n‐heptane or trimethyl phosphate/n‐heptane as reaction media in the presence of tetramethyl ethylenediamine. Blend films were prepared from these polyesters and poly(vinyl alcohol) by casting from aqueous or aqueous NaOH solution. The electrical conductivity of the blend films is remarkably affected by the moisture content and in the order of 10−5 ∼ 10−8 S/cm in the presence of moisture. © 1994 John Wiley & Sons, Inc.
Synthesis and characterization of poly(ethylene oxide‐co‐ethylene sulfone)s and their precursors: Poly(ethylene oxide‐co‐ethylene sulfide)s
Authors: Zhang Tianhong , Litt Morton H. , Rogers Charles E. 
Published: April 2003

AbstractThree poly(ethylene oxide‐co‐ethylene sulfide)s with oxygen to sulfur ratios of 2/1, 2/2, and 1/2 were prepared by phase‐transfer catalyzed polycondensations of (1) sodium sulfide and 1,2‐bis (2‐chloroethoxy)ethane, (2) 1,2‐ethanedithiol and 1,2‐bis(2‐chloroethoxy)ethane, and (3) 1,2‐ethanedithiol and 2‐chloroethyl ether, respectively. A buffered solution with pH between the pKa of the monothiol (RSH) and the pKa2 of the dithiol (HS–R–SH), or H2S, was needed to obtain high molecular weight polymers, which suggests that nucleophiles transfer and react as monoanions rather than dianions. These poly(ethylene oxide‐co‐ethylene sulfide)s were oxidized completely to poly(ethylene oxide‐co‐ethylene sulfone)s using 3‐chloroperoxybenzoic acid as oxidant. Both the final polymers and the precursors have regular sequenced structures and are semicrystalline. As expected, their glass transition temperatures and melting points increase and solubilities decrease with the decrease of ether oxygen to sulfur ratio. © 1994 John Wiley & Sons, Inc.
Synthesis and characterization of poly(ester‐sulfone)s
Authors: Zhang Tianhong , Litt Morton H. , Rogers Charles E. 
Published: April 2003

AbstractAliphatic and aromatic‐aliphatic poly(ester‐sulfone)s were synthesized by the transesterifications of diphenyl adipate and diphenyl phthalates (ortho, meta, para) with two sulfonecontaining diols, 1,3‐bis (3‐hydroxypropylsulfonyl) propane (Diol‐333) and 1,4‐bis(3‐hydroxypropylsulfonyl) butane (Diol‐343). Based on DSC and WAXD studies, the aliphatic homopoly(ester‐sulfone)s are semicrystalline at room temperature and liquid crystalline at elevated temperature, while their copolymers with alkanediols are liquid crystalline. The liquid crystalline phase formation in aliphatic poly(ester‐sulfone)s is attributed to the strong dipole‐dipole interactions between sulfone groups. The aromatic‐aliphatic poly(estersulfone)s from diphenyl phthalate (ortho) and isophthalate (meta) are amorphous. They are soluble in trifluoroacetic acid and m‐cresol at room temperature, and DMF, DMAC, and DMSO at elevated temperature. The aromatic‐aliphatic poly(ester‐sulfone)s from diphenyl terephthalate are semicrystalline and are soluble only in trifluoroacetic acid. For a given diol, the glass transition temperatures of aromatic‐aliphatic poly(ester‐sulfone)s increase from phthalate to isophthalate to terephthalate. This is because the flexibility of the benzene ring in the polymer backbone decreases from ortho to meta to para substitution. As a comparison, polyesters without sulfone groups were synthesized from two alkanediols, 1,9‐nonanediol and 1,10‐decanediol, and the diphenyl esters. The poly(ester‐sulfone)s have glass transition temperatures 60–80°C higher than the corresponding polyesters without sulfone groups, due to the strong dipolar interactions between sulfone groups. © 1994 John Wiley & Sons, Inc.
Synthesis of graft polymers from an ozonized ethylene vinyl acetate copolymer (EVA). I. Study of the radical polymerization of styrene initiated by an ozonized EVA
Authors: Fargere Thierry , Abdennadher Mohamed , Delmas Michel , Boutevin Bernard 
Published: April 2003

AbstractPolymers can be ozonized with an ozone/oxygen mixture to create peroxides and hydroperoxides on the polymer chain. These heat‐sensitive functional groups can be used to initiate radical polymerization of vinyl monomers and give graft copolymers. The properties of these copolymers are well described in literature; however, we notice that available data concerning decomposition rate constants are inconsistent. Decomposition rate measurements, time of assay of free radicals and stability of the ozonized polymers do not give the same results. In this work, we studied the kinetics of the styrene polymerization initiated by an ozonized ethylene vinyl acetate copolymer. Consequently, the f·kd product can be calculated (f is the efficiency and kd the decomposition rate constant). The ozonized copolymer is not similar to usual radical initiators. The initial viscosity of the solution has an important effect on the calculation of the kinetic values. Activation energy and Arrhenius coefficient are different than the one obtained for the usual initiators. © 1994 John Wiley & Sons, Inc.
Quantitative theory of iniferter polymerization. I. Kinetics
Authors: Kuchanov S. I. 
Published: April 2003

AbstractOn the basis of a rather general scheme of elementary reactions of radical polymerization conducted in the presence of iniferters, kinetic equations have been derived describing this process over the whole range of monomer conversion. Proceeding from thorough analysis of these equations, different regimes of polymerization have been found that differ in values of order with respect to the iniferter and monomer of the initial rate of polymerization. Conditions for kinetic parameters have been formulated whose fulfillment predetermines that radical polymerization occurs according to the iniferter mechanism. © 1994 John Wiley & Sons. Inc.
Synthesis of hydroxyl‐containing polyimides derived from 4,6‐diamino‐resorcinol dihydrochloride and aromatic tetracarboxylic dianhydrides
Authors: Moy T. M. , Mcgrath J. E. 
Published: April 2003

AbstractHigh Tg polyimides containing pendant phenolic hydroxyl groups were synthesized in high molecular weight via one‐step solution polymerization of the dihydrochloride salt of 4,6‐diaminoresorcinol with various commercially available dianhydrides. Polymerization proceeds via initial dissociation of diaminoresorcinol dihydrochloride to hydrogen chloride gas and diaminoresorcinol, followed by rapid dissolution of diaminoresorcinol and polymerization with the dianhydride monomer to afford soluble, fully‐cyclized polyimide. The resulting poly(hydroxy‐imide)s, which contain two phenolic hydroxyl groups per repeat unit, were soluble in amide solvents and dilute aqueous bases, displayed reasonably high glass transition temperatures and a high degree of water uptake. © 1994 John Wiley & Sons, Inc.
Study on chain transfer to acetic anhydride of THF polymerization
Authors: Li Fang‐Xing , Wang Hong‐Jun , Li Chun‐Gang , Ma Ke‐Qin 
Published: April 2003

AbstractIn the presence of acetic anhydride, the catalyst containing protons makes the polymerization complex.1,2 Thus, whether the living center, during the polymerization process of THF, transfers to the acetic anhydride is a difficult problem to answer. In this article, CH3COSbCl6 is used as the catalyst to avoid the interference of the protons. It is found that acetic anhydride is an effective chain transfer agent, by the experiment at different temperatures for two systems in the presence or absence of acetic anhydride, and by the comparison of kinetic behavior. In the system without acetic anhydride at the temperature of 7, 15, and 22°C, the propagation rate constants of THF, kp are 7.90, 14.23, and 23.35 10−3L/Mol.S, respectively. In the presence of acetic anhydride, kp are 1.51, 2.85, and 4.98 10−3L/Mol.S; and ktr are 2.04, 3.59, and 6.49 10−4L/Mol.S, respectively. © 1994 John Wiley & Sons, Inc.
Novel polystyryl resins for size exclusion chromatography
Authors: Li W.‐H. , Stöver H. D. H. , Hamielec A. E. 
Published: April 2003

AbstractNew size exclusion chromatography (SEC) resins based on a crosslinker having independent vinyl groups have been produced and compared with SEC resins based on divinylbenzene‐55 (DVB). 1,2‐Bis(p‐vinylphenyl)ethane (p,p‐BVPE) and its meta‐isomers were suspension‐copolymerized with p‐methylstyrene in the presence of different porogens to give particles of about 5 μm average diameter. The porous particles were slurry‐packed into stainless steel columns for SEC evaluation. Calibration curves were obtained using narrow disperse polystyrene standards with molecular weights ranging from 580 to 3,040,000. The calibration curves for the new BVPE resins covered wider useful molecular weight ranges than those for comparable divinylbenzene resins. Particle size, surface morphology and the properties of pores were studied using a Coulter Multisizer II, scanning electron microscopy, nitrogen adsorption, and mercury porosimetry. © 1994 John Wiley & Sons, Inc.
Polymer‐supported Ziegler–Natta catalysts. II. Ethylene homo‐ and copolymerization with TiCl4/MgR2/poly(ethylene‐co‐acrylic acid) catalyst
Authors: Sun L. , Hsu C. C. , Bacon D. W. 
Published: April 2003

AbstractA novel polymer‐supported titanium‐based catalyst shows high activity and nondecaying kinetic profiles for ethylene polymerization. The presence of 1‐hexene comonomer drastically increases the catalyst activity, exhibiting a similarity to the MgCl2‐supported catalysts. However, the nondecaying kinetic profiles of copolymerization distinguish this catalyst from the latter. Infrared analysis indicates that the transition metals were immobilized on the polymer support via functional groups. The effects of polymerization conditions on catalyst activity have been assessed. Characterization of the resulting polymer product by means of 13C‐NMR, DSC, and SEM demonstrates a branch‐free structure with high melting point, high crystallinity, and high molecular weight for the ethylene homopolymer. The reactivity ratios of ethylene‐1‐hexene copolymerization are evaluated from 13C‐NMR analysis data. © 1994 John Wiley & Sons, Inc.
Electrically conductive pseudo IPNs of linear poly(carbonate‐urethane) and crosslinked polychloroprene
Authors: Chen Z. J. , Xue Yongpeng , Frisch H. L. 
Published: April 2003

AbstractA number of pseudo IPNs of poly(carbonate‐urethane) (PCU) and crosslinked polychloroprene (CR) have been synthesized and characterized. The single phase morphology of these novel pseudo IPNs has been confirmed by DSC measurements and electron microscopy. The room temperature electrical conductives of homopolymers and pseudo IPNs have been investigated for both undoped and iodine‐doped samples. © 1994 John Wiley & Sons, Inc.
Synthesis and radical crosslinking reaction of poly (vinylcyclopropanone acetal)s
Authors: Sanda Fumio , Takata Toshikazu , Endo Takeshi 
Published: April 2003

AbstractSynthesis and radical crosslinking reaction of poly (vinylcyclopropanone acetal)s (4), volume change on the crosslinking, and thermal analysis of 4 and the crosslinked polymers were carried out. 4was prepared by the reaction of 1,1‐dichloro‐2‐vinylcyclopropane with sodium dialkoxides. Radical crosslinking of 4a was carried out in the presence of AIBN, BPO, or DTBP at 60, 80, or 120°C, respectively. 4a afforded no dichloromethane‐insoluble part in the crosslinking in chlorobenzene but afforded in 37% yield in bulk at 120°C. On the other hand, 4b afforded dichloromethane‐insoluble part in 33% yield in the crosslinking in chlorobenzene at 120°C. Volume shrinkage of 4a and 4b on crosslinking at 120°C was 4.11 and 3.55%, respectively. Glass transition temperatures of the crosslinked polymers obtained from 4a and 4b were 28 and 163°C, respectively, which were 32 ∼ 49°C higher than those before crosslinking. © 1994 John Wiley & Sons, Inc.
Synthesis and photoinitiated cationic polymerization of 1,2,3‐tris(1‐propenoxy) propane
Authors: Crivello J. V. , Bratslavsky S. A. 
Published: April 2003

AbstractThe synthesis of 1,2,3‐tris (1‐propenoxy) propane (GTPE) was carried out by the rearrangement of 1,2,3‐tris(2‐propenoxy) propane (glycerol triallyl ether, GTAE) and the Z: E isomer composition of the GTPE was determined using gas chromatography and 1HNMR. The photoinitiated cationic polymerization of the GTPE was studied using realtime infrared spectroscopy (RTIR). Employing the data from these studies, rates of polymerization for the respective E and Z propenyl ether double bonds were calculated. The rate of incorporation of Z‐double bonds of GTPE into the crosslinked polymer matrix is 1.6 times that of E‐double bonds. The effects of oxygen and several other free radical polymerization inhibitors were investigated. An increase in the photogel time and decrease of the gel‐content in the presence of these inhibitors implicates the involvement of free radicals in the process of the generation of propagating cationic centers when diaryliodonium salt cationic photoinitiators are used. © 1994 John Wiley & Sons, Inc.
The effects of substituent size and molecular weight on the liquid crystalline properties of poly(2‐alkyl‐1,4‐phenylene terephthalate)s
Authors: Majnusz Jerzy , Lenz Robert W. 
Published: April 2003

AbstractA series of low molecular weight, thermotropic poly(2‐alkyl‐1,4‐phenylene terephthalate)s was prepared by the solution polycondensation reaction of terephthaloyl chloride and alkylhydroquinones containing n‐alkyl substituents of increasing size from methyl to dodecyl. Samples of the low molecular weight polymers so obtained were also further polycondensed in the solid state to obtain high molecular weight polymers. The liquid crystalline phase behaviors and textures were determined, and the effects of polymer structure and molecular weight on these properties are discussed. All of the polymers obtained formed thermotropic, nematic mesophases, which were less stable for the lower molecular weight polymers, as expected, than were the mesophases formed by the higher molecular weight polymers. © 1994 John Wiley & Sons, Inc.