最新刊期
卷 ， 期 4 ， 1989
- 摘要：The subject of whether or not physical entanglement networks contribute to the elastic mo-dulus of polymer is still at issue．According to the Flory’s swelling theory and theory of rub-ber elasticky，the characterization of chemical crosslinking networks and physical entanglement networks of radiation crosslinked cis-1，4-polybutadiene(cis-PB) as well as influence of ne tworks structure on the mechnical properties were investigated in this paper．Resuks display that the density of physical entanglement networks is much higher than that of chemical cros-slinking networks．With the increasing of radiation dose，the density of chemical crosslin-king is increased，but the number of entanglement is decreased．The relations of crosslinking/entanglement density and constants C1 and C2 of Mooney-Rivlin equation were explored．Results show that the constant C1 is attributed tO chemical crosslinking networks；while the constant C2 is attributed to physical entanglement networks．The physical entanglement net-works mainly contribute to the initial elastic modulus Go of crosslinked polymer for small strain；while the chemical crosslinking networks chiefly contribute to the break strength of crosslinked polymer for the large strain．
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发布时间：2021-03-19 - 摘要：In the solid solution of PMo12-PVAc，a phenomenon of irreversible thermal sensitivity blac-kening and the formation of deepred component in it which arised from thermal chemical reac-tion at 100℃ or 120℃ was studied by XPS and ESR etc．The process of blackening and the deep red component formation are the result of alcoholysis of PVAc in part tO form VA-VAc copolymer first，due to acid effect of phosphomoIybdic acid． Afterwards，when oxidation-reduction occurred，the phosphomolybdic acid was reduced to form not only a part of blue Mi-xed Valence Complex of molybdenum (Vl，V，IV) by VA-VAc copolymer，but also was rcdu-ced further into Mo (III) in part．The hydroxyl of VA-VAc copolymer was oxidized by phosphom01ybdic acid to produce a carbonyl group．This Mo (III) coordinated with the oxy-gen of the carbonyl group of VA-VAc copolymer to form a deep red component of VA-VAc macromolecular metallic Mo (IlI) complex，which brought about these polymer molecule to bind together．Therefore，the system of PMo12-PVAc is an irreversible thermal blackening ma-terial．
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发布时间：2021-03-19 - 摘要：The viscoelastic properties of a set of star-shaped polystyrenes with 4-12 arms were studied in bulk by the tensile stress relaxation method. The zero-shear viscosity 0, the steady-state compliance Jc0 and other Theological parameters were determined from the relaxation modulus master curves. It was found that the zero-shear viscosity and the maximum relaxation time rm were strongly dependent on the size of polymeric molecules and could be described with the unperturbed specific viscosity or with the reduced molecular weight,no and τ1n increased with branch degree. It was directly proved that Joc of star polymers, whose arms are of same length,is independent of the number of arms. The Joc's of star polymers seem to be greater than those of linear polymers having the same molecular weight as span molecular weight of star.
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发布时间：2021-03-19 - 摘要：A new type polymer-supported bidentate sulfide ligands platinum complex, fumed silica-bound poly(4-oxa-6,7-dimethyl-mercaptoheptyl) siloxane platinum complex, has been synthesized starting from 2,3-dimethylmercaptopropyl allylether via hydrosilylation by trimethoxysilane followed by hydrolysis and immobilization with water and fumed silica, then reacting with potassium chloroplatinite in acetone. It exhibited good catalytic activity for the hydrosilylation of olefins by trialkoxysilane, and could be reused several times without loss of its activity. Its structure was characterized by elemental analysis and XPS,and a possible structure pattern has been suggested.
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发布时间：2021-03-19 - 摘要：By the use of polyarized light microscopy, scanning electron microscopy, small angle light scattering ald solvent etching techniques, the experimental study was carried out to investigate the crystalline morphologies of polyphenylene sulfide(PPS) and its blends with polyethersul-fone (PES). It was found that the blending techniques and the composition of the blend has great effects on the blend morphology. The PPS could form transcrystalline under the stress. With the increase of PES portion in the blend, the overall morphology of the binary mixtures (shape,size,structure of the spherulites of PPS and of the PES domains and interspherulite boundary) changed gradually,e.g. a transform from the continuous phase of PPS to the con-tinuous phase of PES,the PES from the interspherulitic regions to intraspherulitic regions,whi-le the spherulite morphologies of PPS became irregular and coarse.
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发布时间：2021-03-19 - 摘要：The sol-gel distribution theory is a powerful tool to deal with the structure of crosslink-ing networks in the molecular level in classical theory. There are two problems, which caused the descrepances between experimental results and classical theory. This paper takes into account the effect of intramolecular reaction to sol-gel distribution and derives equations containing all parameters of reaction successfully. The experimental results with polyester as model compound support the theoritical ones of this paper.
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发布时间：2021-03-19 - 摘要：Rubbery modulus of poly (vinyl acetate)/poly (methyl acrylate interpenetrating polymer networks (PVAc/PMA-IPNs) are determined in dynamic mechanical experim-ents, and calculated according to eq. ER = . Their comparison shows that mutual entanglements obviously exist in PVAc/PMA-IPNs, and that network I dominates the properties related. A discussion is made about the entropy change due to mutual entanglements using Binder'Frisch relationship,△Sent∝N-1c,IN-1/2c,II.
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发布时间：2021-03-19 - 摘要：The effect of the chain structure of carboxylated polypropylene carrier (polypropylene grafted with unsaturated carboxylic acid) on the polymerization rate of acrylonitrile was investigated. The comparison on the initiation activity of vanadyl polycarboxylate (polymer supported catalyst) with vanadyl iso-butyrate (low molecular homologue) and vanadyl sulfa-te (low molecular non-homologue) was made. The experimental results indicated that (1) the cooperation effect exists between the carboxyl groups of (P-COO)2 VO;(2) the chain ef-fect of carrier enhances the cooperation effectof carboxyl groups; (3) the polymerization rate was affected by the d-1-configuration of the chains of polycarboxylic acid,the distance of car-boxyl groups and the mass transfer effect of carrier and (4) under our experimental condi-tions,the mechanism of initiation does not depend upon the chain structure of polymer sup-porters.
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发布时间：2021-03-19 - 摘要：By reactions of p-hydroxybenzoic acid with the chlorides of adipic acid, suberic acid, sebacic acid and 1,10-decanedicarboxylic acid respectively four new diacids, and then their dich-lorides, were obtained. The four diacids were found to be thermotropic.Twelve regular copolyesters were synthesized by solution polycondensations of the four monomers with hydroquinone, chlorohydroquinone, 4,4'-dihydroxy biphenyl. The copolyesters were characterized by polarized microscope with hot stage, DSC and X-ray diffraction. It was found that all copolyesters are thermotropic nematic liquid crystals with wide mesomorphic temperature range. The melting temperature of copolyesters vary from 150℃ to 300℃ with the change in molecular structure of the polymers.
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发布时间：2021-03-19 - 摘要：The new functional resins bearing aminctpyridine group have been synthesized by the ami-nation of closslinked chloromethylated polystyrene beads with aminopyridine．The influence of reaction mediums，the molar ratio of reagents，reaction temperature and reaction time on the quality of the resins have been studied．The contents of functional group of the resins are 3.22—3.71 mmol -NH-C5H4N/g resin．The structures．of aminopyridine resins (APR) are-confirmed by IR spectra and elementary analysis．The sorption capacities of the APR are-614.8—665 mg Au(III)／g [3.12—3.37 mmol Au(III)／g] and 247.1—311.2 mg Pt(IV)／g[1.27—1.60 mmol Pt(IV)/g]，respectively．The complex ratio of functional group to Au(III) and Pt(IV) are 1.0 and 0.48，respectively．The gold (III) adsorbed on 4-APR can be eluted quan-titatively by 2％ aquous solution of thiourea．The resin．can be regenerated and reused．The sorption capacity of regenerated 4-APR for Au (III) is still high to 605 mg Au (III)/g．The sorption selectivity of 4-APR is Pt(IV)>Au(III)>Cd2+>Zn2+>Pd(II)>Mn2+，Cu2+，Fe3+．These resins may be used in industry．
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发布时间：2021-03-19 - 摘要：The kinetics of butadiene polymerization with WCl6-C4H9OH-Al(i-Bu)2OPhCH3 as catalyst was studied. The orders of reaction for the monomer, the catalyst and the cocatalyst were determined respectively and the rate equation of the polymerization was estabilished. At the same time, the activation energy and Arrhenius factor were known. Based on the equation, the polymerization mechanism of the reaction was also put forward.
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发布时间：2021-03-19 - 摘要：A comprehensive thermal characterization of the various stereoregular polymethacylic acid (PMMA) was conducted via mass spectrometry and thermal analysis. The results showed that no glass transition occurred in the range from 30℃ to 200℃of these polymers was observed. Maximun water evolution, due to anhydride formation, and carbon dioxide evolution, due to decarboxylation, occurred at-245℃℃, respectively, in syndiotactic PMAA, but only water evolution at -185℃ in isotactic PMAA. The relationship between the thermal stability and stereoregula-rity of PMAA was discussed. The activation energy of the dehydration was obtained.
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发布时间：2021-03-19 - 摘要：The morphology of a crystallizable polymer (PCL) in its compatible mixture with uncrys-tallizable polymer (SAN) has been investigated. The crystallinity of poly (e-caprolactone) (PCL) with poly (styrene-co-acrylonitrile) (SAN) has been measured with DSC. By means of cross- polarized optical microscopy and Hv light scattering, spherulites could be observed in the some PCL/SAN systems. The results from X-ray diffraction (WAXD) indicated that the unit cell dimentions of PCL are not changed due to the presence of SAN,but small angle X-ray scattering (SAXS) data showed that the long period between interlamellar regions incre-ases within increasing concentration of SAN. It is believed that the SAN molecules are trap-ped with the spherulites and rejected in interlamellar regions.
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发布时间：2021-03-19 - 摘要：Carbon-13 spin-lattice relaxation time (T1) and nuclear Overhauser factor (NOE) series of 1,2-polybutadiene samples with different microstructures in four different solvents were measured at 50.3 MHz. The data were fit by using Schaefer's asymmetrical logx2 distribution. The relationship between solvent effect on 13C NMR relaxation and the structure of 1,2-polybudiene was studied. It was found that with the increase of the difference of solubility parameters between polymer and solvent (A S), the extent of cooperative segmental motion of the polymer in solution tends to be easier and spin-lattice relaxation rate (1/T1) becomes greater. When 1,2-unit content decreases and main chain becomes more flexible,the effect of solventon 13C-NMR relaxation becomes more considerable. NMR relaxation parameters are more sensitive to the variation of structure in good than in poor solvents.
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发布时间：2021-03-19 - 摘要：When the mole ratio of ammonium peroxydisulfate to aniline is 1:1 to 2:1, polyaniline which is synthesized chemically has a high yield and conductivity. When ammonium peroxydisulfate is present in more excess, it leads to marked decrease in the conductivity of polyaniline. This is due to the fact that ammonium peroxydisulfate is a strong oxidizing agent, which oxidizes various intermediate to produce different products and causes further oxidation of polyaniline. Although various oxidizing agents can raise the electrode potentials of sam-ples of polyaniline. their conductivities and electrochemical activities decrease markedly.This is caused by the further oxidation of polyaniline. In order to maintain a high electrochemical activity of polyaniline,common presence of polyaniline and strong oxidizing agents should be avoided.
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发布时间：2021-03-19
Research Article
- 摘要：The relationship between ideal copolymerizating behavior and the nature of reactive species of anionic copolymerization in nonpolar solvent has been inherently analyzed. The quantitative expression of in O'Driscoll-Kuntz theory has been unambiguously exploited and elucidated. It is postulated that system of anionic copolymerization in nonpolar solvent becomes "ideal" copolymerization system, only if reactive species coexist in dimeric and monomeric. Only in these cases O'Driscoll-Kuntz theory is adaptable.
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发布时间：2021-03-19 - 摘要：Bromo- and chloropoly-4-methylpentene-l were obtained from the macromolecular reactions of PMP with chlorine and bromine respectively. The influences of reaction conditions, the contents of bromine and chlorine in halo-PMP and the natures of bromine and chlorine themselves on the gas permeation properties were discussed.
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发布时间：2021-03-19 - 摘要：The kinetic character of polymerization of methyl methacrylate at high conversion was studied by means of simulation method of an approximate curver The corresponding kinetic equations were obtained, which Were simple and clear. The models were in better agreement with experimental results.
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发布时间：2021-03-19 - 摘要：The graft copolymerization of N-methacryl-N'-methyl-opiperazine onto segmented polye-therurethane (SPEU) film by Go60-r-preirradiation has been studied. It is found that the grafting time varies with structure of different chain extenders. The grafted substrated become opaque, the contact angle drops down and from SEM photographs with salient micrograph showing grafts of macrochain on the surface of SPEU film.
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发布时间：2021-03-19 - 摘要：N-ethylacrylamide (NEA),N-n-propylacrylamide(NNPA),N-iso-propylacrylamide (NI-PA), piperidylacrylamide(PRA),N,N-diethylacry/lamide(NDEA)(and N,N-dimethylacrylamide (NDMA) monomers and the hydrogels of their copolymers with N,N'-methylene-bis-acrylami-de (BiS) have been synthesized. It was found that PNEEA, PNNPA, PNIPA, PPRA and PNDEA hydrogels undergo a discontinuous phase transition during, temperature variation. The effects of monomeric structures, composition of the starting monomeric mixture and the polymerization temperature on the formation,structural heterogeniety and swelling characteris-tics of the hydrogels have been systematically studied. The relative reactivities of Bis and NIPA and the cause of the structural heterogeneity were proposed.
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发布时间：2021-03-19 - 摘要：Photopolymerization of acrylonitrile sensitized by aryl ketones combining with aliphatic tertiary amines or aryl amines has been studied. Among fluorenon-9(FL), acenaphthenequinone. anthraquinone, p-benzoquinone and benzophenone, fluorenon is the most effective when it combines with aliphatic tertrary amine or DMAEM to form the photo-redox system for the acrylonitrile (AN) photopolymerization. From the kinetic study for the photopolymer ization of AN sensitized by FL-DMAEM system, the polymerization rate is proportional to 0.27th po-wer of DMAEM concentration,0.27th power of FL concentration and 0.64th,1.74th power of AN concentration performed in DMF,benzene as solvent respectively. The overall activa-tion energy for the polymerization was obtained as 6.6 kcal/mol. The mechanism of the pho-topolymerization of AN sensitized by using PF-DMAEM system as photo-sensitizer may be via the formation of 9-hydroxy-9-fluorenyl free radical and DMAEM free radical under the UV irradiation. The latter would cause the polymerization mainly.
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发布时间：2021-03-19 - 摘要：Dynamic dielectric coefficient and dynamic mechanical modulus of bis(p-toluene solfona-te) of 2,4-hexadiyne-1,6-dioI(TS) and its polymers with various degrees of polymerization were measured from 123K to 283K. Anomalies of the dynamic dielectric coefficients e11 of TS and PTS along their molecular stacking direction corresponding to their low temperature phase transitions were observed, from which the phase diagram of TS-PTS system was constructed. But the dynamic mechanical modulus ?1 has not be effected by the phase transition.
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发布时间：2021-03-19 - 摘要：N-acryloyl-N'-phenylpiperazine (APP) and N-methacryloyl-N'-phenylpiperazine (MPP) were synthesized by the reaction of N-phenylpiperazine with corresponding acryloyl chlorides. The solution of these polymers display the fluorescence phenomenon, but these monomers do not. APP and MPP can be photopolymerized under the UV irradiation. The rate equation of MMA polymerization initiated by APP and BPO is given as RP = [APP]0.5 [BPO]0.5 [MMA] . The redox initiation system would be formed by the. combination of APP and BPO.APP not only initiates the polymerization of MMA ,but also incorporates into the MMA polym-er chains.
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发布时间：2021-03-19 - 摘要：The copolymerization of butadiene (Bd) and styrene(St) based on Co(nap)2-Al2 Et3 Cl3 Catalyst under different polymerization conditions was studied. The polymerization products contained a littie amount of Bd-St oligomer or St homopolymer besides high molecular weight Bd-St copolymer. The chain structure of the copolymer was determined by IR and 13C-NMR.
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发布时间：2021-03-19
Research Bulletin
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