最新刊期
卷 ， 期 4 ， 1995
- 摘要：In this paper, [2,6-dimethyl-1,4-phenylene oxidel was modified by trimethyl chlorosilane and triphenyl chlorosilane, and a serfes of silyl-substituted PPO were synthesized. The gas transport behavior in polymeric membrane were studied with changes of group and ratio of substitution. It is found that gas permeability in trimethyl silyl-substituted PPO rises and selectivity decreases, but both decrease in triphenyl silyl-substituted PPO with increasing the ratio of substitutions.Because trimethyl silyl-substitited PPO have similar gas solubility but various diffusivity, difference between gas permeability is mainly caused by gas diffusion coefficient. From relationship between gas permea-bility and polymeric chemical structure, gas diffusion process may be increased in polymer if bulky free groups are introduced into polymeric side chain.
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发布时间：2021-03-19 - 摘要：?methyl, ω-(1,2-epoxy) propyl poly(ethylene glycol)(Ⅱ) was prepared and hydrolyzed to a glycol(Ⅲ) with a pendent poly(ethylene glycol) (PEG)chain. The glycol(Ⅲ) was used as the chain extender in preparing poly(etherurethane) with PEG grafted onto the hard segments (H-PEU).The macromer(II) cationically copolymerized with tetrahydrofuran to give a copolyether (Ⅳ) grafted with PEG chain. Using copolyether(Ⅳ) with about 1.3grafts per molecule, the S-PEU with PEG grafted onto soft segments was synthesized.The S-PEU as well as H-PEU had a soft segment-rich surface as shown by ESCA study. The recalcification times for S-PEU and H-PEU increased 20% and 100%, respectively,as compared with that of ungrafted PEU. With increasing the PEG content the antithrombogenicity increased.
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发布时间：2021-03-19 - 摘要：hotochemical primary reaction and photoinitiated polymerization of MMA with Benzophenone(BP)/Triethylamine(TEA) in dicetyldimethyl ammonium bromide(DCDAB) vesicle solution were studied in this paper. The kinetic experimental results showed that DCDAB vesicles exhibit a large catalysis on the polymerization, leading to an increase in the polymerization rate by four times which is near to the values catalyzed by the ionic micelles. Except the effect of the conventional high local concentration produced by the solubilization this result also should be attributed to the microenviroment effect of interface layer at DCDAB vesicles, where the reaction takes place. It promotes significantly the photochemical primary reaction of BP/TEA and results in increase in the rates of electron transfer (Kir) and proton transfer (Kh) processes. The polymerization product (PMMA) formed in DCDAB vesicles has a reatively high tacticity and was estimated to be about 70% syndio- and isotactic.
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发布时间：2021-03-19 - 摘要：our kinds of alkyl vinyl sulfoxides(RVSO, R = Me, Et, t-Bu, Ph)were synthesized and reacted with poly(vinyl alcohol) in the presence of alkali catalyst by the Michael addition reaction to prepare alkyl vinyl sulfoxide grafted poly(vinyl alcohol)(PVA-RVSO). Permeabilities of various alkyl vinyl sulfoxide grafted poly (vinyl alcohol) membranes for pure SO2, N, and SO2-N2 mixture gas were studied. The results showed that the membranes exhibited high permeability and selectivity for SO2, SO2, permeability and separation factor of these polymer memberanes increased markedly as the size of the alkyl group of vinyl sulfoxide increased. The effects of sulfoxide content of the polymer and the pressure on the SO2 permselectivity of the membranes also were examined.
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发布时间：2021-03-19 - 摘要：he permeability of two polypyrrolone membranes to H2,O2, and N2has been determined over a temperature range of 30-90℃. The introduction of bulky group,-C(CF3)2-, into the backbone of this polymer appears to result in a significant increase in gas permeability coefficient. The permeability changes in this case was primarily due to the alteration of diffusivity factors. This result contributes to the inhibition of chain packing and segmental mobility. The permeability coefficient increased with the rise of temperature, while the selective separation factor decreased correspondingly. Within the temperature range, the effects of tem-perature on gas permeability coefficients can be described well by the Arrhenius form. The apparent activation energy for permeation, Ep, increases as the penet-rant size increases,which follows the expected general trends.
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发布时间：2021-03-19 - 摘要：series of mesogenic monomers and polymers with three benzene rings linked by ester bond were synthesized for the first time by means of radical polymerization. In this type of liquid crystal polymers, rigid mesogens are directly fixed on the main chain backbone of polymethacrylic ester not by flexible spacer. Their glass transition temperatures were very high, indicating showed that these molecular chain have significant rigidity. The liquid crystalline behavior of the polymers was characterized by DSC, pelarized optical microscopy and X-ray diffraction. It was found that all the monomers and polymers were nematic.
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发布时间：2021-03-19 - 摘要：he ionomers of a,co-carboxylato-polybutadiene and α,ω-carboxylate poly (butadieneco-acrylonitrile) with Li+, Na+, K+, Mg2+, Zn2+, A13+ were prepared in toluene. Both the absolute viscosity of the concentrated solution and relative viscosity of the dilute solution of these ionomers were investigated. The ionomers were characterized by infrared spectroscopy, transmission electron microscope, and dynamic mechanical analysis. The results showed that: 1) the maximum absolute viscosity of the ionomer solutions of a,w-carboxylate poly (butadiene-co-acrylonitrile) with different metal ions were related to the species of metal ions and the molar ratio of M/-COOH,2) there were sharp increases in the relative viscosity of the ionomer solutions with increasing concentrations,which were caused by the formation of the ion-cluster in the solutions, 3) the size of the ion-cluster in the ionomers containing different metal ions depended on the species of the metal ions.
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发布时间：2021-03-19 - 摘要：he emulsion graft copolymerization of butyl acrylate onto chitosan was investigated, using KPS/NaHSO3 as a redox initiator, sodium dodecy benzene sulfonate as emulsifier. It was found that the percentage of graft, efficiency of graft and homopolymer depended on chitosan content, KPS/NaHSO3, BA concentrations,reaction time, reaction temperature. The grafted copolymer was identified by IR, SEM,X-ray diffraction diagrams. The films formed from copolymer emulsion were tested and the results show that the elongation ratio of chitosan film will be increased by emulsion graft copolymerization with butyl acrylate.
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发布时间：2021-03-19 - 摘要：The effects of chlorinated polyethylene(CPE) on the kinetic behaviors of suspension-swelling graft copolymerization of methyl mathacrylate(MMA)/styrene(S) in the synthesis of MCS resin were studied. The presence of CPE increases the viscosity of polymeric system and diffusion effect, makes the gel effect much earlier and decreases the maximum rate of copolymerization. CPE gives retardation and chain t'ransfer effects on the MMA/S copolymerization. The former will lower the rate, while the latter lower the molecular weight. In comparison with S,CPE will preferably adsorb MMA and swell with more MMA in a shorter time owing to their similar solubility parameters and specific interaction. It causes the different composition of MMA/S random and graft copolymers. The CPE con-tent,swelling time, conversion and the amount of mercaptan will affect the copo-lymer composition.
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发布时间：2021-03-19 - 摘要：series of highly crosslinked polydivinylbenzene resins were synthesized by suspension polymerization in the presence of toluene and liquid pareffin as porogenic agent. The electrophilic aromatic substitutions of these polymers were studied by changing reaction agent, catalyst and solvent. The results showed that the percentage conversion of reaction of the polymers were lower than those of crosslinked polystyrene. In terms of reaction extents of both isomers poly (p-divinylben-zene) and poly (m-divinylbenzene),poly(m-DVB) is not so high as those of poly (p-DVB).
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发布时间：2021-03-19 - 摘要：as-phase polymerization of ethylene over a prepolymerized MgCl2,supported TiCl4. catalyst was compared with slurry polymerization. An accelerationtype or hybrid-type rate behavior for the slurry polymerization, but a decay-type rate behavior for the gas-phase polymerization have been observed. The difference in the apparent kinetics between these two processes could result from monomer diffusion resistance in the slurry polymerization and overheat effect in the gas-phase polymerization. The measurment of the oxidation states of titanium in the catalyst indicated that more titanium ions were reduced to lower oxidation state in the gas-phase process than in the slurry process. The preepolymerization temperature and yield also remarkably affected the polymerization activity and kinectic behavior.
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发布时间：2021-03-19 - 摘要：Composite polymer networks CPNs, based on hydroxyl terminated unsaturated polyester/polyurethanes were synthesized. The influences of chemical kinetics and phase separation on physico-mechanical properties were investigated. Data reveal that the composite polymer network of unsaturated polyesterlpolyesterurethane(r = NCO/OH = 0.4) is superior to its counterparts from polyetherurethane or polymethylene polyphenyl isocyanate, PAPI in mechanical properties. An optimum CPN can be designed and prepared via controlling soft and hard segment components and composition of network.
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发布时间：2021-03-19 - 摘要：The amorphous comblike polymers based on methylvinyl ether/maleic anhydride alternating copolymer backbone and on oligo-oxyethylene side chains were synthesized according to our previous work．The dynamic mechanical properties of the polymers and their LiClO4 complexes were investigated by means of DDV-II-EA type viscoelastic spectrometry．The results show that the polymers and their LiClO4 complexes possess two type of transition in．the temperature range from 173K to 373K．β-transition of the polymer is assigned to PEO side chains．The temperatu-re of β-transition increase with increasing LIClO4 amount added．a-transition of the polymer is assigned to the polymer main chains．As for the a-transition temperatu-re．when the salt content increases there is a maximum at the ratio of Li／EO being 028．The relation between LiClO4 amount added and conductivity is rather comp-lex．It shows more than one peaks，one is located in the range of ratio of Li／EO less than．014．another one is located at the ratio of Li/EO =．028．The tempera-ture dependence of ionic conductivity was studied Data indicate the Arrhenius re-lationship is not held．But the plot of lgσ against 1/(T—To) shows the unusual dual VTF behavior when using side chains glass transition temperature as To．This is attributed to the a-transition of the polymer main chains．
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发布时间：2021-03-19 - 摘要：Copolymerization of propylene with oxygen-containing monomer, 4-pentenoxyl trimethyl silane(PTMS), was studied under Solyay TiCl3/AI(i-C4H9)ca catalyst system. Poly (propylene-co-pentenol) was synthesized by deprotecting trimethyl silica group, and characterized by IR, NMR method. The effect of polymerization condition, e.g., Al/Ti ratio, temperature etc., on the copolymer composition and yield was studied. The copolymerization kinetics was satisfied with that of propylene with l-olefin. Furthermore, the copolymer was found having good physi-cal properties,such as high melting point,isotacticity, crystallinity, good adhesive ability and antidegrading ability.
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发布时间：2021-03-19 -
A KINETIC STUDY ON EMULSION COPOLYMERIZATION OF BUTYL ACRYLATE AND STYRENE USING CATIONIC EMULSIFIER
摘要：he kinetics of emulsion copolymerization of BA and St using dodecyl dimethyl benzyl ammonium chloride as emulsifier was studied. The effect of the concentration of emulsifier, initiator, monomer and polymerization temperature on polymerization rate(Rp) were investigated in detail; The kinetic equation Rp= K [M]0.72[I]0.63[E]0.96 and the apparent activation energy Ea=79.615kJ/mol were obtained. Some discusion for the reaction oder of reactant in copolymerization system were also given.- 3
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发布时间：2021-03-19 - 摘要：new method was used to synthesize the PbS nanoparticles in polystyrene matrix. Absorption spectra, small angle x-ray scattering(SAXS) and TEM were utilized to characterize the average particle size and the size distribution.The amount of H2S and the initial concentration of Ph2+-containing copolymer affect on nanoparticle size slightly, but greatly for the particle size:distribution. The distribution is getting broad as increasing the concentration of H2S and the Pb2+-containing copolymer. The reaction conditions during the formation of the PbS nanopar--rticles in solution determine the size distribution. The bulk polymerization process has little effects on it. By controlling the reaction conditions properly, an organic optical composite with good transparence was obtained, in which the PbS nanoparti-cles with a narrow particle size distribution were well dispersed.
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发布时间：2021-03-19 - 摘要：olyphophates as liposome preparing materials were synthesized. These new amphiphilic polyphosphates were synthesized by polycondensation of β-bromoethyl dichlorophosphate and α-monostearin in benzene, and then by quaterisation with alkyldimethyl amine. Their chemical structures were comfiremed by IR,1HNMR spectra and elemental analyses. Average molecular weight of polymer prior to quaterisation was determined by VPO method. The nitrogen content from elemental analyses showed that the quaterized polymers containing different content of quaternary ammonium side chain (50-31%). These polyphosphates were used to prepare liposome by using Reverse phase evaporation method. All quaterized poly-phosphates could form large unilamellar liposomes. The diameter of liposome from polyphosphate IIa is 104nm. All the experimental data showed that these am-phiphilic polyphosphates are good materials for preparing liposomes. The encapsulation ratio of 5-Fluorouracil (5-Fu) was determined Encapsulation ratio of 5-Fu is in the range of 25% to 32% Release rate of 5-Fu from liposome was also studied.
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发布时间：2021-03-19
Research Article
- 摘要：ulfonated poly(dimethyl phenylene oxide)(SPPO) has been prepared through the reaction of PPO with fuming sulfuric acid in the media of chloroform.The effect of the amount of sulfuric acid on sulfonation degree has also been discussed. The structure of SPPO was characterized by using FTIR, 1HNMR, 13CNMR and other analysis methods. Conductometric titration, Elemental analysis and 1H-NMR were used to determine the sulfonation degree of SPPO, i. e., the percentage of sulfonated units.
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发布时间：2021-03-19 - 摘要：series of cardo polyaryletlierketones containing alkyl substituents of diffrent kind and number were synthesized by "one-step" solution polycondensation reaction of his (4-nitrophenyl) ketone(DNBP) with phenolphthalein, o-cresophthalein,2', 5', 2", 5"-tetramethylphenolphthalein and thymolphthalein. Their chemical structure and aggregation structure were confirmed by FT-IR, 1H-NMR, differential scanning calorimetry, WAXD and density. The experimental result showed that polymeric free volume and segment flexibility varied greatly with position,king and number of substituents.
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发布时间：2021-03-19 - 摘要：lightly crosslinked hydrogels prepared from 2-N-pyrrolidonoethyl acrylate(PyEA) and 2-N-pyrrolidonoetbyl metLacrylate(PyEMA) exhibited high equilibrium water content (EWC) up to 80.9gb. The Lydrophilicity of P(PyEA-coHEMA) and P(PyEMA-co-HEMA) was much better than that of PHEMA. The release of 5(6)-carboxyfluorescein which acts as a probe from the kydrogels displayed normal behavior controlled by diffusion and the release rate of 5(6)-carboxyfluore.seem appeared to be those of Fickian release kinetics.
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发布时间：2021-03-19 - 摘要：Poly(ester-amide) copolymers of glycolide(GA) and 6(R, S)-methyl2,5-morpholinedione(MMD) were synthesized by bulk ring-opening copolymerization of GA and MMD. The effects of polymerization temperature, time, initiator content, GA/MMD mol ratio in feed were investigated, and the results showed that the optimal temperature, time and initiator/monomers mol ratio are 130t, 48 hours and 0.1 %, respectively. The DSC analysis indicated that with the increase of GA content in the copolymer, the Tg of the copolymer is decreasing, the Tm and crystal-linity are increasing gradually.
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发布时间：2021-03-19 - 摘要：N-[(3-DimetLylamino)-propyll acrylamide(DMAPAA) and N-[(3dimetliylamino)-propyl] methacrylamide(DMAPMA) were synthesized by the reaction of 3-dimethylamino-propylamine with acryloyl and methacryloyl chloride respectively at 0-5℃ temperature. The kinetics of the aqueous solution polylmerization of acrylamide(AAm) by using ammonium persulfate(APS) combined with DMAPAA or DMAPMA was investigated. The rate equations were given as:respectively. The overall activation energies of the polymerization were determined as low as 35.0kJ/mol and 41.0kJ/mol respectively. Based on the end-group analysis results, the reaction mechanism of DMAPAA or DMAPMA with APS was proposed to be similar to the initiation reation of persulfate/tertiary aliphatic amine redox system,and the resulting aminomethyl radicals were responsible for initiation of vinyl polymerization as well as sulfate radical.
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发布时间：2021-03-19
Research Bulletin
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