最新刊期
卷 ， 期 3 ， 1988
- 摘要：Cyanoethyl cellulose can form lyotropic liquid crystal in some organic solvents above a certain concentration C1*. When phase transition occurs, the optical properties of the solutions very. The existence of the liquid crystalline phase depends on the concentration and temperature of the solutions. The effect of solvent on the formation of lyotropic liquid crystal for the cyanoethyl cellulose is that the critical concentration C*1 decreases with decreasing the polymersolvent interaction parameter x12.
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发布时间：2021-03-19 - 摘要：The structures of polybutadiene and polyisoprene obtained by NdCl3-C2H5OH-AlEt3 catalyst have been investigated with 13C-NMR method. According to the data of chemical shift, the configuration of terminal η3-allylit growing chain is predominated by "tail-to-head" linkage. The temperature of polymerization may change cis-1,4 polymer content. This can be explained by isomerization between anti- and syn-η3-allyl. Since there is a small amount of "head-head" and "tail-tail" linkages in the polyisoprene, 3,4-unit formation in the polyisoprene can be realized.
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发布时间：2021-03-19 - 摘要：Infrared spectra analysis on some of A-stage benzoguanamine-formaldehyde resins with various degree of addition has been performed. The assignment of major IR absorption bands of the resins has been discussed in detail. The thermal curing behaviour of some samples is followed with the techniques of high-temperature IR and differential spectra. From the variation of IR absorption of methylol group, methylene group and dimethylene ether group of cured resins, and the measurement of formaldehyde in the gas evolved in reaction system,the reac-tions of thermal curing of the resins are discussed.
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发布时间：2021-03-19 - 摘要：Three types of light scattering patterns (normal, abnormal and mixed) have been found in PET samples under different conditions of crystallization. In the normal pattern the optical axis is in the direction perpendicular to radius, while in the abnormal one it is the angles of approximate 45° and -45° to the radius. The mixed one is assumed to be the superimosition of the normal and abnormal ones. Based on these assumptions, calculation with a two-dimensional spherulite model for these orientations of optical axes were made ac-cording t Clough's squations. It is shown that the calculated Hv and Vv scattering patterns are satisfactorily in agreement with the experimental ones. Observations with polarized micros-copy have confirmed the model suggested.
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发布时间：2021-03-19 - 摘要：The microstructure-properties of Poly(vinyl chloride)/acrylic copolymer (PVC/ACR) blends have been studied by using dynamic mechanical analysis (DMA), transmission electron microscopy (TEM), stress-strain, and impact testing. Experimental results indicated that the PVC/ACR had a good impact property, and it was evident that the barium-cadmiun stearate-stabilizer was better than the tribasic lead sulfate for PVC/ACR blends. Two transition temperatures of each blend revealed by the DMA spectra showed that they varied as the com-position of the blend changed,therefore the PVC/ACR blends were semi-compatible. TEM re-cords illustrated that they exhibited two phase systems with ACR dispersed as a particle in PVC phase. In the barium cadmiun stearate system when the ACR content was high,the ACR was presented as a network structure in PVC phase. The bland having the above coresponding morphology has a high impact strength.
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发布时间：2021-03-19 - 摘要：The intrinsic viscosity, Mooney viscosity, breaking strength, mill behavior and the dynamic mechanical properties of. ethylenepropylene rubber were investigated in this work. It was found that they are related with the composition, composition distribution, MW, MWD, monomer sequence distribution, and the variation of with MW Micros-tructure was also studied, and some interesting results were obtained.
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发布时间：2021-03-19 - 摘要：Study of the formation kinetics of the simultaneous interpenetrating polymer network (IP-N) at room temperature indicated that castor oil not only reacts with TDI in the formation of polyurethane network, but also takes part in the formation of vinyl copolymer chain. The IPN obtained is rather a grafted semi-IPN than a semi-IPN. Dynamic mechanical sludy of the IPN's showed two Tg's for the IPN containing polystyrene or polymethyl methacrylate but only one Tg for the IPN contatining only polyacrylonitrile, indicating more molecular miing in the latter IPN.
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发布时间：2021-03-19 - 摘要：The authors prepared the high crosslinking copolymeis with purified divinyl benzenes. They also studied in detail the different conditions of preparation, for instance, concentration of crosslinking agent, which affected the pore structure of the copolymers.From experimental results, it is indicated that the copolymers of high crosslinking possess high surface area. An adequate use of the kind and proportion of inert diluente and the ratio of monomers yield products can meet the requirements of industrial purpose.
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发布时间：2021-03-19 - 摘要：The authors studied the pore stability of the high crosslinking copolymers in different state. It is shown that the porous structure of the copolymers changes as a result of the treatment with different solvents. However, the porous structure of the high crosslinking copolymers is more stable than that of the low crosslinking copolymers.As a result of the high stability of the copolymers, which could resist the high impact applied, the authors tried to test it as a carrier for the high performance liquid chromatography.From preliminary experiments,it is shown that the high crosslinking copolymers might be used as a carrier for the high performance liquid chromatography.
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发布时间：2021-03-19 - 摘要：N, N, N', N'-tetramethylbenzidine (NTMB) and 3, 3' 5, 5'-tetramethylbenzidine (TMB) photosensitize the extrusion of SO2 from dibenzyl sulfone (DBS) and degradation of polystyrene-sulfone (PSS). .Both singlet and triplet sensitization are observed. An electron transfer mechanism is proposed to explain the results. The efficiency of triplet sensitization is much higher than that of singlet sensitization.
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发布时间：2021-03-19 - 摘要：The photo-induced grafting copolymerization of N-vinyl-2-pyrrolidone (NVP) to segmented polyetherurethane (SPEU) was studied. The experiments in this work were performed at nitrogen atmosphere and room temperature by using UV light.The effects of concentration of N-VP and light sensitive agent DMT in the grafting solutions and irradiation time on the grafting yield in acid and basic mediums were investigated. The swelling behavior of modified films in water was followed and the surface structure of the films was observed by scanning electron microscope. All the results showed that this kind of photo-induced grafting occured successfully in al-kaline medium. The reason of the alkaline effect was discussed briefly.
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发布时间：2021-03-19
Research Article
- 摘要：It is indicated that vinyl acetate-maleic anhydride copolymer (VAMA) and partial hydro-lyzed polyacrylamide (HPAM) form interpolymer complex in aqueous solution through hydrogen-bonding by means of UV spectroscopy. The composition (unit ratio) of this complex is 1:0.79 (VAMA/HPAM), which is measured by viscosity method.
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发布时间：2021-03-19 - 摘要：The polysaccharide of lentinus edodes and polytictus versicolor has been fractionated by repeated precipitation method. Modified elias cloud-point tiualion method by using an Abbe refrectormeter to determine the cloud-point. It was found that water/acetone (89:11 by volume) is a θ-solvent for the polymer at 25℃.
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发布时间：2021-03-19 - 摘要：The photopolymerization of acrylamide in methanol solution initiated by methylene blue-manganese (Ⅲ) acetylacetonate under visible light is reported, The initiation active species for the polymerization, the photobleaching of methylene blue during the sensitized polymerization process and related mechanism of the initiation are discussed.
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发布时间：2021-03-19 - 摘要：The cyclooctamethyltetrasiloxane (D4) plasma composited membranes were prepared by D4 plasma polymer deposited on the porous polypropylene substrate under the conditions of frequency 13.56 MH power 50-100 W, pressure 0.05-0.2 mbar, low-electrode temperature 20±2℃, deposite time 7-60 min. The oxygen permeation rate Jo2 andd oxygen-nitrogen separation coeff. αo/N of the obtained membranes are 0.5-2×10-5 cm3(STP)/cm2·sec·cmHg and 3.3-3.8, respectively. The formation process of the composited membranes was studied by means of SEM together with the gas peameation properties of the membranes obtained at different reaction time.
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发布时间：2021-03-19 - 摘要：A series of polyarylethersulfone copolymers containing phenolphthalein segments were successfully synthesized (APS, SPS, HPS and CPS). A preliminary study on the copolycondesa-tion process showed that the presence of phenolphthalein component can accelerate the reaction, Copolymers were characterized by Reduced Viscosity, 1H, 13C-NMR and IR. The Tg of copolymers smoothly increases with the increase of the amount of phenolphthalein component. All the copolymers were proved to be random and amorphous by IR, NMR,DSC and WAXD.
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发布时间：2021-03-19
Research Bulletin
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