最新刊期
卷 ， 期 2 ， 1984
- 摘要：There is no crystalline diffraction of wide-Angle X-ray to be discovered in PES, but there is birefringence effect both in its bulk and solution. Its morphological structure unit is a rodlike macromolecule which drrdnges regularly to form domdins, then these domains pack further to form a rodlike submicroscopic structure. The different chain rigidities are due to the different chain structures which induce different dimensions of morphological structure and packing patterns. These morphological structures change with external conditions.All of the above characteristic structures form an important basis for the study of the meso-phase of PES.
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发布时间：2021-03-19 - 摘要：A platinum complex catalyst of silica-supported poly- r -diphenylphosphinopropylsiloxa-ne has been investigated by XPS. The exprimental results suggest that (1) the complex is formed by coodination of lone pair electrons on two phosphorus atoms in poly- r -diphenyl-phosphinopropylsiloxane to a platinum atom in chloroplatinic acid, (2) the catalytic activity of the complex in the hydrogena-tion of aromatics is greatly affected by the P/Pt atomic ratio in the complex and the amount of hydrochloric acid in the reactant,and it also closely relates to the strenght ratio ratio of two Cl2p photoelectron peaks in the complex.
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发布时间：2021-03-19 - 摘要：Linear and cross-linked methyl methacrylamide copolymers containing hydrophilic groups were synthesized by copolymerization of styrene and methyl methacrylate followed by aminolysis. The conditions of reaction were investigated which will enable us to control the degree of aminolysis. Based on the experimental results of elementary analysis, infrared spectrum and 1H-NMR the aminolysis of copolymer was confirmed. It was found that the predictable hydrophilic property of copolymer might be controlled by suitable selection of the ratio of components of St-MMA copolymer,extent f crosslinking and the degree of am-inolysis on thecopolymer.
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发布时间：2021-03-19 - 摘要：In order to evaluate the exact mechanism of an improvement on adhesiveness of poly-ethylene surface by pretreating it with aqueous solution of ammonium peroxydisulfate，stu-dies were conducted by X-ray photoelectron spectroscopy (XPS) and other techniques．From the experimental results，it is shown that oxygen-containing groups such as carbonyl，alde-hyde and carboxyl etc．are produced on the polyethylene surface due tO the oxidative effect of ammoniuln peroxydisulfate．From the results of．XPS analysis．the oxidation depth of high density polyethylene is estimated to be less than 40A，For low density polyethylene，an eyed oxidation layer with a depth between 40 A and 90A is observed．It is shown from the ex-traction experiments，no residue formed by crosslinking is found on the polyethylene sur-face treated by the aqueous solution of ammonium peroxydisulfate．The adhesive strength of the treated polyethylene with epoxy adhesive is apparenray increased．On the basis of the results obtained．the mechanish of the improvement on adhesiveness of polyethylene sur-face by treating it with aqueous solution of ammonium peroxydisulfate was discussed．
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发布时间：2021-03-19 - 摘要：A column chromatographic method was used to separate the hydroxyl-terminated copo-lymers of propylene oxide and tetrahydrofuran (HTPT) according to their functionality. The method is based on the adsorption of HTPT on activated silica gel and subsequent selective desorption by stepwise elution using petroleuon ether-ethyl acetate and ethylacetate-isopropanol solvent mixtures of progressively greater elution power. The number average molecular weight and hydroxyl equivalent weight of the fractions were determined by vapor phase osmometry and infrared spectroscopy respectively.Calculated average functionalities-coincide with those obtained on the whole copolymer by other methods.
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发布时间：2021-03-19 - 摘要：The molecular weights of standard polystyrenes (1000≤M ≤17000) and a series of polyesters containing 5-fluorouracil in the main chain (MM=1000 is possible．The second virial coeffident A2 of low molecular weight polystyrenes increases rapidly as the molecular weight decreases．The relationship between A2 and Mn is A2=const Mn1.40 This suggests that polymers of low molecular weights in dilute solution are fully extended．
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发布时间：2021-03-19 - 摘要：The flow curves of cis 1,4-polybutadiene prepared by four different catalytic systems have been measured by a capillary rheometer.The critical temperature at which the flow curves change from continuousness to discontinusness increased as the cis content increased. It was also found that the long chain branching plays an important role, the better the linearity the higher the critical temperature. The different shapes of extrudate were well explained in the light of the picture that the flow instability can occurs independently at the die-entrance,die outlet and die wall,but the slippage ltself gives no contribution to the irregu-alrity of the extrudate.
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发布时间：2021-03-19 - 摘要：The rolabilities of raw rubbers of high cis 1,4-polybutadienes prepared by four different catalytic systems were examined as a function of temperature and nip width.The critical temperatures at which the flow curves change from continuousness to di-scontinuousness may be used as a criterion of the rolability. The higher the critical temperature, the higher the 2-3 transition temperature, i.e. the better the rolability. But the long chain branching of the polymer has some influence on the rolability, especially at the wide mill nip. The causes of these phenomena have been suggested.
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发布时间：2021-03-19 - 摘要：The copolymerization of acrylic acid and p-divinylbenzene was initiated by r -mercap-topropylsiloxane in the mixture of aqueous sodiumhydroxide solution, carbon tetrachloride, n-hexane and Tween 80 to form a super absorbent sodium polyacrylate which could absorb over 400 times its weight of water.The super absorbent sodium polyacrylate which could absorb near 400 times its weight of water was also prepared by the polymerization of acrylic acid initiated with r -mercapto-propylsiloxane in the presence of dioxane,aqueous sodium hydroxide solution and carbon tetrachloride,but in the absence of any crosslinking agent.
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发布时间：2021-03-19 - 摘要：The rheological behaviour of different PVC resins between 160℃and 200℃ have been studied, their changes in morphology were observed by scanning electron microscopy.The relation of η'-I/T of PVC with different morphology shows the existence of a transition in flow mechanism at 190℃, morphological photographs of scanning electron microscopy gave direct evidence in following sequence: -1μ primary particles and their agglomerates are main flow units in PVC below 190℃, but - 0.05 ℃ sub-primary particles are the flow units in PVC above 190℃and ～0.05μ sub-primary particles are alrea-dy main structural morphology at 190℃.n'increases with temperature when sub-primary pa-rticles are the flow units in PVC.
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发布时间：2021-03-19 - 摘要：Bulk polymerization of acrylonitrile in the presence of Cp2TiCl2.DMSO under the irradiation of light had been investigated. The DMSO efficiently promoted the catalytic process. The rate of polymerization increased with the increase of intensity of light. Polymerization was terminated when the light was taken off. Based on the facts that the rate proportional to [Cp2TiCl2]1/2 , increased with the increase of temperature and there were induction periods in the presence of DPPH, a free radical mechanism was proposed,The rate R,the rate constants k and the activation energy E had also been calculated.
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发布时间：2021-03-19 - 摘要：The crystallization behavior of segmented copolyetheresters having. definite distribution of sequence length of the hard segments was investigated. From the results obtained it is shown that the melt of the Segmented copolyetherester can be regarded as a solid-solution. The crystallization process is analogous to the fractionation process of homopolymer from a solution.
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发布时间：2021-03-19
Research Article
- 摘要：It had been identified by the analysis of the structure that diethyl bis (1,10-phenan-throline) iron Complex was formed by the reaction of ferric acetylacetonate with diethyl aluminium ethoxide in the presence of 1, 10-phenanthroline.Butadiene does not polymerize by Et2Fe (phen)2 alone but polymerize when triethyla-luminium is used as co-catalyst, giving a polymer with mid-vinyl structure. Et2pe (dipy)2 can also polymerize butadiene to high polymer in the presence of triethylaluminium.
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发布时间：2021-03-19 - 摘要：The original process of photooxidation of polystyrene has been studied by fluorescence spectra in this work. Some model compounds were applied to prove that the fluorescence quenching of polystyrene was related to the photooxidation products formed during the process of exposure.
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发布时间：2021-03-19 - 摘要：A chromatographic technique for measuring activity coefficient of solvent at infinite dilution of solvent has been applied to polymer-solvent systems. The solid support is coated with polymer; a small amount of solvent is introduced into the carrier; its retention time is measured and used to calculate the activity coefficient. Basing on activity coefficients at different temperatures, the partial molal heat of mixing of the solvent in the stationary liquid has been calculated. Experimental results are given for benzene,toluene with polysty-rene at temperature range from 76℃ to 180℃.
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发布时间：2021-03-19
Research Bulletin
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