最新刊期
卷 ， 期 2 ， 1987
- 摘要：Difference in thermal behaviour of presumed polypropylene-b-polyethylene block copoly-mers (PP—PE) and corresponding PP+PE blends was studied．Different views jn the litera-ture were unified in our observation that faster cooling rate yielded only one exothermal peak for the blends，while slower cooling rates revealed both PP and PE exothermal peaks．Further details on when a single or double exothermal peaks would appear are discussed．Melting and crystallization temperatures for both PP and PE in blends were found to be a few degrees higher than for PP and PE in block copolymers．Thus，thermal analysis can be used to identify PP-PE block copolymers．These phenomenon and the lower △H-values of PP and PE in block copolymers than the △Hr-values of pure homo-PP and -PE (for PE even more so) are explai-ned in terms of restricted block movement due to covalent bond between blocks and of crystalli-zation processes in block copolymers．The presence of block structure in the PP-PE samples studied is inferred．
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发布时间：2021-03-19 - 摘要：We have synthesized poly (ethylene terephthalate) (PET), with two series of different catalysts in the process of esterexchange reaction.The catalyst effects the crystal behavior of PET was studied by DSC. The crystal behavior of PET by different catalysts is characterized by supercooled degree, superheated degree, peak of melt crystallization ect. It has been shown that the electronegativity (or lg β1) of metallic element involved in catalysts not only influence the cause of activity of catalyst, but also affect the crystal of PET in some way. It is probable the rate of forming crystal embryos is speeded up in presence of cetain metallic ion of catalysts.
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发布时间：2021-03-19 - 摘要：This paper reports the IR spectroscopy of CPE synthetized by solid-phase chlorination pro-cess under different conditions．We also emphat ically discussed the structural characterics of CPE，chlorineted by two steps．It was observed that the modification of a characterizistic crys-talline structure and chlorine distribution on-(CH2)n-chain segments．The results showed that the solid-phase chlorination mainly occured in amorphous regions under the lower temperature conditions，and also formed a block structure with a high and low (or non-) chlorinated chain segment in CPE．If the solid-phase chlorination was processed in two steps，the crystalline re- gion would be destroyed with a higher degree．The chlorination process is limited any longer the amophous region，and whether the destruction of crystalline structure is related to the degree of chlorination in the second step．Even if its chlorine contents is all the same as to CPE．But only variation with chlorination degree in two steps，therefore the structure will be signif-cantly different．
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发布时间：2021-03-19 - 摘要：Ni(II) naphthenate in gasoline or toluene shows a light green color，which is the result of absorption in the red and blue parts of the spectrum，the three bands due tO the spin-allowed d-d transitions are 403，680，and 1170 nm respectively．Ni(II) complex is octahedral complex． The naphthenate ligand attached tO Ni(II) can be exchanged for an alkyl group on isobutyla-luminium if Al／Ni in the mixture containing metalalkyl and naphthenate does not excecd the value of 0.53．At higher ratio (A1／Ni≥O．53)Ni(II) is reduced tO Ni(I) and (Ni(O)．In the mixture of Ni (II)with BF3·OE3 the naphthenate ligand is exchanged for halogen．The reac-tion produces Ni(II) complex，which is traced to the presence of three weak d-d bands and it is found to be octahedral complex as well as Ni(naph)2．The conclusions are analogous to the discussion on the basis of the measuring of magnetic susceptibility of the same nickel cata-lystic system．
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发布时间：2021-03-19 - 摘要：In this paper, the graft copolymerization of acrylamide initiated with eerie salt onto the film of polyester-polyether block copolymer was studied. The film need to preactivate using UV-irradiation before grafting. The graft copolymer was characterized using SEM, ESCA and ATR-IR. A hemoperfusion using minicolumn filled withmicrospheric activated carbon (MSAC) encapsulated with the graft copolymer showed that the graft copolymer has good blood compatibility.
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发布时间：2021-03-19 - 摘要：The long chain branching of polybutadienes was measured with a gel permeation chromatog-raph coupled to an automatically recorting capillary viscometer. In this method the experimental relation (η) (V) was transformed to the calibration curve (η) (VR) for the monodis-perse species. The curve is combined with the universal calibration to proviel the molecular weight distribution and an additional parameter, i.e. g, the average branching foctor in this sample. The critical molecular weight at which long chain branching appear changes with polymerization conditions.
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发布时间：2021-03-19 - 摘要：The effects of ethylene sebacate (ES) content (ranging from O to 15 mol％) on crystallinky, crystallite orientation，crystallite size and long period of annealed (fixed length in 130℃) PET-ES copolyesters fibers were studied by wide-angle X-ray diffraction (WAXD) and smal-langle X-ray scattering (SAXS) methods，and differential scanning calorimetry curve and dyna-mic mechanical behavior were invistigated．The results show a significant decrease of the degree of crystallinity (Xc)，the melting point (Tm)，and the glass transition temperature (Tg) with increasing ES cantent．The crystallite volume increases，but the thickness of crystalline lamellae decreases with rise of the amount of ES in chain molecules．It is shown that the one-dimension two-phase model is not suitable for PET-ES copolymer．And it appears that all the experimental results in the paper can be explain-ed by prevorseks "three-phase model" after some improvemelit．
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发布时间：2021-03-19 - 摘要：Much attention has been paid in recent years to the toughening of isotactic polypropylene (PP)，and blending PP with ethylene-propylene terpolymer (EPT) is one of the most effective ways．In order to further improve the toughness of PP／EPT blend and to enhance the stabi-lity of the dispersed rubber phase，a diblock copolymer composed of PP and ethylene-propylene rubber blocks (PP-EPR) was added into the blend．as it is considered that“forced compatibi-lity” of the two components will be effected through the two chemically bonded blocks，while two-phase structure still remains．Experimental results indicate that PP-EPR is an effective compatibilizer for PP／EPT blend．It not only increased the toughness of the blend，but also decreased the loss of tensile strengths usually accompanying the toughening of plastics with an elastomer，which is very well explained by the changes in morphological structure when an appro-priate amount of PP-EPR was added into the blend．
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发布时间：2021-03-19 - 摘要：Title resins containing 2.30(mmol and 2.57 (mmol functionalgroups have been prepared. The intermediate resin with] adjacent dihydroxyl groups was prepared in a phase transfer catalysis system with high percentage of conversion of functi. onal group. In aq. HC1 solution, the sulfite resin absorbs Pt (II) selectively, title resins absorb Au (III) with high selectivity in the presence of Fe(II), Zn(II), Cd(II), Ni(II), Cu (II), Pd(II), Pt(IV), Pb(II), Mn(II). The sulfite resin has the capacity 126 mg Au(m)/g, separation coefficient Kd=824 (ml/g),and the Au(III) adsorbed can be eluted to 85% with ne eluting. The carbonate resin has the capacity 46.0 mg Au (III)/g,Kd=84.1 (ml/g).The sorption rates were T1/2=1.0h,T1/2=0.8h,respectively.
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发布时间：2021-03-19
Research Article
- 摘要：The polymerization kinetics of di (p-cyanophenyl)ether and di(p-cyanophenyl)sulfone catalyzed with zinc chloride were studied. The polymerization rate constants at different temperatures were obtained. The activation energy of the polymerization is as low as 10.7 and 10.4 Kcal/mol, respectively.
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发布时间：2021-03-19 - 摘要：This paper reported a method to measure moisture swelling of amorphous PET films using Rayleigh interferometer. Plots of the optical path of light transmission in the polymer vs soaking time were obtained, and from the same curves, time dependence of the moisture swelling, saturated (equiliorium) water apsorption and diffusion coefficient of PET films were estimated. These results are in agreement with those obtained by the weighting method. It is shown that optical interference method is a simple but sensitive method for the study of warer absorption and swelling in transparant polymer films.
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发布时间：2021-03-19 - 摘要：N-(4-N', N'-dimethylaminophenyl) acrylamide (DMAPAA) and N-(4-N", N'-dimethyla-minophenyl) methacrylate (DMAPMA) were synthesized directly by the reaction of p-N, N-di-methylaniline with corresponding acrylic acids in the presence of dicyclohexylcarbodiimidc (DCCI). These two monomers .vere polymerized with difficulty by diacyl peroxides such as BPO or LPO, but could be polymerized with hydroperoxides such as t-butyl hydroperoxide, cu-mene hydroperoxide as initiator. The spin trapping technique was used to explore the reaction mechanism of BPO or LPO with DMAPAA at lower concentration in benzene using 2-methyl-2-nitroso-propane as trapping agent.
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发布时间：2021-03-19 - 摘要：Methylene-morpholino-group N-substituted acrylamides, i. e. N-(N'-methylene-morpholino) methacrylamide (MMMA) and N-(N'-methylene-morpholino) acrylamide (MMAA) were syn-thsized and polymerized. It was found that these monomers were hardly polymerized initiated with BPO, but could be polymerized with LPO. The polymerization kinetic equations initiated with LPO were obtained asRp= Kp[MMMP]1.5[LPO]0.5Rp = Kp[ MMAA]1.5[LPO]0.5and the overall activation energies were obtained as low as 13.4 Kcal/mol and 9.2 Kcal/mol respectively. The redox nature of the polymerization of these aliphatic tertiary amino-group N-substituted acrylamides initiated with LPO would be suggested.
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发布时间：2021-03-19 - 摘要：The polymerization of acrylarmde in the presence of coal humic acids was studies with dilatometry, which was carried out in aqueous solution at 60℃ with potassium-peraulfate as sole initiator. Humic acids lengthen induction period and depress rate of polymerization. These influences are pH dependent. The effect is supposed to be concerned with stable free radical, quinone. phenol functional groups wish exist in humic acids.
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发布时间：2021-03-19 - 摘要：The paracrystal, porous and phase structures of the blend acrylic fibers has been investigated. It was found that the blend acrylic fiber in the present work is a kind of matrix-fibril bicomponent porous fiber, phase separation takes place in it. The micropores, formed on the interfaces between two polymer domains, appear to be well oriented in the direction of the fiber axis and elongated into cylinderlike in the same direction. Furthermore, they are not isolated but penetrated, which makes the blend fiber high water retention.
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发布时间：2021-03-19
Research Bulletin
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