最新刊期
卷 ， 期 3 ， 1985
- 摘要：The rate constants of chain transfer in the polymerization of butadiene with LnCl3-C2H5OH-AlR3 catalysts (Ln=La, Nd, Sm, Gd, Dy, Ho or Y; AlR3 =AT(C2H5)3 or Al(i-C4H9)3) Were evaluated. Analogous to the propagation rate constants described in the early paper these rate constants varies also with the rare earth element used in the catalysts and decreases in the same order. The kinetic study showed that the deactivation of active center initiated with Sm-catalyst was second order. Besides, the mechanism of deactivation of active center has been proposed for the present polyme-rization system.
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发布时间：2021-03-19 - 摘要：The number of active centers and reaction rate constants in the polymerization system of NdCl3-C2H5OH-AlR3-butadiene have been determined by means of tritiated alcohol quenching and kinetic methods. The experimental results show that the number of active centers in this polymerization system lies in the range of 0.5-2.8×10-2mol/ mol Nd with respect to two kinds of aluminium alkyls used. In the investigated range the propagation rate constant does not depend on the nature of AlR3 and polymerization conditions except polymerization temperature, while the rate constant of chain transfer is affected markedly by variations of polymerization conditions.
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发布时间：2021-03-19 - 摘要：The behaviour of photoproteeting of copolymer of styrene-2，2，6，6-tetramethyl-4-piperidinyl methacrylate (PDS) and bis-(2,2，6，6-tetramethyl-4-piperidinyl) sebaeate (Tinuvin-770) for polypropylene have been studied by determination of mechanical pro-perties，molecular weight,ESR and IR of polypropylene．The results showed that there are some analogies and some differences from each other in their behaviour of photopro-teetion，i．e．either PDS or Tinuvin．770 are stabilized by mechanism of stable free radi-eal(>N—O') and also can graft on polypropylene．Their dlfferences of photoproteetion are attributed to forming macromolecule of PDS to improve its heat remstance．extrac- tion resistance and compatibility of PDS with polypropylene．Furthermore，there are about 20 piperidine funetional groups on each PDS molecular chain，that has a slightiy-crosqlinkinng effect．As a result nonvolatile carbonyls are accumulated faster than in the polypropylene containing Tinuvin-770, and strength retention is better and molecu-lar weight decraesing is slower than that of polypropylene confining Tinuvin-770．The measurement of photo-oxidation process of polypropylene showed that the variation of concentration of stable free radical(>-ON') with the increasing of photo-oxidation time is relatively small，especially in later periOd while there is a sharp peak value in the curve for Tinuvin-770 at earlier period．PDS is much more resistant to photolysis so that PDS possesses high photoproteeting effectiveness．
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发布时间：2021-03-19 - 摘要：Chelating resin with macrocyclic mercaptal group supported on maeroporous polystyrene heads was synthesized, which showed good selectivity to Hg2+: its complexing capacity amounted to 30-60 mg Hg3+/g resin, two orders of magnitude greater than for other metal ions such as Ca2+, Zn2+, Ni2+, Pb2+ etc. This resin could restore the activity of urease which had been deactivated by poisoning with Hg2+. Its restoring power was far better than morcapto-resin and common anionic exchange resins. It showed some promise for use as an oral poolymeric detoxifying drug for mercury poisoning.
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发布时间：2021-03-19 - 摘要：The photopolymerization of acrylonitrile (AN) initiated with triphenyl phosphine (TPP) has been studied. The kinetic equation was determined to be Rp = K [AN]1.49 [TPP]0.47 with the overall energy of polymerization (Ea) as 6.16 kcal/mole. Through the fluorescence spectra studies and Stern-Volmer equation analysis, the exciplex formation between the TPP and AN monomer and its initiation mechanism have been proposed tentatively.
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发布时间：2021-03-19 - 摘要：The structure change of crystalline PET．which were crystallized from amorphous species isothermally at various temperatures, was investigated in the course of tempe-rature eIavation by means of DSC，WAXD，SAXS， density measurement and TEM The result shows that besides there are partial melting and reerysta]lization in the pro-cess，its morphology is modified at the salne time including the thickening and enlarge-ment of Iamella，crystals changing from nodular paetdng to typical lamella packing，enlargement and perfeetivn of the crystallite and increasing of regular folding on fold surface．Thus，the morphology formed at isothermal crystallization turns to be more stable which is the cause of the appearence of double melting peaks on DSC curves．
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发布时间：2021-03-19 - 摘要：Morphology of graft copolymer EPE-g-PS, EP copolymer (EPR) with polystyrene (PS) grafts, prepared through maeromer copolymerization, has been studied by transmission electron microscopy(TEM). Results show that the copolymer consists of two-phases with PS microdomains several hundred A in size dispersed in EPR rubber matrix. The mierodomains change in shape from spheric to rod-like as PS-content in the copoly-mers increases. Small amount of EPR-g-PS in EPS+PS blends acts as an "emulsifier", making the microdomains in the blends smaller and the dispersion more homogeneous. Multi-transition behavior of the copolymers confirms the existence of separated phases.
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发布时间：2021-03-19 - 摘要：Structures of nylon 1010 crystallized from both melt and glass states were studied by means of X-ray diffraction ,infrared, polarized optical microscope, dynamic viscoela-sticity and density. It was found that the crystalline structure of nylon 1010 is similar to that of nylon 66. However nylon 1010 crystallized from melt state has much larger distorted littice than that crystallized from glass state in the crystalline region-These problems were discussed with a distorted hydrogen bond plane model.
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发布时间：2021-03-19
Research Article
- 摘要：Double peaks of cold crystallization from DSC tbermograms of PET is found to be connected with the time of storing and the humidity of the storing place. Data from Fourier transform infrared spectroscopy, kinetics of absorbed water and X-ray diffraction indicated that water may take part in plasticization and induced crystallization to the amorphous PET.
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发布时间：2021-03-19 - 摘要：This paper repored a method to measure refractive index of transparant polymer films using Kayleigh interferometer. In the range of-60-120℃, plots of the optical path of light transmission in the polymer vs various temperatures were obtained, and from the same curves Tg, thermal expansion coefficient and temperature coefficient of refractive index of polymer films were estimated. It is shown that optical interference method is a simple and sensitive method.
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发布时间：2021-03-19 - 摘要：Analysis of these experimental results indicated that the crystal structure of polymer fibers differs from that of the small molecular weight substances in that the crystal cell parameters of the former are much more influenced by the internal stresses left in the fiber during the heat setting of the drawn polymer fibers.
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发布时间：2021-03-19 - 摘要：Eperimental studies were performed on a series of degraded PP resins obtained by repeated extrusion for 0 to 8 times at 250℃. By means of a capillary extrusion rheometer with various entry angles and length/diameter ratios (L/D=1, 2, 5, 10, 20, 40) of the capillaries as well as a falling sphere viscometer, the following rheological quantities were measured: zero shear rate viscosity η0, apparent viscosity η, entrance pressure loss ΔP0 and extrudate swell.Both the narrowing of the molecular weight distribution and the lowering of the molecular weight during the degradation process have profound effects on the previous flow behavours. It is suggested that stress t1/2(wheren=n0/2),the value e(e=△Po/2t)and the die swell from a very short die can be used to characterize the existence of high molecular tail of MWD,which greatly influences the processability of the melts.
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发布时间：2021-03-19 - 摘要：A new monomer, p-di(α, α'-dibromo) cyanomethylbenzene, has been synthesized and used by a variety of dehydrobromination reaction to produce a deep colour, insoluble and unfusible polymer. It has ESR signals (g value, 2.0028) and is recognized as a conjugated polymer.
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发布时间：2021-03-19 - 摘要：Polymerization of perfluorobutyne-2 catalyzed by π-bis(benzene)chromium(0) in basic medium affords a lustrous black polymer with an average molecular weight in the range of 1200-1500. It decolorizes potassium permanganate in acetone solution. IK and TJV spectra show that it possesses conjugated double bonds. Its conductivity is found to be τ=8.8×10-11Q-1cm-1. Thermoanalysis illustrates that the polymer is thermally stable in air below 150℃.
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发布时间：2021-03-19 - 摘要：The polyeondensation of 1, 4-phenylenediamine hydrochloride and terephthaloyl chloride with introducing a tertiary amine in NMP-CaCl2 solvent system were studied in detail.High molecular weight PPTA with η1ah higher than 5 was prepared. Properties of this PPTA was the same as the PPTA systhesized from p-phenylenediamine with terephthaloyl chloride, and it was characterized by IR, X-ray diffraction, polarizing microscopy, electron microscopy and TGA.
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发布时间：2021-03-19 - 摘要：Polyvinyl alcohol carriers having active amide and active ester ligand were prepared by acetalization of granular macro-reticular water-insoluble PVA with glyoxylic acid or p-form ylbenzoic aeid, and then reaction with benzotriazole or N-hydroxysuccinimide by using DCCI as condensation agent. The active amides or active esters obtained are easy to react with amines such as n-butylamine or proteines under mild condition.Ovomucoid, an inhibitor of trypsin was immobilized on the above obtained reactive PVA carrier to give an effective affinity-adsorbent for separation of trypsin.
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发布时间：2021-03-19
Research Bulletin
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