最新刊期
卷 ， 期 5 ， 1987
- 摘要：Functional monomers such as NTAAM, NDMAAM, NPMAAM were synthesized. Binary initiation systems consisted of eerie ammonium nitrate (CAN) and these functional monomers could initiate acrylamide (AAM) polymerization. It was found that AAM could graft copoly-merize onto macromolecules having paratolylcarbamoyl and phenylcarbamoyl pendant groups, such as PNTAAM, PNTMAAM, PNPMAAM and copolymers 1-6. The formation of graft copolymer has been verified by its water absorption %, contact angle with water, the X-ray pho-toelectron spectrometry and the scanning electron microscopy hotographs. The reaction mecha-nism was proposed and the main reactive site of graft copolymerization initiated by ceric ion would take place predominantly at the functional pednant group.
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发布时间：2021-03-19 - 摘要：The initial free radicals of cyclic amine species formed through the reaction of peroxgdisul-fate with cyclic amines such as morpholine (MP), piperidine (PD) and their N-substituted derivatives were studied by spin trapping technique and ESR spectra. It was confirmed by ESR spectra and the amino end group analysis that the morpholino and piperidino free radicals were responsible for initiation of winyl polymerization in addition to sulfate radical (HO3SO) when peroxydisulfate/alicyclic secondary amine system was used as initiator,and the cyclic aminoalkyl radcal was one of the initial free radicals in the system when peroxydisulfate was reacted with tertiary cyclic amines such as N-methyl morpholine (NMMP),N-ethyl morpholine (NEMP).
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发布时间：2021-03-19 - 摘要：On the basis of Fich's diffusion law, a method of calculation of gas diffusion coefficient in polymer from the value of inflection point on differential diffusion curve is derived, by which the attainment of steady state is not necessary, thus experimental time can be greatly reduced. This method was tested on nylon 1010 and nylon 1010/polyethylene/poly (ethylene-g-maleic anhydride) blends. The results calculated are in uniform with that from time-lag and t1/3 methods, and accord with experimental values.
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发布时间：2021-03-19 - 摘要：The environmental stress crack resistance (ESCR) and impact strength of high densky polyethylene (HOPE) are increased by blending butyl rubber (HR). In case the IIR content is less than 50%, the crystal lattice, crystallinity, melting point of HOPE in the blends keep unchanged, the amount of IIR entering into the amorphous region between HOPE lamellae increases with IIR content. In HOPE lamellae a few IIR segments are wrapped in along the direction of lamellae thickness, they act as if the connecting rods which tie up the HDPE lamellae and lead to outstanding impact strength and ESCR of the blends.
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发布时间：2021-03-19 - 摘要：In this paper, we study the separation properties of five polymer membranes i.e. polyphenyl-as-triazine, polyphenylquinoxaline containing ether linkage, polyphenylquinoxaline, polyimide and" polypyrrone for O2, N3, H3, CO2 CO and CH4. Though the gas permeabilities P of these membranes for O2 are only 10-10cm3 (STP) .cm/cm2.sec.cm Hg in magnitude, but their selective separation factors αo2/N2e greater than 5. It is worth notice that the selective separation factors of polypyrrone αH2N2. αH2/co and αH2/CH4 are equal to 1181,1166,875 respectively. To the authors knowledge,these have not been reported in previous literature.
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发布时间：2021-03-19 - 摘要：The kinetics of styrene polymerization on TiCl3-Al(C2H5)3 catalysts in toluene, n-heptane or toluene-n-heptane mixtures were studied. A mathematical model of monomer diffusion controlled polymerization in globle polymer particles containing catalyst was designed, which explained quantitatively the decay of polymerization rate caused by diffusion barrier and the different rate decays in different mediums. The kinetic curves treated with the model show that polymerizations in good solvent for polystyrene are less diffusion controlled than in non-solvent,and the catalyst containing particles in good solvent systems are smaller than in the non-solvent systems.
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发布时间：2021-03-19 - 摘要：The copolyester-polyether (or polyesteramide-polyether) multiblock copolymers with meso-genic units in the hard segments were synthesized by the acidolysis of a polyesterpolyether multi-block copolymer with p-acetoxybenzoic acid (or p-acetamidobenzoic acid) followed by polycon-densation reaction through the acetoxy (or acetamido) and carboxyl groups. The optically an-isotropic textures of these mukiblock copolymers in the melt have been studied.
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发布时间：2021-03-19 - 摘要：A new inorganic polymer catalyst, rhodium complex of silica-supported polytitazane (ab-briviated as Ti-N-Rh) has been prepared. It has been found that Ti-N-Rh could catalyze the hydroformylation of cyclohexene at 120℃ and under 60 atm. (CO/H2 = 1), the yield of cyclo-hexyl formaldehyde amouted to 95%. The stability of Ti-N-Rh is very good for the reaction,. and the total turnover numbers amounted to over 20,000.
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发布时间：2021-03-19 - 摘要：In the presence of beta-nucleating agent propylene blocks in ethylene-propylene block co-polymer can crystallize to beta-crystalline form with high purity. Effect of crystallization temperature on the relative content and structure of the beta-form and melting behavior in the sample were investigated. It was found that two kind of beta forms were obtained, depending on the crystallization temperature. The mechanical behavior of beta-phase sample was also studied and compared with that of alpha form.
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发布时间：2021-03-19 - 摘要：The uni-axial stretching of amorphous poly (ethylene terephthalate) (PET) film has been studied in the tcmperature range of 78一112℃ bv means of the temperature scanned dynamical mechanical loss curve of the stretched film．Amorphous PET films stretched at lower temperatures were crystalline，caused solely by straininced crystallization which took place when the stress-train curve stated to show an incease (strain hardening) after yielding．Amorphous tilms stretched at higher temperatures，arround 90℃ or higher，remained amorphous and optically isotropic．The latter resulted from complete relaxation of the Iocal chain orientation during hot streching．while the global orientation of the chain could only be relaxed by rubbery flow which would be rather slow．The thermal relaxation of the g lobal chain orientation have been studied by stress relaxation of the stretched amorphous film with fixed ends．At lower temperatures the films after almost complete relaxation remained amorphous．At higher temperatures the film started to crystallize during stress relaxation after the stress had relaxed to a value below 10％ of the initial stress．FTIR studies showed that this stressrelation time corresponds to the induction period of crystallization under such conditions．
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发布时间：2021-03-19 - 摘要：The polymerization of fourteen N-phenyl unsaturated dicarboximides were studied for the selection of capping agents of "PMR" polyimides. The correlation between the polymerization activities and the structure of dicarboximides was discussed. The kinetics of five monoethyl ester of unsaturated dicarboxylic acids possessing higher polymerization activities with aniline in absolute ethanol were also investigated and their rate contants, activation energies and half lives were obtained.
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发布时间：2021-03-19 - 摘要：An electrically conductive composite polypyrrole-polycaprolactam (PPY/Nylon 6) was obtained by the electrochemical polymerization of pyrrole in a polycaprolactam matrix. These composite films are much easier to peel off than pure PPY film and are flexible and self-supporting. The measured electrical conductivity of PPY/Nylon 6 composite film from Pt electrode is 119 S/cm. The measured tensile strength and elongation are 7195 psi and 52.8%. The PPY/Nylon 6 composites were characterized by scanning electron microscopy.also.
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发布时间：2021-03-19 - 摘要：Synthesis and free radical polymerization of four alkyl substituted six-membered cyclic ke-ten ascetals; 4-methyl-2-methylene-l, 3-dioxane (II), 4,6-dimethyl-2-methylene-1,3-dioxane (IV), 5, 5-dimethyl-2-methylene-1,3-dioxane (VI), and 5,5-diethyl-2-methylene-1, 3-dioxane (VIII) have been studied. Results indicated that introduction of methyl or ethyl substituents into β-position of oxygen atom in ring slightly effected ring-opening polymerization, but substituents at a-posi-tion of oxygen atom showed significant effect on the competition of polymerizations,that the ring-opening favored to form a more stable radical species. A complete ring-opening polyme-rization of (IV) was occured in a dilute benzene solution and in the presence of DTBP at 120℃ to give a polymer with polyester structure.
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发布时间：2021-03-19 - 摘要：The synthesis, electrochemical behaviour, IR and "C-NMR of soluble polyaniline (PAn) have been investigated. The voltammograms cor.dottivity and IR spectra indicate that the main molecular structure of the soluble PAn is similar to that of unsoluble PAn "C-NMR spectra of the soluble PAn in DMF-d7 are obtained.
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发布时间：2021-03-19 - 摘要：Graft copolymerization of acrylonitrile onto coal humic acids was studied in aqueous medium at low pH. Several redox initiating systems were tested, among them, K2S3O3-FeSO4 and K2S2O3-ascorbic acid pairs are promising. Degree of grafting of humic acids of different types differs not widely, and usually comes up to more than 75%. A portion of grafted humic acid, 20% in average, splited down under strong alkaline condition. It is supposed the grafting at the carboxylic group of humic acid is through ester linkage. This fact may be noteworthy for the purpose of preparing driling mud additives through saponification of such copolymers.
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发布时间：2021-03-19 - 摘要：Caprolactam can be polymerized to a high elongation nylon-6 by alkaline catalyst, without ther use of activator. The polymerization can take place even when the temperature is lower than 220℃ or as low as 160℃. The effect of the polymerization temperature on the properties of the formed polymer has been investigated. The optimum condition of polymerization temperature is around 200℃. The polycaprolactam thus prepared has high impact strength and high elongation which is all over 200% and as high as 363%. Comparing with the conventional MC nylon-6,it has lower melting point,glass transition temperature,specific gravity and percent crystallinity.
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发布时间：2021-03-19 - 摘要：The effect of the length of blending rime and the effect of a second blending of dynamically vulcanizing EPDM/PP on its morphology, PP crystallinity (xc), effective network chain density (vs) and tensile properties were studied by SEM.TEM, DSC and WAXD. EM observations indicated that the dispersed EPDM diminished in size with length of blending time and the second blending. Xc of PP decreased with blending time but increased after 13 minutes, whereas tensile strength of the blends was observed to behave in the opposite direction. Vc continued to decrease in the blending. Xc and Ve became lower but tensile strength higher after the second blending at various blend ratios. Tensile strength was linked to the fine dispersion of EPDM particles in PP and the interfacial interaction of EPDM with the amorphous part of the semicrystalline PP.
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发布时间：2021-03-19 - 摘要：A polymer-bound palladium (II) chloride complex has been prepared by the reaction of palladium chloride with a chelate resin of 8-aminoquinoline. Refluxing the complex in methanol-water solution, it gives a polymer-bound mixed valence palladium catalyst. The activity and selectivity for hydrogenation of the olefins with the above catalyst have been studied. It was found that the polymer-bound mixed valence palladium catalyst is more active and selective for hydro-genations of olefins. The catalvst is also stable. There is no obvious loss of palladium of the catalyst.
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发布时间：2021-03-19
Research Article
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