最新刊期
卷 ， 期 6 ， 1986
- 摘要：NaHSO3-O2-MnSO4, a new initiator system used for the polymerization of acrylamide (AM), has been suggested. The kinetics of the polymerization of AM initiated with this initiator system have been studied and the mechanisms of polymerization have been discussed. The poymerization of AM can be rapidly initiated by this initiator system at room temperature and the average molecular weight of polyacrylamide obtained was about 10 millions. For comparison, NaHSO3-O2 and other initiator systems have been also studied.
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发布时间：2021-03-19 - 摘要：Six new networklike thiacrown ether polymers (NTCPs) were synthesized by a new method, which is the copolymerization of ethylene glycol bisglycidyl ether or diethylene glycol bisglycidyl ether with 2-alkoxymethylthiiranes. The structure of these polymers was studied with IR, DTA, elemental analysis and scanning electron microscope. It is shown that these polymers have very high complexing capacities with potassium and sodium ions and have good phase transfer catalysis activity.
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发布时间：2021-03-19 - 摘要：A modified Ruland's method is presented for the calculation of PET fiber crystallinity. By applying the method, we can get rid of the effect of imperfectivity in crystal structure on the value of crystallinity, so that the value can really represent the percent content of crystal part in samples and possesses the correct meaning. The effect of many factors on the diffraction intensity profile is considered, meanwhile a new method for resolution of amorphous halo is given, and a FORTRAN program is also written for the calculation of crystallinity by the use of microcomputer. The results are satisfactory.
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发布时间：2021-03-19 - 摘要：Eight N-substituted carbazole compounds had been synthesized by different methods. Their IR and NMR spectra were measured. UV spectra of their solution in CCl4 were recorded. The photoinitiation activity of polymerization for methyl methacrylate with these compounds were estimated. Contents of N-allylcarbazole in polymers of methyl methacrylate were analysed.
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发布时间：2021-03-19 - 摘要：Polycations and polyanions of polyvinyl alcohol with various degree of substitution were prepared by acetalization of polyvinyl alcohol with aldehyde compounds and then, neutralized or quaternized with methyl iodide. The corresponding polyion complexes were obtained by mi-xing the aqueous solutions of these polycations and polyanions. The solvation behaviour of these polyion complexes were investigated.
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发布时间：2021-03-19 - 摘要：The solution properties of cis-polyisoprene (PIP) polymerized by lanthanide complex catalyst were studied with viscosity, osmotic pressure, light scattering and GPC methods. The re suits indicated that the molecular chain of PIP is linear. The constants of the Mark-Houwink equation of PIP, Kw and α, have been determined in toluene, chloroform, tetrahydrofuran and hexane, respectively. The experimental GPC curves of PIP fractions were consistent with the theoretical curves from the logarithmic-normal distribution function. The monodispersed [n]-M equations were established from te polydispersed correction factors,qw. The mean-square end-to-end distances obtained from lightscattering are consistent with the calculated values of Flory's method. The unperturbed mean-square end-to-end distances obtained from Stock ma-yer and Fixman's method are basically consistent with the published data.
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发布时间：2021-03-19 - 摘要：A polymeric method was explored for the preparation of polyester-polyether multiblock copolymers using polyesters and polyethers as starting materials. The mechanism of the reaction and the effect of the segment structure on it, the segment sequence of the block copolymers prepared have been studied. It has been shown that to the polymeric method the degree of compatibility between starting polyester and poly ethers is of paramount importance which determines not only the compositional homogeneity of the block copolymers formed but also the success of the polymeric method to get the block copolymers of the expected structure.
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发布时间：2021-03-19 - 摘要：We examined the polyvinylcabazol (PVK) with diazide as a deep UV resist and found the sensitivity of PVK is markedly increased by adding a small amount of diazide. The sensitivity of PVK containing 5% of diazide is about 30 times more sensitive than the PVK resist itself exposed to UV disinfect lamp. A practical exposure times 7 s was achieved for PVK-diazide, whereas exposure times of 210 s was required for PVK. The high sensitivity of PVK-diazide is mainly attributed to photosensitive crosslinking action of diazide. Images of 1.0μm lines of the pattern are obtained from the deep UV contact exposure.
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发布时间：2021-03-19
Research Article
- 摘要：Polystyrene-DVB (4%) copolymer beads is combined with anhydrous A1Cl3 and TiCl4 (1:1) in CS2 to form a stable complex containing 11.4% of chlorine, in which the ratio of the both metals is about 2:1 (Al/Ti = 2/1). It correspond to (6.42×10-4 mol A1Cl3 +3.21×10-4 mol TiCU)/l g. complex beads. The complex can be used to catalyze a lot of organic synthesis reactions in high yield, such as esterifications, acetalizations, ketal formations, etherifications and the Friedel-Crafts alkylations. The activity of PS-Al/Ti is greater than PS-AlCl3 and PS-TiCl4[4-7].It is important to note,that the complex PS-Al/Ti as a catalyst can be used repeate-dly with high yields.
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发布时间：2021-03-19 - 摘要：Rheological investigation on a series of unvulcanized polybutadiene elastomers of different processability has been carried out by means of a capillary extrusion rheometer. It is found that the processability of unvulcanized polybutadiene can be correlated with the occurrence of unsteady flow and the Wall stress dependence of the dimensionless number e characterizing the entrance elongational elasticity which has been found to be sensitive to the branching structure and the molecular weight distribution of the samples. Interpretations based on the structural data ofunvulcanized polybutadiene were discussed.
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发布时间：2021-03-19 - 摘要：The poly-1,2-butadiene prepared with FeCl3-(i-C4H2)3Al-phen catalyst system (Fe-), as with MoCl4OR-(i-Bu)2AlOR' system (Mo-), is also amorphous. For different 1,2-unit content poly-l,2-butadienes, both thermo-oxidative exothermic peak-temperatures on dynamic DSC curves and induction times determined from constant temperature experiments increase with increasing 1,2-unit contents.The exothermic peak disappears for the sample hydrogenated high cis-l,4-polybutadiene, but an endothermic peak at -120℃ appears, corresponding to the melting point of PE. The thermo-cross-linking exothermic peak temperatures of poly-1,2-butadienes decreased with increasing yinyl group content in macromolecult. The peak areas on DSC curves of samples poly-1,2-butadiene after hydrosilylation with (CH3)3SiH in nitrogen atmosphere were decreased. The apparent thermo-oxidative activation energies for polymers prepared by Fe-and Mo catalyst system are 88-93,99-105kJ mol-1 respectively,and their thermo-cross-linking acti-vation energies are 164-185kJ mol-1. These results show that thermo- and thermo-oxidative stabilities of these polymers prepared with differen catalyst system are similar.
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发布时间：2021-03-19 - 摘要：Reacting cross-linked chloromethylated polystyrenes on 2,3-dimercaptopropanol (BAL) and sodium hydroxide under phase-transfer condition, a new type of insoluble polymer support containing a sulfhydryl and a hydroxyl group was synthesized (Ⅲ) (sulfhydryl capecity = 2.5 mmol/g). This BAL-resin being made to monoprotect symmetrical dialdehydes (terephthalal-dehyde), an aldenhyde-resin was obtained (Ⅳ) (aldehyde group capacity =1.2 mmol/g). under the catalysis of phase-transfer, in benzene-wate system at room temperature and sodium hy-droxide as base,the free aldehyde group reacted on Witting reagents to give a p-formylstilbenes (VII) (yield=85.4%).
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发布时间：2021-03-19 - 摘要：With BPO as an initiator in solution; the comb-copolymer of PSt macromer and vinyl acetate was synthesized. The composition and branching degree of comb-copolymer were deter mined by IR spectroscopy. It is suggested that a reasonably accurate estimate of components and branching degree would be given by the equations respectively:A700/A1740=0.4194Cst/CVAC+ 0.1469 and A700/A1740 = 0.12n + 0.0155. When Mn of Macromer is not the standard 20000, the branching degree of graft copolymer is n'=n (20000/Mn), where Mn is the numeral average molecular weight of macromer usedin the process of copolymerization, n is branching degree per 1000 VAC units.From the experimental evidence available,it was found that branching degree of graft co-polymer depends on Mn of macromer. When the monomer feed ration and Mn of macromer changed slightly,the branching degree did not change basically;when Mn of macromer was re-duced,the branching degree of graft copolymer was increased. The styrene macomer feed ra-tio changed from 5 to 8% then the styrene contents of copolymer increased to ≥55%. It was shown that macromer is more active than vinyl acetate in the process of copolymerization.
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发布时间：2021-03-19
Research Bulletin
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