"LIVING" FREE RADICAL SYNTHESIS OF NOVEL RODCOIL DIBLOCK COPOLYMERS WITH POLYSTYRENE AND MESOGEN-JACKETED LIQUID CRYSTAL POLYMER SEGMENTS*

The synthesis of rod-coil diblock copolymers was achieved for the firsttime by TEMPO-mediated "living" free radical polymerization of styrene and 2,5-bis[(4-methoxyphenyl)oxycarbonyl]styrene(MPCS). The block architecture of the two diblockcopolymers thus prepared, MPCS-b-St(5400/2400) and MPCS-b-St(10800/8700), was con-firmed by GPC, DSC studies and the formation of multimolecular micelles.     

Synthesis of polystyrene latex with amphoteric surfactant and its characterization

An emulsion polymerization of styrene in the presence of an amphoteric surfactant; N,N-dimethyl-n-laurylbetaine (LNB) was carried out at pH 7.0. The polymerization rate and the concentration of the latex particle were proportional to the LNB concentration of 0.6 power. The latex particle sizes became smaller with increasing concentrations of LNB. The molecular weights of polystyrene latices increased with the concentration of LNB. The zeta-potentials of latex particles were significantly dependent on the pH, and showed the existence of an isoelectric point.     

Asymmetric zirconocene precursors for catalysis of propylene polymerization

Racemic isopropylidene (1-η⁵-cyclopentadienyl)(1-η⁵-indenyl) dichlorozirconium and the 3-methylindenyl derivative have been synthesized and characterized. These precursors activated with methylaluminoxane produce poly(propylene) with hemiisotactic microstructures. © 1994 John Wiley & Sons, Inc.     

配位聚合载体化催化剂ESR研究进展

本文概述了配位聚合载体化催化剂的ESR研究进展,介绍了载体研究、活性中心研究及计算机模拟技术研究方面的发展概况.     

Tree-gel and loop-gel conversions in nonlinear polymerization

Ａｓｉｓｗｅｌｌｋｎｏｗｎ,ｔｈｅｔｈｅｏｒｙｆｏｒｎｏｎｌｉｎｅａｒｐｏｌｙｍｅｒｉｚａｔｉｏｎｓｗａｓｉｎｉｔｉａｔｅｄｂｙＦｌｏｒｙａｎｄＳｔｏｃｋｍａｙｅｒ[1—3].ＭｉｌｌｅｒａｎｄＭａｃｏｓｋｏ[4—6]ｐｒｏｐｏｓｅｄａｒｅｃｕｒｓｉｖｅｍｅｔｈｏｄｆｏｒｄｅａｌｉｎｇｗｉｔｈｔｈｅｐｒｏｂｌｅｍｏｆｔｈｅｐｏｓｔｇｅｌｐｒｏｐｅｒｔｉｅｓｏｆｔｈｅｎｅｔｗｏｒｋｆｏｒｍｉｎｇｐｏｌｙｍｅｒｉｚａｔｉｏｎ.Ｓｔｅｐｔｏ[7]ｉｎｖｅｓｔｉｇａｔｅｄｔｈｅｇｅｌｇｅｌｒｅａｃｔｉｏｎｏｆＲＡｆｔ…     

甲基丙烯酸甲酯悬浮聚合实验教学的改进

选用氢氧化镁为分散剂,甲基丙烯酸甲酯(MMA)为单体,进行悬浮聚合反应,研究了分散剂用量、引发剂用量、水和单体比、搅拌速度、反应温度及反应时间对聚合物珠粒大小、均匀程度和产率的影响。结果表明:与目前高分子实验教材普遍选用的以聚乙烯醇(PVA)为分散剂的悬浮聚合反应相比,以氢氧化镁为分散剂,具有操作简单、聚合时间短、体系稳定性高等优点,可代替原有的悬浮聚合反应实验,作为高分子化学实验的教学课程内容。     

原子转移自由基聚合原位合成温敏性微球

以过硫酸钾为引发剂、丙酮-水[V(丙酮)∶V(水)＝4∶6]的混合溶剂为反应介质, 在少量二乙烯苯存在的条件下使苯乙烯(St)和对氯甲基苯乙烯(CMSt)进行无皂乳液共聚反应, 得到了粒径大小均匀的交联型聚苯乙烯(PSt)微球, 由X射线光电子能谱对表面组分测定发现: CMSt上的氯原子在聚合过程中富集于交联微球的表面. 以此交联型PSt微球为原子转移自由基聚合(ATRP)的引发剂, 在22 ℃下引发N-异丙基丙烯酰胺(NIPAAm)进行原位ATRP反应, 得到了表面原子转移自由基聚合接枝的交联聚苯乙烯(PNIPAAm-g-PSt)温敏性微球. 借助傅立叶变换红外光谱、差示扫描量热仪、扫描电子显微镜及激光光散射仪等对PNIPAAm-g-PSt的结构、相转变温度、形态及不同温度下的粒径变化进行了测定, 结果表明NIPAAm单体成功地原位ATRP接枝在交联PSt微球的表面, 接枝微球的球形更规整, 在水中的相转变温度约为32 ℃, 具有明显的温度敏感性.     

Production of submicron-size monodisperse polymer particles having aldehyde groups by seeded aldol condensation polymerization

Submicron-size monodisperse polystyrene/polyglutaraldehyde composite particles having aldehyde groups at the surfaces were produced by seeded aldol condensation polymerization of glutaraldehyde in the presence of polystyrene particles prepared by emulsifier-free emulsion polymerization. This technique is expected to be useful for the production of size-controlled polymer particles having aldehyde groups.Part CXXXVI of the series Studies on Suspension and Emulsion     

聚合物-Ni(II)膜电极的研究

Ni(Ⅱ)离子可与聚8羟基喹啉、聚邻氨基酚、聚邻苯二胺和聚苯胺络合。聚合物-Ni(Ⅱ)膜电极的循环伏安图有明显的氧化还原蜂, 和彼此相似的电化学特性。聚8羟基喹啉膜(聚邻氨基酚, 聚邻苯二胺)可用以交换Ni(Ⅱ)与H~+离子和分离Ni(Ⅱ)、Co(Ⅱ)和Fe(Ⅱ)离子。