双官能度自由基引发剂应用研究的进展

双官能度引发剂在自由基聚合中的应用不断受到重视，本文介绍了常用的双官能度引发剂，并综述了其在制备嵌段共聚物及引发乙烯类单体（如苯乙烯、氯乙烯、丙烯酰胺等）聚合的研究进展。     

水溶性光聚合引发剂研究进展

近几年发展起来的水溶性光聚合引发剂（ＷＳＰ）属自由基引发剂，按结构可分为芳酮类，稠环类烃类，聚硅烷类，酰基膦酸盐等，偶氮类及金属有机配合物类，本文综述了这些光引发剂的结构特性，光化学行为，光引发效率及光反应机理等。     

Free Radical Reaction between 1,6-Dienes and P-Toluenesulfonyl Cyanlde

A sulfonyl-radical-induced addition-cyclization reaction of 1,6-dienes with p-toluenesulfonyl cyanide giving functionalized cyclopentane systems is described.     

Redox polymerization of methyl methacrylate with allyl alcohol 1,2-butoxylate-block-ethoxylate initiated by Ce(IV)/HNO3 redox system

Redox initiated free-radical polymerization of methyl methacrylate (MMA) with allyl alcohol 1,2-butoxylate-block-ethoxylate (AABE) was carried out using cerium(IV) ammonium nitrate/nitric acid (HNO₃) redox system to yield AABE-b-PMMA copolymers. The effects of MMA, AABE, Ce(IV) and HNO₃ concentrations on the polymerization rate and polymer yield were investigated. The effect of temperature on the rate of polymerization and polymer yield was also investigated in the temperature range of 25-70 °C. Copolymers were characterized using GPC, FT-IR, ¹H NMR and viscometry methods.     

TRIFLUOROMETHYLTHIOLATION OF NORBORNENE

Treatment of norbornene with trifluoromethylsulfenyl chloride at ?80°C furnishes, in addition to trifluoromethylthionortricyclane, four isomeric (chloro) (trifluoromethylthio)-norbornanes and bis-(2, 6-trifluoromethylthio)norbornane. The probable mechanism of the formation of the various compounds via free radical intermediates and their mass spectral characterization are described in this communication.     

硫代-Iniferters法活性自由基嵌段共聚合

自由基活性聚合近来发展很快,本文在概述了自由基活性聚合及其最新进展的基础上,对硫代－Ｉｎｉｆｅｒｔｅｒｓ法自由基活性聚合的机理,硫代－Ｉｎｉｆｅｒｔｅｒｓ法大分子引发剂的合成以及这些大分子引发剂在嵌段共聚物的制备等方面进行了综述。     

衣康酸-天冬氨酸-苯乙烯磺酸钠三元共聚物合成及阻垢性能研究

以衣康酸(IA)、天冬氨酸(ASP)及苯乙烯磺酸钠(SSS)为单体,过硫酸铵为引发剂,采用水溶液自由基聚合法合成了IA-ASP-SSS三元共聚物,并对产物结构进行红外表征。探讨单体配比、引发剂用量、聚合温度、反应时间对共聚物阻垢性能的影响,通过正交实验和单因素实验确定最佳合成条件。采用静态阻垢法考察阻垢剂用量、钙离子浓度对阻垢性能的影响。结果表明：共聚单体的物质的量比(nASP:nIA:nSSS)为1:1:0.1、引发剂用量为单体总质量的9%、反应温度85℃且反应时间3h时,合成的IA-ASP-SSS共聚物对碳酸钙、磷酸钙及硫酸钙的阻垢率皆在95%以上,且此共聚物阻垢剂适用于高硬度水环境。     

褐藻酸铜配合物膜催化VAc自由基聚合

以褐藻酸钠膜浸渍在15%CuCl2*2H2O水溶液中48 h的方法,于室温制备了疏水性的褐藻酸铜(Ⅱ)配位聚合物膜,并通过ESR、 UV-Vis、 IR、 XPS和电导率等手段,研究此配位催化剂褐藻酸铜(Ⅱ)配位聚合物膜表面的组成、配位结构和性质,得知1个Cu2+ 是以dsp2杂化空轨道与褐藻酸2个链节单元的2个羧羟基氧及其2个脱质子带负电荷氧的孤对电子发生配位作用,形成低自旋构型的褐藻酸铜(Ⅱ)配位聚合物,中心Cu2+ 的配位数为4,这对于低分子配合物而言,其空间构型一般是正方形,但在褐藻酸铜(Ⅱ)配位聚合物中,由于褐藻酸分子链的缠绕和卷曲,使上述的空间构型被扭曲,甚至有些配位体没有到位,导致该配位聚合物的中心Cu2+ 存在一些空位中心而具有配位催化活性,因此,HSO3-能按配位催化机理产生初级自由基氢,使醋酸乙烯酯(VAc)按自由基加聚反应历程进行聚合,这有别于CuCl2-Na2SO3-H2O氧化还原引发聚合体系。测定VAc在本体系和室温、pH=7条件下聚合的诱导期为90 s,反应时间24 h。聚醋酸乙烯酯(PVAc)得率82%, mw=1.02×106, mn=2.27×105, mw/mn=4.49。     

DMC聚醚的降解研究

研究DMC聚醚 (双金属催化剂的聚环氧丙烷 )的降解现象 .讨论了各种因素对降解的影响 ,以及降解中不饱和度的变化情况 .实验表明 ,DMC聚醚的降解与自由基有关 ,降解在常温下 1 5天后开始发生 ,在抗氧剂存在下受到抑制 .加入抗氧剂 1 0 1 0和 61 8可使聚醚得以稳定储存     

Demethoxycarbonylation and oxidation of 13(S/R)-hydroxy-chlorophyll a to 13-demethoxycarbonyl-13-oxo-chlorophyll a and Mg-purpurin-18 phytyl ester

The conversion of 13²(S/R)-hydroxy-chlorophyll (Chl) a to 13²-demethoxycarbonyl-13²-oxo-Chl a in a yield of 40%, utilizing a simple pyrolysis technique, is described. About 10% of the phytyl ester of Mg-purpurin-18 was formed as a side product. The completely assigned ¹H and ¹³C NMR spectra are presented for 13²-demethoxycarbonyl-13²-oxo-Chl a and a likely mechanism for its formation is proposed. A slight extension of this mechanism also explains the formation of the Mg-purpurin-18 side product. The proposed mechanism has several features comparable with those previously suggested for the allomerization of 13²(R/S)-Chl a. Attempts to apply the same pyrolysis method to prepare 13²-demethoxycarbonyl-13²-oxo-Chl b from 13²(S/R)-hydroxy-Chl b were unsuccessful.