GRAFTING OF ACRYLAMIDE ONTO SURFACE OF COPOLYMERS CONTAINING P-TOLYLCARBAMOYL PENDANT GROUP INITIATED WITH CERIC SALT

Two copolymers containing p-tolylcarbamoyl pendant group poly (MAMT-co-VAc) and poly(MAMT-co-MA) were synthesized f and the graft copolymerization of AAM onto these two func-tional copolymers films initiated with ceric salt were carried out in aqueous solution for variousperiods at 30℃. The formation of graft copolymer was verified by water absorption, ESCA andSEM photographs. Based on the results of the study of the initiation mechanism of model com-pounds and ceric salt systems, the reaction mechanism of the graft copolymerization initiated withceric salt was proposed.     

四氢呋喃开环聚合的研究——Ⅱ.溴丙烯与高氯酸银引发体系

<正> 对四氢呋喃(THF)活性聚合的研究已有不少报导.近来,活泼有机卤化物与银盐组成的引发体系引起人们的重视,这不仅因为活泼卤化物易于制备;而且如以含有活泼卤原子的高聚物与银盐为引发体系可直接制得嵌段或接枝共聚物.对这类大分子链引发体系的特性常可通过以小分子有机卤化物作为模型进行研究. 我们对溴丙烯-高氯酸银引发体系进行了研究.1977年Lee等人曾用这一类引发体系使THF聚合,达到了平衡收率而认为在室温即可成活性聚合.为验证这一结论是否     

甲基丙烯酸磺酸基己酯钠盐的共聚合、聚合及其均聚物的抗凝血性能

研究了甲基丙烯酸6-磺酸基己酯钠盐与甲基丙烯酸甲酯、甲基丙烯酸β-羟乙酯及甲基丙烯酸正己酯的共聚合,并测定了它在水及二甲亚砜中的聚合速度关系式。聚甲基丙烯酸6-磺酸基己酯钠盐的抗凝血性能在一定分子量范围内相差不多。     

丙烯酸酯在苯肼存在下的氧化和聚合研究

苯肼存在下丙烯酸酯的吸氧和氧化速度迅速增加,苯肼浓度约0.1—1.0％范围时,并发生聚合。 不同结构丙烯酸酯在苯肼存在下的吸氧与聚合的次序为:甲基丙烯酸 2-甲氧基乙酯>甲基丙烯酸羟基丙酯>甲基丙烯酸甲酯。我们认为苯肼存在下丙烯酸酯的氧化机构可能是苯肼结合丙烯酸酯醚键或双键α位碳原子上的氢,形成负碳离子或疏松离子对,从而在氧作用下生成过氧化合物。     

STUDIES ON THE OXIDATION AND GRAFT COPOLYMERIZATION OF POLY(ETHER-URETHANE)

A new method of graft copolymerization of acrylamide (AAM) on poly(ether-urethane) (PEU) which was prepared from poly(tetramethylene ether) glycol (PTMG), 4,4'-diphenylmethane diisocyanate (MDI) and ethylene diamine or butanediol extender was investigated. Hydroperoxide group was first introduced onto the surface of PEU through photo-oxidation in the presence of hydrogen peroxide, then it was reacted with ferrous ion or N,N-dimethyl toluidine (DMT) to initiate AAM graft copolymerization on PEU surface. The graft reaction could be carried out effectively at low temperature. The formation of graft copolymer has been verified by its water absorption % and the scanning electron microscopy photographs. Some model compounds of PEU soft segment and hard segment were synthesized in order to clarify the site of graft reaction. The results of oxida-tion and graft copolymerization of model compounds showed that this graft copolymerization possesses higher selectivity, and it takes place predominately at the polyether segments, because the ether linkage in soft segment is very sensitive to oxidation and can form hydroperoxide easily. Thus, the grafting site appears to be at α-carbon of the ether linkage.     

受阻胺对甲基丙烯酸甲酯聚合的影响

本文研究了受阻胺TMP、TMPM、TUV-770对MMA、St本体聚合的影响。无论用BPO或AlBN引发MMA聚合时,TMPM或TUV-770都能延长诱导期,但对R_p的影响较小,而TMP能使R_p略增。测定了聚合反应的表观活化能和动力学方程。     

过硫酸盐和脂肪环胺体系引发机理的ESR研究

用ESR方法研究了过硫酸盐和脂肪环胺吗啉,哌啶及其N-烷基取代衍生物体系引发反应的初级自由基,结合端基分析,证实了这类脂肪环胺与过硫酸盐反应产生的初级自由基都能引发烯类单体聚合。当所用的是脂环仲胺时,其初级自由基为氮中心自由基;用脂环叔胺时,初级自由基是N-烷基的α-碳中心自由基。     

PHOTOINDUCED CHARGE TRANSFER POLYMERIZATION OF STYRENE INITIATED BY ELECTRON ACCEPTOR

Photoinduced charge transfer polymerization of styrene (St) with electron acceptor asinitiator was investigated. In case of fumaronitrile (FN) or maleic anhydride (MA) asinitiator the polymerization takes place regularly, whereas the tetrachloro-1, 4-benzenequinone (TCQ), 2, 3-dichloro-5, 6-dicyano-1, 4-benzenequinone (DDQ). ortetracyano ethylene (TCNE) as initiator the polymerization proceeds reluctantly only afterthe photoaddition reaction. A mechanism was proposed that free radicals would be formedfollowing the charge and proton transfer in the exciplex formed between St and electronacceptors.     

THE EFFECTS OF N-2-HYDROXYETHYL-N-METHYL-p-TOLUIDINE ON METHYL METHACRYLATE RADICAL POLYMERI-ZATION AND ACRYLONITRILE PHOTOINDUCED POLYMERIZATION

The effects of N-2-hydroxyethyl-N-methyl-p-toluidine (HMT) on MMA polymerization using organic peroxide as an initiator and on AN photoinduced polymerization have been investigated respectively. The kinetics of polymerization and the overall activation energy of polymerization were determined. Based on kinetics study and the end group analysis of the polymer obtained by UV spectrum method, the initiation mechanism is proposed.     

甲基丙烯酸二缩三乙二醇双酯的氧化及其厌氧胶吸氧的研究

甲基丙烯酸缩乙二醇双酯,作为一种双官能基单体,是配制厌氧胶的主要组分,本文研究了室温和70±2℃下甲基丙烯酸二缩三乙二醇双酯(双酯)的氧化,以及DMT、CHPO、糖精、对苯二酚、草酸、铜离子等对双酯氧化的影响,发现DMT、铜离子明显加速双酯氧化,而对苯二酚、草酸抑制双酮氧化,与DMT共存时,糖精对氧化亦起加速作用。 此外,本文研究了厌氧胶与吸氧的关系,发现厌氧胶是一个不断吸氧的体系,厌氧胶中各组分对双酯吸氧与稳定性的影响与它们对双酯氧化的影响基本上是平行的,即DMT与铜离子促进双酯吸氧并降低稳定性,草酸抑制吸氧并增加稳定性,CHPO和糖精对双酯吸氧和稳定性影响比较小,但有DMT存在时,糖精则明显起加速作用。