低温乳液聚合制备超高分子量聚乙烯醇.pdf

塑料丁业
第44卷第5期
CHINA PLASTICS INDUSTRY
2016年5月
成τ低温乳液聚合制备超高分子量聚乙烯醇
程
寇书培,李静静,汪映寒
(四川大学高分子材料工程国家重点实验室,高分子科学与工程学院,四川成都610065)
摘要:采用一种新型氧化还原引发体系过硫酸钾(KPS)/N,N-二.甲基乙醇胺(DMEA),通过低温乳液聚合制备
了超高分子量的聚醋酸乙烯酯(PAc),醇解得超高分子量的聚乙烯醇(PVA)。研究了不同引发剂质量分数、温度
和乳化剂浓度对聚合反应的影响。结果表明,实验结果与一般自由基聚合规律一致,但由于醋酸乙烯酯(VAe)白由
基本身活性很高,易发生链转移,乳化剂对VAc聚合有一定的缓聚作用。KPS/ DMEA引发体系相比常用的KPS/
NAHSO3具有更高的引发反应活性。反应最佳条件如下:反应温度2℃,引发剂质量分数为0.4%,乳化剂质量分数为
0.5%,得到PVAc的黏均聚合度为28940,PVA的黏均聚合度为9077,支化度为2.19。
关键词:低温乳液聚合;聚乙烯醇;N,N-二甲基乙醇胺;超高分子量
doi:10.3969/j.issn.1005-5770.2016.05.005
中图分类号:TQ325.9
文献标识码;A
文章编号:1005-5770(2016)05-0018-04
Preparation of Ultra-high Molecular Weight Polyvinyl Alcohol by
Low empreture Emulsion Polymerization
KOU Shu-pei, II Jing-jing, WANG Ying-han
(State Key Laboratory of Polymer Materials Engineering, College of Polymer Science and Engineering
Sichuan University, Chengdu 610065, China)
Abstract: The ultra-high molecular weight polyvinyl acetate (PVAC) was prepared via low tempreture
emulsion polymerization, using a new redox initiator system of potassium persulfate(KPS)/N, N-dimethyl
ethanolamine (DMEA). Then ultra-high molecular weight polyvinyl alcohol (PVA) was prepared by the
alcoholysis of PVAC. The influence of the initiator concentration, temperature, emulsifier concentration on
the polymerization was investigated. The results show that the experimental results corresponded well to the
theoretically predicted tendencies. The emulsifier SDS/OP-10 acts as the inhibitor due to the high activity of
vinyl acetate radical. Comparing with the conventional initiator system of KPS/NAHSO KPS/DMEA has a
higher initiating reactivity. The optimal polymerization conditions are as follows: the initiator concentration is
0. 4w1%, the emulsifier concentration is 0. 5wt%, the reaction temperature is 2 C, The degree of
polymerization of PVAC and PVA was 28 940 and 9 077, respectively, and the degree of branching is 2. 19
Keywords Low Temperature Polymerization Polyvinyl Alcohol N, N-dimethyl Ethanolamine
Ultra-high Molecular Weight
聚乙烯醇(PVA)因其特殊的结构,而具有高式制备。本体聚合由于黏度高,散热困难而难以工业
强度、高模量、良好粘接性、耐溶剂性、耐酸碱性、化2。溶液聚合由于自由基容易向溶剂链转移而难
耐磨性、气体阻隔性能以及生物相容性,被广泛应用以得到超高分子量的聚合物。目前国内外对VAc
于纤维、薄膜、食品包装袋、隔离膜、药物传输等方悬浮聚合和乳液聚合进行了大量研究?。研究表明
面。尤其在高强高模纤维方面,要求PVA具有高降低温度,可有效降低自由基链转移而制得超高分子
的相对分子质量(以下简称高分子量)。聚乙酸乙烯量的PVAc及PVA。紫外光引发、辐照引发、高活性
酯(PVAc)是PVA的前驱体,可以由醋酸乙烯酯引发剂引发等方式均可以降低聚合温度,但是紫外光
(VAe)单体通过本体、溶液、悬浮、乳液聚合等方引发和辐照引发?,由于设备复杂,生产成本
作者简介:寇书培,男,1990年生,硕土研究生,主要从事高性能聚乙烯醇的合成研究。kshup46994@q.com