聚乙烯-超支化聚缩水甘油醚两嵌段共聚物的合成及性能表征

Polyethylene-b-Hyperbranched Polyglycerol Diblock Copolymers:Synthesis and Property Characterizations

介绍一种由线性聚乙烯(PE)嵌段和超支化聚缩水甘油醚(hbPG)嵌段组成的"线性-超支化"两嵌段共聚物的合成和性能表征。通过烯烃配位聚合方法制备出仅在主链末端带有一个羟基的线性聚乙烯(PE-OH),以此作为大分子引发剂引发缩水甘油开环多支化聚合,得到羟基末端嵌段共聚物(PE-b-hbPG-OH)。为便于表征,将共聚物超支化部分末端羟基酰化改性(PE-b-hbPG-Bz),改善嵌段共聚物的溶解性。凝胶渗透色谱GPC测试结果显示单峰且无拖尾,表明所得聚合物的结构均一;傅里叶转换红外光谱FTIR和核磁共振NMR测试结果共同证实嵌段共聚物的结构;热重分析TGA结果可确定2个嵌段的质量比;差示扫描量热法DSC测试结果则表明超支化部分对线性聚乙烯部分的熔融、结晶性质影响很小。

This paper reports the synthesis and property characterizations of linear-b-hyperbranched copolymers with linear polyethylene block and hyperbranched polyglycerol segment.The linear PE with only one hydroxy at the end of its backbone（PE-OH）was synthesized through coordination polymerization,and used as macroinitiator to initiate the ring-opening multibranching polymerization of glycidol to prepare objective products（PE-b-hbPG-OH）.Modification of the plentiful hydroxy of PE-b-hbPG-OH by benzoyl chloride was carried out to improve its solubility（PE-bhbPG-Bz）in order to facilitate characterizations.GPC curves had only one peak and no trailings which showed uniform structure of the polymers.FTIR and NMR results confirmed the chemical structure of the block copolymers.TGA curves showed two weightlessness stages corresponding to two blocks′mass ratio.DSC results showed a weak affection of hbPG on PE′s fusion and crystallization properties.