聚乙烯醇的固相加成反应酰胺化改性

A Solid Phase Amidation Modification of Polyvinyl Alcohol

基于Michael加成反应,通过固相反应将酰胺基引入聚乙烯醇(PVA),制备了酰胺化改性PVA。用核磁共振氢谱(1H-NMR)、动态机械热分析(DMTA)、红外光谱(FT-IR)、差示量热扫描(DSC)分析了改性PVA的结构。结果表明丙烯酰胺(AM)成功接枝到了PVA分子链上,且改性PVA的结晶度低于PVA原样,并随AM用量的增大,样品结晶度先减小后增大,其玻璃化转变温度(Tg)也呈先增大后减小的趋势。黏度测试、结皮测试和溶解测试结果表明,酰胺化改性有利于产品静态黏度的降低,可显著改善样品的结皮性,提高溶解速度。

In this paper,a solid phase method was used to introduce amide group into PVA chain based on Michael addition reaction.The structure of acrylamide modified PVA was investigated by FT-IR,1H-NMR,DMTA,DSC.The results indicate that acrylamide has been successfully grafted to the PVA chain.For a fixed graft yield,the crystallinity and Tg of polyvinyl alcohol reduce firstly and increase afterward with the increase of acrylamide graft yield.And the properties of amidated PVA were investigated by viscosity,surface crusting and dissolving.The results of the tests show that amidated PVA has low solution viscosity.Amidation modification can notably increase the dissolution rate of PVA,and decrease the surface crusting time of PVA water solution.