聚醚氨酯的氧化及其接枝共聚合的研究

本文研究了在聚醚氨酯表面上进行接枝共聚合的新方法。首先在聚醚氨酯薄膜上通过过氧化氢光氧化引入过氧化氢基,然后在还原剂亚铁盐或N,N-二甲基对甲苯胺的作用下引发丙烯酰胺接枝共聚合,反应具有低温快速的特点。产物经吸水性实验及扫描电子显微镜观察均证实了是一接枝共聚物。通过模型化合物的研究证明,接枝反应具有较高的选择性,接枝共聚占优势地发生在聚醚软段上,接枝地点很可能就在醚键旁的α-碳原子上。

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

A new method of graft copolymerization of acrylamide (AAM) on poly(etherure-thane) (PEU) which was prepared from poly(oxytetramethylene) glycol (PTMG), 4,4'-diphenylmethane diisocyanate (MDI) and ethylene diamine (E) or butanediol (B) extender was investigated. Hydroperoxide group was first introduced onto the surface of poly(ether-urethane) 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 o,ut at low temperature with high speed. The grafted PEU film became opaque and its water absorption increased. 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 graft reaction mechanism. The results of oxidation and graft copolymerization of model compounds showed that this graft copolymerization possesses higher selectivity, and it takes place predominately in polyether segment because the ether linkage in soft segment is very sensitive to oxidation and can form hydro-peroxide easily. Thus, the grafting site appears to be at o-carbon of the ether linkage.