摘要
本文利用丙酮与聚乙烯醇(PVA)链OH侧基之间的反应,制备出缩桐环含量不同(<70mol％)的缩酮化产物(PVKT).通过22.5 MHz ^(13)C-NMR谱对其微观链结构进行表征.研究了反应与PVA空间立构性间的关系.将缩酮环划分为MM-cis、MR-cis及RR-trans三种主要构型,得到相应反应平衡常数K和初始反应速率R,并探讨了它们之间的关系: K_(mm)>>K_(mr)>K_(rr),R_(mm)>R_(mr)>R_(rr)
Through reaction between the hydroxy groups of poly(vinyl alcohol) (PVA) and acetone, various polyvinyl ketal copolymers (PVKT) containing <70% ketal ring-units in the products were obtained. The relationship between tacticity of PVA, rate of ketalization reaction and structural characterization were carried on PVKT by13C-NMR spectroscopy at 22.5 MHz. Ketal rings in partly ketaled PVA were assigned into MM-cis, MR-cis and RR-trans types, and corresponding equilibrium constants Kmm, Kmr, Krr, and rate of ketalization reaction were discussed.
出处
《高分子学报》
SCIE
CAS
CSCD
北大核心
1992年第1期1-8,共8页
Acta Polymerica Sinica
基金
中国科学院结构成分分析开放实验室基金
关键词
聚乙烯醇
立构规整性
缩酮化
NMR
Microtacticity of polymer, 13C-NMR, Reaction with polymer, Polyvinyl- ketal
