水解聚丙烯酰胺的13C-NMR测定

本文研究了在不同pH条件下P(AM/AA)溶液的¹³C-NMR谱,观察了谱峰的化学位移变化和分裂情况,对比了均聚物PAM和PAA的¹³C-NMR谱,对P(AM/AA)¹³C-NMR谱的各共振峰进行了归属,证实P(AM/AA)共聚物C=O碳峰的分裂只与分子链共聚序列结构相关,并得出了C=O碳分裂峰所对应的三单元序列结构。     

STUDY ON SEQUENCE STRUCTURE OF ACRYLAMIDE-ACRYLATE COPOLYMERS BY ~(13)C-NMR METHOD

Triad sequence distributions in a series of P(AM/AA) with different AA% were calculated from copolymerization reactivity ratio r_1 and r_2 based on first order Markov statistic model, and the calculated data compared with observed ones from ~(13)C-NMR spectra showed good agreement with each other. The sequence distribution in P(AM/AA) obtained under our experimental conditions fits in with first order Markov statistic model. A significant sequence structure difference was observed between P(AM/AA) and alkaline hydrolyzed polyaerylamide, ABA triad (acrylate unit center), AAA and AAB triads (aerylamide unit center) dominated in hydrolyzed ones.