甲基丙烯酸甲酯-丙烯酸丁酯共聚物微观结构研究
MICROSTRUCTURE STUDY of METHYL METHACRYLATE BUTYL ACRYLATE COPOLYMER BY 13 C NMR SPECTROSCOPY
Abstract
用13CnMr研究了由基团转移共聚得到的甲基丙烯酸甲酯丙烯酸丁酯共聚物的微观结构,共聚物中单体链节的三元组含量从季碳和羰碳的共振信号测得,实验测得的三元组分数与通过竞聚率和单体组成比按末端基效应模式的计算值相符.丙烯酸丁酯由于具有大得多的竞聚率值而呈现较强的均聚倾向. A detailed study of the microstructure of methyl methacrylate (MMA) and butyl acrylate (BA) copolymer prepared by group transFer polymerization (GTP) was carried out by using 13 C NMR spectroscopy.Methyl methacrylate and butyl acrylate centred triad molar Fraction were determined From the quaternary carbon and carbonyl group resonance signale.The experimental sequence concentrations were in agreement with the values calculated From the terminal copolymerization model and bernoullian statistics.A greater block tendency of BA monomers may be noticed in both experimental and calculated distribution, which is due to the large diFFerence between the reactivity ratios of MMA and BA in group transFer copolymerization.