离子液体中纤维素-甲基丙烯酸羟乙酯的均相聚合

在离子液体介质中利用原子转移自由基聚合方法合成了纤维素-甲基丙烯酸羟乙酯的接枝共聚物,采用甲基丙烯酸羟乙酯单体合成纤维素聚合物,并对聚合物进行结构测定与性质分析。通过FTIR、1HNMR和GPC对聚合物结构及相对分子质量(简称分子量,下同)进行分析,研究了不同溶剂对聚合条件、接枝效率的影响,以及在不同溶剂中聚合物的结构、分子量分布、热稳定性及形态有何变化。结果表明,在溶剂N,N-二甲基甲酰胺(DMF)中进行的反应聚合速率及终止速率均高于在丁酮中进行的反应。纤维素接枝甲基丙烯酸羟乙酯聚合物分子量分布约为1.81,该聚合物热稳定性较强;在DMF中呈球状颗粒,平均直径50 nm;在选择性溶剂丙酮中颗粒直径100 nm左右。

Homogeneous Polymerization of Cellulose-2-hydroxyethyl Methacrylate in an Ionic Liquid

With the increasing demand for more efficient utilization of cellulose,the modification of cellulose by graft polymerization provides a significant route to combining the advantages of natural and synthetic macromolecules for a wide range of potential applications.The synthesis of cellulose-graft-PHEMA copolymer via homogeneous atom transfer radical polymerization(ATRP) in the ionic liquid was researched in this article.FTIR,1HNMR and GPC were carried out to analyze the effects of different solvents on the polymerization conditions,grafting efficiency,molecular weight distribution,thermal stability and the changes in shape in different solvents of the copolymer as well.The results indicate that the grafting efficiency increased with the increase of reaction time.The obtained graft copolymer cellulose-graft-PHEMA showed good thermal stability,and the copolymer could aggregate into spherical particles with a diameter of 50 nm in DMF and a diameter of 100 nm in the selective solvent acetone.