Modification of Cellulose by Using Atom Transfer Radical Polymerization and Ring-Opening Polymerization

Abstract

The cellulose chloroacetate (Cell-ClAc) with a degree of substitution (DS) value of about 2.1 was synthesized through acylation reaction of microcrystalline cellulose in a homogeneous solution of dimethylacetamide/lithium chloride (DMAc/LiCl), and pyridine as the acid acceptor. Atom transfer radical polymerizations (ATRP) of 3-ethyl-3-methacryloyloxymethyloxetane (EMO) and methyl methacrylate (MMA) were carried out by using Cell-ClAc as the initiator. Furthermore, the second ATRP reactions of MMA and EMO by using the products of Cell-PEMO and Cell-PMMA as initiators were performed, respectively. It was based on the consideration of that the terminal halogens of Cell-PEMO or Cell-PMMA possess activity even after a long time period and could be used as initiator for another ATRP reaction. Different reactions including the activators generated by electron transfer (AGET) ATRP of EMO or MMA and the Ring-Opening Polymerization (ROP) of aliphatic cyclic ester (CE) (ε-caprolactone (CL), or L-Lactide (LLA)) proceed in a same reaction system simultaneously by using the same initiator of Cell-ClAc or Cell-PEMO or Cell-PMMA were also carried out. For analyses of products, the measurements of FT-IR, DSC, TG-DTA, WAXD were performed, and a Polarizing Microscope (POM) was also used for crystal observation of the products. All the measurement results proved the proceeding of the reactions.