4. Cellulosic Graft Copolymers

Graft copolymerization of cellulosics has been widely investigated to modify the polymer molecules and alter the surface properties of the bulk materials. While practical advantages for the graft copolymerization were found in the surface modifications, basic and systematic studies on the cellulosic molecular grafting were not conducted very well throughout the past century. One reason for the lesser amount of systematization work was the difficulty of elaborate synthesis involved in the controlled polymerization and product isolation and characterization for obtaining the target copolymers. However, since 2000, serious efforts have been made to tackle the formulation of the structure–property relationships at molecular and supramolecular levels and the material functionalization based on those elucidations. In this chapter, the authors review the progress in copolymerization and product isolation, molecular characterization, general thermal transition scheme, thermal treatment effect on the supramolecular structure development, molecular dynamics, and orientation characteristics, mainly for cellulose ester-graft-aliphatic polyesters. Examples of material functionalization include controlled biodegradation and modulation of optical birefringence for molded films of the graft copolymers.