Effect of the Molecular Chain Length of Cellulose Trunk Polymer on the Swelling Behavior of Cellulose Graft Copolymer.

Abstract

The partially hydrolyzed graft copolymers of crosslinked polyacrylamide (PAM) on water-soluble hydro-xyethylcelluloses(HECs) with different molecular chain lengths were synthesized by using of the ceric ion in-itiation method in an aqueous medium, and the effect of the molecular chain length of the HEC trunk polymer on the swelling behavior of the graft copolymer (HEC-AM-Hyd) was investigated. The synthesized HEC-AM-Hyds were similar to one another in the proportion of the HEC trunk polymer and the grafted branch polymer and in the crosslinking density and content of carboxyl groups of the partially hydrolyzed PAM branch polymer. The absorbency of HEC-AM-Hyd increased with an increase in the molecular cahin length of the HEC trunk polymer. The HEC-AM-Hyd from the HEC with longer chain length had higher resistibility against the decrease in the absorbency with an increase in the NaCl concentration than that from the HEC with shorter chain length. It is con-sidered that the HEC molecule that has high rigidity and extends largely in water acts effectively in the swelling of HEC-AM-Hyd, and that the superior swelling properties of the HEC-AM-Hyd from the HEC with longer chain length are due to the larger extension of its trunk polymer.