Structural study of cellulose-acrylamide copolymers

Abstract

The sedimentation S, progressive diffusion D, intrinsic viscosity [η], and the flow birefringence [n] in Cadoxene solutions of cellulose (C) and its copolymers with acrylamide (AA) were investigated. The copolymers produced by grafting AA on to C in the presence of cobalt salts are graft copolymers containing 8–13 grafts of poly-AA molecules having M = 4 × 10 4−5 × 10 5. The molecular weights of the grafts depend on the ratio of Co (III) ions to monomer concentration over a wide range of copolymer compositions. The molecular weight of the fundamental material in the copolymer remains fairly large ( M ∼ 2 × 10 5) despite the strong oxidizing effect of the cobalt. The following correlations were found for the copolymers: [ η] = 1·5 × 10 −3 M 0·5, S 0 = 1·5 × 10 −16 M 0·5, D 0 = 3·5 × 10 −5 M −0·5. The C-AA copolymers have a narrow MWD and small compositional heterogeneity of macromolecular structure of the native cellulose.