GRAFT-COPOLYMERS OF POLYSTYRENE AND POLYISOPRENE PREPARED BY COMPLEXATION OF FUNCTIONALIZED HOMOPOLYMERS

Physical graft copolymers were prepared from intermolecular interactions between functionalized polystyrene and polyisoprene. The polystyrene was modified with up to 8 mol % sulfonic acid or zinc sulfonate groups, and the polyisoprene was capped at one end of the chain with a dimethylamino group. Hydrogen bonding or transition-metal complexation between the functional groups yielded a graft copolymer molecular architecture that led to stabilization of the scale of phase separation in blends of the two polymers. Intermolecular aggregation also persisted in solution in relatively nonpolar solvents, which also perturbed the solution viscosity.