Synthesis of polyethene-graft-polystyrene copolymers from linear polyethene-containing cyclopropane rings

An efficient procedure to produce polyethene-graft-polystyrene (E-C3-graft-PS) copolymers by simple thermal treatment at 200 °C of polyethene (PE)-contg. cyclopropane ring units (E-C3) in the presence of a high excess of styrene is reported. The high treatment temp. likely induces the breaking of the constrained cyclopropane rings, leading to the formation of radicals on the PE chains. The presence of styrene during the thermal treatment allows the formation of side polymer chains on the starting materials and, consequently, of graft copolymers. The graft copolymers that were obtained are efficient compatibilizers for polymer blends as was detd. from scanning electron micrographs, which were used to examine the bulk morphologies of two blends: one composed of 50/50 PE and polystyrene (PS), and the other of 49/49/2 PE, PS and E-C3-graft-PS