A new process to prepare polyolefin-graft-vinyl polymers was developed. Vinyl monomers, a peroxide monomer which has O-O bonds inside (HE.PO, CH2=C(CH3)COOC2H4OC(O)-O-O-t-Bu), and an organic initiator were impregnated in polyoleiin pellets which were suspended in water. The vinyl monomers were polymerized in the polyolefin pellets (impregnation polymerization) and the resulting polymers were thermally mixed in an extruder in which reactive processing (grafting onto polyolefins) took place. Conversion of the impregnation polymerization was almost 100% in case of polyolefin/styrene/HE - PO in 70/30/0.9 parts ratio. Grafting efficiencies of poly(St-srai-HE - PO) prepared in 30/0.9 parts ratio onto lower density polyethylene (LDPE), polypropylene (PP), ethylene-ethylacrylate copolymers (EEA), ethylene-vinylacetate copolymers (EVA), and ethylene-propylene-diene copolymers (EPDM) (70 part) were 33, 59, 50, 46, and 56%, respectively. The resulting graft copolymers are useful as polymer modifiers and compatibility improvers. The graft copolymers obtained here had greater elongation at break than the corresponding straight blend. Vinyl polymer segments of graft copolymers micro-dispersed in the polymer matrix and showed strong adhesion at interface. © 1990, The Society of Polymer Science, Japan. All rights reserved.
