Polymer Solid-Phase Grafting at Temperature Higher than the Polymer Melting Point through Selective Heating

Abstract

A new polymer grafting method, which is a solid-phase reaction but its grafting temperature is higher than the polymer melt point, is reported in this paper. This solid grafting reaction at high temperature can be achieved by using microwave which selectively heats the substance that can absorb microwave. Maleic acid-grafted polypropylene (PP-g-MA) was prepared by this new method. It is well known that polypropylene (PP) is transparent to microwave while maleic anhydride (MAH) can be heated by microwave. Under microwave irradiation, MAH dispersed in the micropores of PP spherical powder can absorb microwave to generate high temperature and cause PP nearby and MAH itself to generate free radicals. MAH-grafted PP (PP-g-MAH) can be prepared without using an initiator. The new method has many advantages that traditional methods do not have. For example, the prepared graft polymer has no initiator and MAH residue and thus is odorless; the prepared graft polymer also has excellent mechanical properties because ...