Functionalization of polyolefins in the melt through reaction with molecules and macromolecules

Functionalization of polyolefins with diethyl maleate (DEM) is investigated to improve compatibility with other polar polymers through reactive blending. Functionalization experiments were carried out in the melt with peroxide initiator and mechanical mixers as reactors. The effect of feed composition, reactor type and duration on the functionalization degree, degradation and crosslinking reactions were examined starting with different ethylene polymers. In this way conditions were identified allowing modulation of functionalization with 2-(diethyl succinate) groups from 0.2 to 2.5% mole, and keep to negligible level undesired by-reactions such as crosslinking and degradation. The chemical reactivity of these functional groups to form interchain covalent bonds was investigated in case of the reaction of the ester groups on the polyolefin backbone with the amino end group of linear polyamides (in particular PA 6). Evidences of the formation of grafted polymer on the basis of fractionation of the resulting mixture, instrumental analysis and morphological characterization are presented.