Functionalization of polyolefins and elastomers with an oxazoline compound

The aim of this work was to graft ricinoloxazoline maleinate (OXA) onto pol yethylene (PE), and onto an ethylene propylene copolymer (E/P) and styrene ethylene/butylene styrene copolymer (SEBS), by melt free radical grafting i n a twin-screw midiextruder. A study was made of the effects of the initial monomer and peroxide concentrations and of temperature on the degree of gr afting, on the amount of residual monomer, and on the molecular weight. The initial monomer and peroxide concentrations were 1.5-9.0 wt % and 0.15-0.9 0 wt %, respectively. The grafting yield was found to increase with the ini tial monomer and peroxide concentrations. Grafting yields up to 2.1 wt % fo r PE, 2.3 wt % for E/P and 2.7 wt % for SEES were achieved. The degree of g rafting also varied considerably with the temperature. E/P and SEES decompo sed with low initial monomer and peroxide concentrations, but crosslinked w ith raising the initial concentrations. Polyethylene crosslinked even with low initial concentrations, but with a suitable choice of peroxide grafted polyethylene could be produced with good grafting yields and without gel fo rmation. (C) 1999 John Wiley & Sons, Inc.