On the improvement of the processability of UHMW-HDPE by adding a liquid crystalline polymer and a fluoroelastomer

Ultra-high molecular weight polyethylene possesses many interesting propert ies but a very bad processability. This material is not usually processed i n conventional devices but only by compression moulding and RAM extrusion. Low molecular weight polyethylene can be used to improve the processability . In this work small amounts of a fluoroelastomer and of a liquid crystalli ne polymer have been used as processing aids to improve the extrudability o f this polymer. In fact, the die pressure decreases whereas the output flow rate slightly increases with increasing concentration of the processing ai ds. Solution viscosity data shows that reduction of the mechanical stress d uring extrusion decreases the degradation of the polyethylene.