Influence of novel screw elements on the reactive extrusion of low density polyethylene grafted with maleic anhydride in co-rotating twin screw extruder

The influences of novel screw elements on grafting reactive extrusion for low-density polyethylene(LDPE) grafted with maleic anhydride(MAH) was investigated in Leistrize30/34 co-rotating twin screw extruder. The specimens were collected from three positions along the extrusion course and the die exit. The grafting degree (GD) of the specimens were determined by titration. In order to compare the influence of different screw elements on the grafting reactive extrusion, the experimental results of conventional screw element and kneading block were introduced. The results showed that different screw elements had remarkable influences on the grafting reactive extrusion and the grafting degree. The novel screw element including the S-type element with high elongation ability and the NI-MPE with back-flow action could improve the grafting degree rapidly. The kneading block with a good mixing performance had a higher grafting degree.