Influence of Filling Ratio on the Grafting Ratio of PE-LD-g-MAH Prepared by Reactive Extrusion Using Different Screw Configurations

The filling ratio and the grafting of MAH onto PE-LD during an extrusion using co-rotating twin screws with different configurations have been investigated,and the effect of filling ratio on the grafting degree has been discussed.The grafting degree of the specimens that was taken from upstream and downstream reaction zone was determined by titration.The filling ratios in the main reactive zones were estimated by clam barrel for different screw configurations.It showed that the filling ratio and the location of the melting endpoint along the screw had major influences on the grafting degree.The nearer the location of the melting endpoint to the feeding port,the earlier the grafting reaction started,the higher the grafting degree obtained in upstream zones.The higher the filling ratio,the greater the grafting degree obtained at the same sampling point.