had occurred at different screw speeds. The morphology at screw
rpm of 150 was the best than other screw speed. The technical
importance of reaction to make the PP/WF composite needs high
shear stress at PP melt state and suitable residence time. Based
on experimental results, the best screw speed is 150 rpm for screw
configuration C because this is the best condition for reaction to oc-
cur. These results indicate that the properties strongly depend on
the reaction between maleic anhydride groups of compatibilizers
and OH groups on WF particles during processing.
Batch foaming experiments were performed to study the effect
of screw speed on the foamed cell morphology. Fig. 11 shows the
scanning electron micrographs for foamed PP/WF composites that