Effect of roll temperature on the structure and properties of oriented polypropylene cast film and stretched microporous membrane

Abstract

AbstractThe effect of roll temperature from 60 to 120°C on the crystalline structure and properties of oriented polypropylene (PP) cast films and the stretched microporous membrane was studied. It was found that the long period, the thickness of the crystalline and amorphous phase increase with the increasing roll temperature. And the regularity of the lamellar structure also improves with the increasing roll temperature. In comparison, the lamellae lateral dimension is nearly unchanged at 50 nm. The orientation of the lamellar structure slightly decreases from 0.81 to 0.76 with increasing roll temperature. The increase of the long period and the improvement of the regularity of the lamellar structure lead to the increase of the elastic recovery value of PP cast film. The corresponding microporous membrane also shows a smaller thickness of lamellar clusters, larger pores, better air permeability and better thermal shrinkage resistance. The higher roll temperature is beneficial to the perfection of the lamellar structure, obtaining the higher‐performance microporous membrane.