Disorder-order transition in microporous oriented polyethylene films

Spatial correlations on the surface of microporous polyethylene films obtained by extrusion of the polymer melt with the subsequent stages of annealing, uniaxial extension, and thermal fixation have been studied using scanning electron microscopy. It has been shown that, as the degree of orientation of the melt increases, the formation of the periodic superlattice of oriented lamellae occurs in the films as a result of the disorder-order transition. This transition is preceded by the formation of two mutually complementary percolation clusters, which reflect the pores and the solid phase of the polymer.