Changes in Fold Structure with Annealing in Polyethylene

Abstract

During the annealing of quenched linear polyethylene, the ratio of the absorbance of the 1304 cm−1 band to the absorbance of the 1350 cm−1 band decreases toward the value found in single crystals and has the wrong annealing temperature dependence. Since this process takes place too slowly to be a recrystallization from the melt, this change must reflect a transformation of loose‐loop type folds to the more regular type as found in single crystals. Slowly cooled samples have the same ratios as single crystals and do not change upon annealing.