Temperature Dependence of Modulus, Density, and Crystallinity of Linear Polyethylenes

Abstract

Experiments undertaken to determine the dependence of the shear modulus upon the density and degree of crystallinity of three samples of linear polyethylene over a range of temperatures are described. In most instances, the data show good agreement between crystallinity values calculated from density and from x-ray diffraction measurements. Annealing the polyethylene samples was found to increase both the shear modulus and density. Shear modulus and density appeared to be inversely related to molecular weight for the three polyethylene samples investigated.