Deformation mechanism of polyethylene spherulite at elevated temperatures near crystal‐disordering temperature

The effects of temperature upon the orientation behavior of polyethylene crystallites during stretching of the bulk polymer have been measured by means of the x‐ray diffraction technique and interpreted in terms of the deformation mechanism of polyethylene spherulites. With increase of the stretching temperature, especially beyond the crystal‐disordering temperature, the crystal rotation around the crystal a axis probably due to the shearing deformation of crystal lamella along the (001) plane is promoted while the crystal rotation around the crystal b axis due to the untwisting of crystal lamella, is depressed, and the spherulite deformation may be represented by such a fashion as decreasing the number of shells in Wilchinsky's multiple concentric shell structure.