Structure and deformation of polyethylene hard elastic fibers

Stress-strain and relaxation tests were performed in air between—196°C and +80°C, and in methanol and silicone oil at room temperature on linear polyethylene hard elastic fibers. Transmission electron microscope observations of similarly deformed specimens indicated that straining resulted in fibrils connecting separated lamellae. A new model was developed in order to rectify deficiencies which were exposed in existing models by our experimental results. The model attributes the stress for extension to the pulling of fibrils from lamellae and the retractive forces resulting in the particular elastic properties to surface energy and entropy effects in the fibrils.