Crystallization of high ethylene EPDM terpolymers in the stretched state

✍ Scribed by I.W. Bassi; P. Corradini; G. Fagherazzi; A. Valvassori

• Publisher: Elsevier Science
• Year: 1970
• Tongue: English
• Weight: 490 KB
• Volume: 6
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(70)90020-0

✦ Synopsis

Ethylene rich samples of random, ethylene-propylene-diene terpolymers (EPDM) (slightly crosslinked w~th peroxides) crystallize under stretching. The induced crystallinity disappears almost completely in the relaxed state at room temperature. The intensity distribution of the X-ray fibre spectra over the range 8 ~ < 2 0 < 305 has been measured by transmission diffractometric techniques (Cu, Ka). In order to obtain the intensity distribution of an isotropic sample, the intensity distribution of the fibre spectra has been spherically averaged by graphical methods.

All the measurements are normalized to equal optical density and to the same intensity of the primary beam. A method has been derived for the determination of the degree of crystallinity of the stretched samples. The degree of crystallinity of the terpolymers is a function of the degree of stretching and greatly depends on the temperature at which the measurements are made.