Pseudo-hexagonal crystallinity in ethene-styrene random copolymers

A comparative X-ray diffraction study on unoriented and oriented samples of ethene based random copolymers with styrene and propene, obtained by singl e site metallocene catalysts is presented. For ethene-styrene copolymers, a s usual for ethene copolymers with comonomers bulkier than propene, an orth orhombic crystal phase is generally observed. However, an oriented pseudo-h exagonal crystalline phase has been obtained in stretched samples, and comp ared with that one known for ethene-propene copolymers.