SUPERMOLECULAR STRUCTURE OF RANDOM COPOLYMERS OF ETHYLENE

The supermolecular structures developed after rapid cryStallizatiOn from the melt of a series of ethylene-1-alkene copolymers has been investigated by small-angle light scattering. Copolymers with butene, hexene, octene, or 4-methylpentene as comonomers were studied over a wide range in molecular weights and copolymer compositions. It was generally found that for given co-unit content the structural order deteriorated with increasing molecular weight. When the molecular weight was fixed, the order deteriorated with increasing co-unit content. However, the level of superstructure organization was very dependent on the length of the side group. The supermolecular structure, for a given molecular weight and composition, was much better developed for the smaller side groups than the larger ones. Possible reasons are suggested for these structural differences.