Study on structures and properties of melt spun and cold drawn metallocene poly(ethylene–co–1–octene)

A basic study on the structures and properties of melt spun and drawn metallocene catalysed ethylene–octene copolymer with different octene contents is described. All polymers were melt spun under different draw down ratios (DDRs) and temperatures. The crystal structures formed in the spinline were characterised by wide angle X-ray diffraction. An orthorhombic unit cell was found in all polymers, but a hexagonal form was also found for the polymer with the highest octene level. Orientation was determined by birefringence and orientation factors for a, b and c axes were determined. Subsequent cold drawing was performed on as spun filaments with different DDRs. Several reflection peaks from monoclinic unit cell were found for the polyethylene without octene. For those with higher octene levels, the reflection peaks were faint and only a bump was observed. Necking and orientation were studied on as spun filaments with different DDRs during cold drawing.