Roll-drawing and die-drawing of toughened poly(ethylene terephthalate). Part 1. Structure and mechanical characterization

In this work, two solid-state forming processes, namely roll-drawing and die-drawing, were evaluated for inducing high levels of orientation in toughened semicrystalline poly(ethylene terephthalate) (PET), modified with a metallocene ethylene-octene copolymer. In order to study the role of adhesion at the particle/matrix interface, the elastomer was grafted with glycidyl methacrylate (GMA). The GMA functional groups, which can graft to PET to form a copolymer, induced a reduction in the size of the elastomeric phase. The oriented toughened sheets from roll-drawing and die-drawing processes were characterized in terms of processing conditions (process and draw ratio), interfacial modification (GMA grafting), morphology (particle size and shape) and tensile mechanical properties (modulus, yield stress and toughness).