In situ Formation of Thermoplastic Composites: Ultem/Vectra

Abstract

This paper is concerned with the development of films of an engineering thermoplastic, polyetherimide (Ultem), reinforced with a thermotropic liquid crystalline polymer (Vectra). In particular the processing conditions for which fibrils of Vectra can be formed are established. The upper processing temperature is established by the point at which the polymers degrade while the lower is that at which G‘ equals G“ of the blend. The morphology, molecular orientation and mechanical properties of the in situ reinforced composite films were investigated as a function of the draw ratio in various drawing zones. With 30 wt% Vectra an increase in the dynamic modulus (both in torsion and tension) of 6–10 times over that of pure Ultem was achieved. In general, the higher the degree of orientation in the liquid crystalline Vectra phase, as determined by wide angle X-ray diffraction (WAXD), the higher the modulus of the composite.