Journal of Materials Science, Vol.32, No.5, 1319-1324, 1997
Injection-Molding of Self-Reinforcing Polymers and Polymer Blends
In this study it is investigated how to improve the self-reinforcing nature of a liquid crystalline polymer, Vectra, and blends of nylon 6,6 and Vectra processed by injection moulding. Firstly, experiments were conducted on the effect of processing conditions on the mechanical properties of injection moulded Vectra specimens and an optimum injection pressure and melt temperature was specified. Blends of nylon 6,6 with Vectra were then injection moulded under the previously specified optimum processing conditions. During microstructural studies it was observed that the skin contained highly oriented fibrillar domains of Vectra, the density and texture of which changed with blend composition which was varied between 20-30 vol% Vectra. A 25 vol% composition of Vectra displayed the best reinforcing properties and at this composition the fibrils in the skin were arranged into thick bundles. Above a 25 vol% Vectra content the start of fibril coalescence was observed which reduced the self-reinforcing character of the blend.