POLYMER CRYSTALLINITY AND ITS EFFECT ON THE NONLINEAR BENDING CREEP RATE FOR A POLYPHENYLENE SULFIDE THERMOPLASTIC COMPOSITE

Recent developments have led to the introduction of advanced thermopla stic composites such as Polyphenylene Sulphide (PPS), which can be use d structurally at higher temperatures. Because of its thermoplastic na ture, it can also be hot worked by bringing the working temperature co nsiderably above the glass transition temperature. However, such annea ling processes also affect its degree of crystallinity, which in turn affect the propel ties of the material. This paper reports on the effe ct of matrix crystallinity on the rate of creep deformation in three p oint bending of some reinforced PPS composites. This work was based on a non-linear approach based on a Power Law creep model creep deformat ion analysis. The effect of annealing on the non-linear creep deformat ion of the PPS composite specimens has been analysed using a Power Law creep model. Results indicate that the creep deformation for both 20 and 40% reinforced samples were relatively similar despite the differe nce in the amount of fibre reinforcement. In contrast, the value of th e creep component decreased exponentially with the % crystallinity, fo r both 20 and 40% reinforced samples.