Studies on the Morphological, Rheological, Electrical, Mechanical and Thermal Properties of the PTT/SCF Composites

Short carbon fiber reinforced poly(trimethylene terephthalate) composites (PTT/SCF) were investigated in their rheology behaviors, phase morphology, electrical, mechanical, and thermal properties by capillary rheometer, scanning electron microscope, universal tester, high insulation resistance meter, Q meter, and thermal gravimetric analyzer. PTT/SCF melt is the dilating fluid at a shear rate below 130 s(-1), while it becomes pseudo-plastic fluid at a shear rate higher than 130 s(-1). Melt apparent viscosity and viscous flow activation energy increase initially, and then decrease as SCF content increases, which have maximum values with 2 wt% SCF. The interaction between SCF and PTT matrix is strong based on the observation from the fracture surface of composites. The tensile strength and rupture strength are all increased obviously with increasing SCF; while the impact strength reaches a maximum value as SCF contents is 5%. With increasing SCF content in matrix, the electrical resistivity is decreased, while the dielectric constant, and the dielectric loss tangent were increased.