The Effect of Vulcanized Thermoplastics and SEBS on the Impact Strength of PPT

Abstract

Poly(trimethylene terephthalate) (PTT) is a semi crystalline engineering polymer. It has high physical and mechanical properties like tensile, flexural, stiffness, processabilty and chemical resistance. However, low impact strength limits its versatility. Impact modification of PTT using SEBS and PP-g-EPDM was successfully carried out. The blends of poly(trimethylene terephthalate) (PTT)/styrene-ethylene/butylene-styrene (SEBS) and poly(trimethylene terephthalate) (PTT)/ethylene propylene diene monomer (EPDM) with different composition have been studied. The investigation in the effect of SEBS and PP-g-EPDM on mechanical, thermal, rheological and morphological properties with PTT was done. The tensile strength and flexural strength showed some decrease with increase in concentration of SEBS and PP-g-EPDM in PTT. The impact strength of PTT, however, was found to increase significantly with increasing SEBS and PP-g-EPDM content. The examination of etched surfaces of PTT/SEBS and PTT/PP-g-EPDM using scanning electron microscopy indicated significant improvements in interfacial adhesion. It was found that the addition of SEBS and PP-g-EPDM at higher content reduces the droplet size of the dispersed phase. This is an indication of interfacial saturation of PTT/SEBS and PTT/PP-g-EPDM. Rheological characterization has showed a shear viscosity increased due to the addition of SEBS and PP-g-EPDM in PTT. It means these rheological properties also support for the improvement of impact strength. Thermal properties using differential scanning calorimetric (DSC) results did not show any significant changes.