Morphology and Mechanical Properties of Polyamide 6 and Polybutylene Terephthalate Blends Compatibilized with Epoxidized Natural Rubber

Abstract

Blends of polyamide 6 (PA6) and, polybutylene terephthalate (PBT) have been prepared in this work. They were compatibilized using epoxidized natural rubber (ENR-50) by varying amount of ENR-50 i.e., 0, 3 and 5 phr. The effect of blend compositions and compatibilization on the phase morphology and properties of the resulting blends were investigated using a scanning electron microscope, universal testing machine, impact testing machine, and hardness shore durometer. All blends were prepared and shaped by using twin-screw extruder at 260°C and injection molding machine, respectively. The results revealed that the phase morphology of the PA6/PBT blend was incompatible. The separation of PA6 and PBT was observed wherein PBT is dispersed in the form of spherical domains in the PA6 matrix. The mechanical properties exhibit loss in tensile and impact strength. This could be attributed to poor interfacial adhesion between the two polymers. SEM micrographs showed that the addition of ENR-50 improved the compatibility of PA6/PBT blends. With the addition of ENR-50 as a compatibilizer, the uniformity and the maximum reduction of dispersed phase sized were achieved. The water absorption of PA6/PBT blends decreased with an increasing amount of PBT. Additionally, the results indicated that, as the amount of ENR-50 increased, the mechanical properties, including tensile stress at peak, tensile modulus, and izod impact strength were improved.