Morphology- properties relationship of post-consumer pet and PP blends

Abstract

Blending of recycled polyethylene terephthalate (RPET) with polypropylene (PP) was studied in the present work in attempts to obtain a new material with enhanced properties, respect to the starting materials. The success of the project depends mainly on the possibility to make products from RPETIPP blend. Therefore, fundamental information in terms of blend composition, compatibilization, molecular weight and processing condition effect on the phase morphology, physical, thermal, and mechanical properties of RPET/ PP blends is very important to reveal before product design. This was approached by blending of RPET with PP (RPETIPP) using a single-screw extrusion process in the presence of various amounts of compatibilizer ranging from 0-35 wt% based on the PP content. From the morphological analysis, it is observed that the size of dispersed PP phase in RPET/ PP blend was dependent upon PP content and amount of compatibilizer that is it increases as PP content increased. The addition of compatibilizer of up to 15 wt% resulted in a size reduction of the dispersed phase (from 1.8/(mu)m to <0.43 (mu)m) and particle size distribution becomes narrower. The changes in morphological structure significantly affect the tensile and impact resistance of the moldings. An elongation at break (EB) of more than 350% could be achieved with the incorporation of just 5 wt% of compatibilizer (as compared to <90% EB for un-compatibilized specimens) while significantly better impact performance was observed in all compatibilized specimens.