Recyclability of elastomer toughened recycled poly(ethylene terephthalate): The effect of grinding-extrusion-injection moulding on the mechanical and morphological properties of the blend

Abstract

Reprocessing potential of recycled poly(ethylene-terephthalate) (RPET)/ethylene-butyl-acrylate-glycidyl methacrylate (EBA-GMA) blends was investigated. PET flakes from food packaging were compounded with 0, 5, 10, 15 and 20 % EBA-GMA. Injection moulded specimens were produced, and some of the specimens were grinded, and reproduced to simulate real reprocessing. It was revealed by scanning electron microscopy that the distribution and particle size of the elastomer did not change notably after recycling. Noticeable degradation of the polymer matrix was observable after every processing step. Such deterioration of PET resulted in higher crystallinity and rigid amorphous fraction, as found by differential scanning calorimetry, which ultimately led to higher storage modulus, while the notched impact strength and elongation at break decreased. Nevertheless, the mechanical performance of the reprocessed RPET/EBA-GMA blends still significantly outperforms that of the neat PET recyclate. The degree of chain breakage was found to be the primary factor determining the recyclability of RPET/EBA-GMA blends.

Keywords

• poly(ethylene terephthalate)
• Elastomer
• Mechanical recycling
• Reactive extrusion
• Morphology
• Mechanical properties