Morphology and properties of microfibrillar composites based on recycled poly (ethylene terephthalate) and high density polyethylene

Microfibrillar composites (MFCs) from recycled high density polyethylene (R-HDPE)/recycled poly (ethylene terephthalate) (R-PET) (75/25 w/w) were made through reactive extrusion and post-extrusion strand stretching. The resultant MFCs could be processed at HDPE processing temperature. The compatibility between microfibers and R-HDPE matrix was improved through compatibilizers. Of the three compatibilizers evaluated, ethylene glycidyl methacrylate copolymer (E–GMA) performed the best. The addition of compatibilizers did not obviously change the size of R-PET fibers in MFCs. The toughness of MFC was significantly enhanced, and R-PET phase did not crystallize when 5% E–GMA was used. The process of manufacturing MFCs provides a way to recycle commingled plastics, and MFCs would be potential matrices for natural fiber polymer composites.