Abstract: Maleic anhydride (MA) was grafted onto polypropylene random copolymer (PPR) with a grafting reactive extruder, and the grafted product (PPR-g-MAH) was used as a toughening agent for recycled PET flakes (r-PET) in a condensation reactive extruder. The optimal recipe for PPR-g-MAH was obtained as: 3 % of MAH, 0.03 % of initiator DCP. The mechanical properties of r-PET/PPR-g-MAH alloy were optimal when grafting rate was 4.2 mmol/100g and PPR-g-MAH content was 10 %. SEM showed that with MA grafted, PPR achieved a finer dispersion in r-PET compared with neat PPR.

Key words: recycled bottle flakes, random polypropylene, poly(ethyleneglycol terephthalate), reactive extrusion, toughening