Co-agent mediated functionalization of LDPE/iPP mixtures for compatibilization of WEEE-recovered PVC

Mixtures of LDPE/iPP 80/20 w/w were functionalized in the melt by using maleic anhydride (MAH) as the functionalizing agent, 2,5-bis(tert-butylperoxy)-2,5-dimethylhexane (L101) as the peroxide initiator and butyl 3- (2-furyl) propenoate (BFA) as a coagent suitable to prevent the degradation of iPP and to promote the inter-macromolecular reactions. The use of BFA aimed at favouring the control of radical-induced side reactions and the formation of interfacial graft copolymers. The functionalization degree (FD) and the modification of macromolecular architecture, which were evaluated by selective solvent extractions combined with IR, DSC and SEM analyses, were modulated by varying the L101/MAH/BFA ratio in the feed. The optimized product in terms of FD value and processability was successfully tested as compatibilizer in a polyolefin/PVC mixture, where the PVC component resulted from the management of waste of electrical and electronic equipment (WEEE).