A chemical view onto post-consumer poly(ethylene terephthalate) valorization through reactive blending with functionalized polyolefins

The recovery of poly(ethylene terephthalate) from postconsumer packaging products, such as beverage bottles, allowed to obtain flakes with a purity level suitable for reprocessing. Among many possibil ities, the blending with polyolefins can provide toughened materials but, as poly(ethylene terephthalate) and polyolefins are immiscible, different methods of reactive compatibilization were followed to achieve a fine dispersion of polyolefln domains into a poly(ethylene terephthalate) matrix. In this meanwhile the use of a functionalized polyolefin, bearing reactive groups toward poly(ethylene terephthalate) terminals, is a prom ising route to obtain grafted copolymers acting as interface stabilizers. In particular, the use in the melt blend ing of ester or hydroxyl functionalized polyolefins in the presence of transesterification catalysts and/or anhy dride functionalized polyolefins as compatibilizer precursors were both investigated by focusing onto chem ical aspects. The prepared blends were analyzed through suitable fractionation methods, such as selective extractions, and spectroscopic analysis in order to identify the molecular architecture of the macromolecules resulting from the process and study their effectiveness at the interface region. Moreover the phase morphol ogy and the thermomechanical properties were investigated and correlated to the structure of the macromo lecular species in the system