Effect of PCL and EVA molar mass on the development of sustainable polymers

Biodegradable grafted copolymers, EVA-g-PCL, have been synthesized by reactive extrusion, through transesterification reaction between ethylene-vinyl acetate copolymer (EVA) and poly(ε-caprolactone) (PCL) using titanium propoxide (Ti(OPr)4) as catalyst. The effect of EVA and PCL molar mass on the amount of grafted copolymer and materials properties was investigated. The prepared blends were characterized by several analytical techniques, such as, selective extractions, rheology, TGA, DSC, SEM, mechanical properties, and the biodegradability was evaluated based on biochemical oxygen demand method. The results showed that the amount of copolymer increases as the amount of catalyst increases. Moreover, using EVA and PCL with high and low molar mass, respectively, allowed to obtain a material exhibiting properties similar to conventional polymers and higher biodegradability.The authors acknowledge the financial support given by FCT through the project PTDC/AMB/73854/2006 and the PhD grant SFRH/BD/29802/2006