Scratch behavior of fully sustainable polylactide/modified natural Eucommia ulmoides gum thermoplastic vulcanizates

To make full use of the renewability of polylactide (PLA) and natural Eucommia ulmoides gum (EUG), novel fully sustainable thermal plastic vulcanizates (TPVs) with high toughness were developed via dynamic vulcanization technique based on modified EUG (referred to as EUG-GMA). The latter greatly improved the toughness of PLA and the mechanism was discussed with respect to micro structure analysis. Aiming at providing theoretical guidance for PLA/EUG-GMA TPVs in scratch related applications, the scratch behavior of TPVs with different EUG-GMA content was studied in single-pass and multiple-pass scratching mode, after which the tribological mechanisms were discussed based on worn surface morphology and contact area analysis. It is revealed that the promoted interfacial adhesion due to in-situ compatibilization and the co-continuous phase structure of PLA/EUG-GMA TPVs played crucial roles in enhancing the TPVs' toughness. In addition to tribo-conditions, the above mentioned interfacial performance was also responsible for the variation of scratch behavior of different TPVs. It is expected that the present study would open up a new route of manufacturing sustainable composites combined with scratch resistance and toughness.