Biodegradation and mechanical property of polylactic acid/thermoplastic starch blends with poly (ethylene glycol)

Abstract

The effects of adding poly (ethylene glycol) (PEG) into polylactic acid/thermoplastic starch blends (PLA/TPS) on the properties were investigated by DSC, SEM and mechanical property-testing. The blends of PLA/TPS blended with increasing content PEG exhibited lower temperature of glass transition (T _g) and lower temperature of melting (T _m) as well as higher melt flow index (MFI), which indicates the plasticization and processability of the composites were dramatically improved. The tensile strength, flexural strength and izod impact strength of PLA/TPS (80/20) increased at first and then decreased with increasing content of PEG due to stronger interfacial adhesion. The optimized mechanical property can be obtained for the blend with 3 wt % PEG. The samples containing PEG after soil burial for 5 months showed quicker degradation being accompanied with large weight loss and mechanical properties loss.

Keywords

biodegradation / mechanical property / polylactic acid / starch

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