Enhancement of mechanical, rheological and antifungal properties of polylactic acid/ethylene-vinyl-acetate blend by triacetin plasticizer

In this study, a compatible blend of 85 wt% polylactic acid and 15wt%poly(ethylene vinyl acetate) (PLA85/EVA15) was added with different amounts of Triacetin (TRI) as a plasticizer. The thermal, tensile, rheological, antifungal and morphological properties of the unplasticized blend, plasticized blends (PLA/EVA-TRI) and plasticized PLA (PLA/TRI) were studied. Thermal stability improved as TRI increased up to 20 wt% while crystallinities continuously increased in the presence of 5-25 wt%TRI. The presence of 15 wt% TRI revealed tensile strength reduced to 21.28 MPa but toughness significantly improved when elongation at break increased up to 280%. At a similar amount of plasticizer based on the weight of the compound, PLA85/EVA15-TRI25 showed comparable thermal properties and tensile strength but higher elongation at break compared with PLA80/TRI20 indicating the importance of EVA in improving the properties of plasticized PLA. Antifungal ability against Aspergillus sp., Penicillium sp, and Fusarium sp improved with the increasing amount of TRI.

Automated summary

In this study, a compatible blend of 85 wt% polylactic acid and 15 wt% poly(ethylene vinyl acetate) (PLA85/EVA15) was plasticized with different amounts of Triacetin (TRI). The thermal, tensile, rheological, antifungal, and morphological properties were investigated. The results showed improved thermal stability and increased crystallinity with increasing TRI content. The presence of 15 wt% TRI reduced the tensile strength but significantly improved the toughness. PLA85/EVA15-TRI25 exhibited comparable thermal properties and tensile strength but higher elongation at break compared to PLA80/TRI20, highlighting the role of EVA in enhancing the plasticized PLA properties. Antifungal ability against Aspergillus sp., Penicillium sp., and Fusarium sp. improved with increasing TRI amount.