Poly(lactic acid) (PLA) properties as a consequence of poly(butylene adipate-co-terephtahlate) (PBAT) blending and acetyl tributyl citrate (ATBC) plasticization

This study was aimed at the modulation of\npoly(lactic acid) (PLA) properties by the addition of both a\nlow-molecular-weight plasticizer, acetyl tributyl citrate\n(ATBC), and a biodegradable aliphatic–aromatic copolyester,\npoly(butylene adipate-co-terephthalate) (PBAT).\nPLA/PBAT, PLA/ATBC, and PLA/PBAT/ATBC mixtures\nwith 10–35 wt % ATBC and/or PBAT were prepared in a\ndiscontinuous laboratory mixer, compression-molded, and\ncharacterized by thermal, morphological, and mechanical\ntests to evaluate the effect of the concentration of either the\nplasticizer or copolyester on the final material flexibility.\nMaterials with modulable properties, Young’s modulus in\nthe range 100–3000 MPa and elongation at break in the\nrange 10–300%, were obtained. Moreover, thermal analysis\nshowed a preferential solubilization of ATBC in the PBAT\nphase. Gas permeability tests were also performed to assess\npossible use in food packaging applications. The results are\ndiscussed with particular emphasis toward the effects of\nplasticization on physical blending in the determination of\nthe phase morphology and final properties.