Poly(lactic acid) plasticized with low‐molecular‐weight polyesters: structural, thermal and biodegradability features

• Published in: Polymer international Vol. 66; no. 6; pp. 761 - 769
• Main Authors: Cicogna, Francesca, Coiai, Serena, De Monte, Cristina, Spiniello, Roberto, Fiori, Stefano, Franceschi, Massimiliano, Braca, Francesca, Cinelli, Patrizia, Fehri, Seyed Mohammad Kazem, Lazzeri, Andrea, Oberhauser, Werner, Passaglia, Elisa
• Format: Journal Article
• Language: English
• Published: Chichester, UK John Wiley & Sons, Ltd 01.06.2017; Wiley Subscription Services, Inc
• Subjects: Acids; Additives; Adipic acid; Biodegradability; Carboxylic acids; compostability; Data processing; Evaluation; low‐molecular‐weight polyesters; Molecular structure; Molecular weight; Oligomers; Physical characteristics; Physical properties; PLA; plasticizer; Polyester resins; Polyesters; Polylactic acid; Structural stability; Tensile tests; Thermal stability; Thermodynamic properties
• ISSN: 0959-8103; 1097-0126
• DOI: 10.1002/pi.5356

Poly(lactic acid) (PLA) was plasticized with ester oligomers having different structure, molecular weight and carboxylic acid content as end‐functionalities. In particular PLA oligomers and a low‐molecular‐weight polyester of adipic acid and 1,2‐propanediol (an adipate‐based derivative) were used and compared. The plasticizing capability was tested and the final structural and thermal properties of PLA matrix were evaluated by correlating the various features to the chemical and physical characteristics of these additives. SEC, DSC, TGA, tensile tests, XRD and SEM results, even after annealing, were collected, and the related data analysed and evaluated with reference to additive starting properties. All the oligoesters were able to generate flexible compounds, but PLA oligomers provided mixtures with reduced structural and thermal stability. Finally, the best performing blend was tested for biodegradability to definitely assess the material suitability for the final application (sustainable packaging). © 2017 Society of Chemical Industry Flexible materials were obtained by melt mixing poly(lactic acid) (PLA) with oligoesters having various structures and molecular weights whose effect on the structural and thermal stability of blends was investigated in depth together with the biodegradability performance of the most promising blend.