Effect of the Processing-Induced Morphology on the Mechanical Properties of Biodegradable Extruded Films Based on Poly(lactic acid) (PLA) Blends

SICCARDI, MATHILDE; GARCIA-FONTE, XOAN XOSÉ; SIMON, ANTOINE; PETTARIN, VALERIA; ABAD, MARÍA JOSÉ; BERNAL, CELINA

JOURNAL OF POLYMERS AND THE ENVIRONMENT

SPRINGER/PLENUM PUBLISHERS

Año: 2019 vol. 27 p. 2325 - 2333

1566-2543

Biodegradable films based on poly(lactic acid) (PLA)blends were obtained by cast extrusion. Theirtensileand fracturebehavior wasinvestigated and the effect of the processing conditions through the extrusion rolling speedon this behavior was analyzed.In uniaxial tensile tests,all filmspresentedcompletely ductile behavior exhibiting a definedyield point, strain softening after this point and a plateau before fracture. Fracture behavior was determined through quasi-static fracture tests on deeply double edge notched tensile (DDENT) specimens. The film obtained at the lowest rolling speed exhibited completely ductile behavior hence, the Essential Work of Fracture methodology was applied to characterize its fracture. The film processed at intermediate rolling speed, on the other hand, presented ductile fracture or ductile instability depending on the ligament length and the film obtained with the highest rolling speed exhibited a transition regime fracture. In order to compare the fracture behavior of the different films, the J-Integral at maximum load Jmax was adopted.Differences in the films fracture behavior were correlated to the processing-induced morphology.