Ductile-brittle transition behaviour of PLA/o-MMT films during the physical aging process
M. Ll. Maspoch, O. O. Santana, J. Cailloux, E. Franco-Urquiza, C. Rodriguez, J. Belzunce, A. B. Martinez
Vol. 9., No.3., Pages 185-195, 2015
DOI: 10.3144/expresspolymlett.2015.20
DOI: 10.3144/expresspolymlett.2015.20
Corresponding author: M. Ll. Maspoch 
GRAPHICAL ABSTRACT
ABSTRACT
The ductile-brittle transition behaviour of organo modified montmorillonite-based Poly(lactic acid) films (PLA/o-MMT) was analysed using the Essential Work of Fracture (EWF) methodology, Small Punch Tests (SPT) and Enthalpy relaxation analysis. While the EWF methodology could only be applied successfully to de-aged samples, small punch test (SPT) was revealed as more effective for a mechanical characterization during the transient behaviour from ductile to brittle. According to differential scanning calorimetry (DSC) results, physical aging at 30°C of PLA/o-MMT samples exhibited slower enthalpy relaxation kinetics as compared to the pristine polymer. Although all samples exhibited an equivalent thermodynamic state after being stored one week at 30°C, significant differences were observed in the mechanical performances. These changes could be attributed to the toughening mechanisms promoted by o-MMT.
