Analysis of the mechanical properties of solvent cast blends of PLA/PCL

Polylactic acid (PLA) is the most promising material in the biodegradable category.However, brittleness and poor thermal stability restrict its application. To overcome this limitation,PLA may be blended with other biodegradable materials to tailor its properties while maintainbiodegradability. In this study a series of blends of PLA and poly (ε-caprolactone) (PCL) with variousmass fractions were prepared by solution method and solvent casting. Films of each blend wereformed when the solvent evaporated. Subsequently, tensile test samples were punched out of the filmfor testing and tensile testing, Fourier transform infrared spectrometry (FTIR), Differential scanningCalorimetry (DSC) and contact angle measurements were carried out. Since PCL is a ductile material,the two materials were blended together in an effort to improve the mechanical properties. However,on thermal analysis of the blends, two individual melting peaks were observed in the DSCthermograms. Furthermore, no significant shift in peaks was observed on the FTIR spectra, and cleardroplets and boundaries between two components of the blend can be observed in morphology study,all indicated the immiscibility of PLA and PCL. Tensile test showed poor mechanical properties dueto the poor adhesion of the two immiscible components of the blend, and the addition of PCL did notinfluence the wettability of the surface of the blends as there were no significant differences in contactangle measurements.