Biodegradable thermoplastic elastomer comprising PLLCA and CaCO₃ whiskers: mechanical properties, thermal stability and shape memory properties

A biodegradable and thermoplastic elastomer—poly(L-lactide-co-ε-caprolactone) (PLLCA)—was reinforced with 5, 10, 20, and 30 wt% of CaCO₃ whiskers. We assessed the influence of the CaCO₃ whisker content on the mechanical and thermal properties of the PLLCA/CaCO₃ whisker composites. Scanning electron microscopy (SEM) revealed that the CaCO₃ whiskers were uniformly distributed in the composite matrices. The results of differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) showed that the glass transition temperatures (T _g) of the composites increased slightly with increasing CaCO₃ whisker content. At low CaCO₃ whisker contents, the tensile strengths of the composites increased sharply with increasing CaCO₃ content, the Young’s moduli also increased, and the elongation at break values gradually decreased. Thermogravimetric analysis (TGA) showed that the CaCO₃ whiskers can promote the thermal degradation of PLLCA. Shape memory test results indicated that an appropriate amount of CaCO₃ whiskers can improve the shape memory properties of PLLCA.