Toughening of Poly(l-lactide) with Methyl MQ Silicone Resin

Poly(l-lactide) (PLLA)/Methyl MQ (M: mono-functional silicon–oxygen unit R3SiO1/2, abbreviated as M; Q: tetra-functional silicon–oxygen unit SiO2, abbreviated as Q) Silicone Resin (Me-MQ) blends were prepared via a simple solvent evaporation method at various Me-MQ loadings. PLLA is high in strength and modulus, but its applications are limited partly due to its inherent brittleness. It is difficult to keep both toughness and transparency for modified PLLA without compromising its tensile strength and biocompatibility. In this study, we used biocompatible Me-MQ to toughen PLLA at low loadings. The elongation at break of neat PLLA is 7.8%. Tensile test showed that the elongation at break of PLLA blends increased to 67.9% and 217.7% at the loadings of 1 and 2 wt% Me-MQ respectively, with no sacrifice of their strength. UV–vis test showed the light transmittance of the films at the loadings of 1 wt% Me-MQ is almost the same as neat PLLA.