Toughening of Poly(L-lactide) with Branched Multiblock Poly(ε-caprolactone)/poly(D-lactide) Copolymers

A total biodegradable elastomer, branched multiblock poly(ε-caprolactone)/poly(D-lactide) (BMCD) was prepared using 3-isocyanatopropyltriethoxysilane (IPTS) as a coupling agent. To improve the toughness of poly(L-lactide)(PLLA), PLLA/BMCD blends were prepared via a simple solvent evaporation method at various BMCD loadings. Tensile test showed that the elongation at break of PLLA blends increased to 50.97% and 104.55% at the loadings of 5% and 7% (mass fraction) BMCD respectively, with no sacrifice of their biodegradability. This approach allowed for simultaneous control of mechanical and biodegradable properties of PLLA with a few additives in actual production. Furthermore, UV-VIS test showed that the light transmittance of the films at the loadings of 5% (mass fraction) BMCD was almost the same as pure PLLA at 400 nm.