Thermal and Mechanical Properties of Biodegradable Star-ShapedLinear Polylactide Stereocomplexes

Abstract EN

The 6-arm star-shaped poly(L-lactide) (6PLL)/linear poly(D-lactide) (1PDL) stereocomplex films were prepared by the solvent casting method.

The influences of the 6PLL/1PDL blend ratios (75/25, 50/50, and 25/75 w/w) and 1PDL molecular weights (15,000, 30,000, and 60,000 g/mol) on the thermal and mechanical properties of the stereocomplex films were investigated.

The 6PLL and 1PDLs had a single melting temperature (Tm) of homocrystallites at 174°C and 167°C, respectively.

The 6PLL/1PDL blends had two Tms: a lower Tm of homocrystallites (160–173°C) and a higher Tm of stereocomplex crystallites (219–228°C).

The stereocomplex crystallinity and mechanical properties of the 6PLL/1PDL blend films were higher than those of 6PLL and 1PDL and were the highest in the 50/50 (w/w) blend ratio.

However, the stereocomplex crystallinity of the 50/50 (w/w) 6PLL/1PDL blend films decreased and the mechanical properties increased as the molecular weight of 1PDL increased.