Abstract:
The effect of the mixing condition in a mill-type mixer on the thermal property and the crystal formation of the
poly(L-lactide)/poly(D-lactide) blends is investigated. The blends melt-mixed at 200 and 210 8C under application of a high shear flow
tend to show a single melting peak of the stereocomplex crystal (SC) in the differential scanning calorimetry first and second heating
processes without indicating the trace of the melting of homo-chiral crystal. The mixing at an elevated temperature causes a serious
thermal degradation. Further kneading of the blends at an elevated temperature higher than Tm of SC causes the transesterification
between the same enatiomeric chains forming block copolymers of L- and D-chains. This block copolymer acts as a nucleating agent
of SC and the compatibilizing agent between poly(L-lactide) and poly(D-lactide) and promotes the formation of SC. VC 2017 Wiley
Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45489.
