poly(L-lactide) (PLLA) and poly (D-lactide) (PDLA) were synthesized using water as co-initiator. The double melting behavior of PLLA/PDLA stereocomplex crystal (Sc-crystal)was studied with DSC and in situ X-ray measurements. The oscillation phenomenon of melting peak area and melting point was discovered and investigated with the increase of isothermal time at 180℃. Through DSC and situ X-ray measurements
it is found that driving force of the oscillation in melting peak area is the instability of the massive isomers in the PLLA/PDLA Sc-crystal
which comes from the adjacent folding mechanism of crystal growth.