Résumé
Melt-crystallization behavior of poly(L-lactide) (PLLA) synthesized by Zn metal was investigated by using DSC, WAXD and POM. The crystallization behavior from the melt was investigated in the range from 368 to 398 K. The thicknesses of lamellae was (14 +/- 1) nm, and the thickening effect was not obvious. The results were treated with Avirami equation and Arrhenius equation. Avrami index n is 3 +/- 0.3 which means that spherulites morphology of PLLA crystals formed in the temperature range; A maximum in the crystallization kinetics was observed around 378 K; half time of crystallization at 378 K was about 5.2 min. Lauritzen-Hoffmann(LH) theory was used to investigate the crystallization mechanism of PLLA, presenting the transition from regime II to regime III is approximately 380 K. The values of K-g(II) and K-g(III) were 4.57 x 10(5)K(2) or 1.115 x 10(6)K(2), respectively. And K-g(III)/K-g(II)=2.44, which accords with the value forecasted by LH theory.