Abstract: Abstract:Differential scanning calorimctry (DSC) and wide-angle N-ray diffraction (W八ND) were usedin the characterization of crystallization behavior of uniaxially oricntded poly(lactic acid)(PI一八).In DSC experiment, two melting endothermic peaks were observed according to two crystal diffraction peaks at29 .9 0 and 31 0 in W八XD chart. It was found that orientation increased the degree of crystallinity andchanged PI一八’、crystal form. When temperature was above 110℃and the uniaxial stretch was more
than 4 times, some a crystal transformed to俘crystal. Talc could accelerate this process.!\ddition of 1 phr talc increased the degree of crystallinity from 18. 5%to 37.48%，and promoted the transforma-tion of crystal forms.

Key words: poly(lactic acid), uniaxial orientation, crystal form, crystallization behavior