Effect of molecular weight on crystallization behavior of poly (lactic acid) under isotherm and non?isotherm conditions

The effect of molecular weight on the crystallization behavior poly(lactic acid) (PLA) both isothermally and non-isothermally was studied using differential scanning calorimetry polarized optical microscopy. Two distinct crystal forms (? ??) were investigated under normal conditions for different weights. Using microscopy, growth rate spherulites measured nucleation estimated. Heterogeneous morphology with a variant ? ?? have been proposed. Spherulites from low mass PLA contained more interlamellar amorphous phase. In addition, results showed rapid than form in isothermal conditions.