| 초록 |
We have reported, for the first time, that the endothermic heat concurrent with shrinkage was observed just above the glass transition temperature for drawn poly(lactic acid)(PLA) films, which is caused by drawing. It is considered that the endothermic heat is originated from both the recovered enthalpy and the work according to the shrinkage. In order to unravel experimentally the origin of endothermic heat, both the endothermic heat flow and the work with variation of length of PLA films were measured by DSC and UTM, respectively. In addition, the effects of draw ratio and draw temperature on the endothermic heat were investigated systematically. |
