Effect of conformation on the properties of uniaxially drawn polylacide films upon drawing temperature

Polylactide(PLA) films were drawn at various drawing temperature of 65, 90 and 120 A degrees C. The effects of drawing temperature on structural conformation and properties of PLA films were investigated. It was confirmed that the PLA films at drawing temperature of 65 and 90 A degrees C were composed of alpha' phase crystal form. The strain-induced crystallization and molecular orientation increased with increasing the draw ratio, which result in improving the mechanical and thermal properties of alpha' phase PLA films. However, at drawing temperature of 120 A degrees C, the strain-induced crystallization and molecular orientation of PLA films were not distinctly detected. It was supposed that the rate of the chain relaxation was faster than chain orientation and strain-induced crystallization during uniaxial drawing process