Effect of temperature on the thermal property and crystallization behavior of poly (lactic acid) porous membrane prepared via phase separation induced by water microdroplets.

Poly (lactic acid) (PLA)-based porous membrane were fabricated through phase separation induced by water microdroplets at different ambient temperature to unravel the relationship between the physical properties (including thermal properties and crystallization) and preparation temperature. Cross-sectional scanning electron micrographs revealed that the thickness of the membrane decreases with increasing temperature between 25 °C and 100 °C. In the bilayer structure, each layer has a different morphology. Differential scanning calorimetry (DSC) and X-ray diffraction studies indicate that the preparation temperature influences the ratio between imperfect and perfect crystals in the membrane, leading to a bimodal melting peak in the DSC thermogram. The change in the initial decomposition temperature in the thermogravimetric analysis curve is weak, suggesting a negligible effect of the preparation temperature on the thermal stability of the membranes. Thus, PLA porous membranes can be prepared with better crystallinity by controlling the ambient temperature during the phase separation induced by water microdroplets.