Abstract:
The cloud point temperatures of poly(
L-lactide) solutions were measured by stepwise warming. According to the relation between volume fraction of poly(
L-lactide) and cloud point temperature, the
θ temperature of poly(
L-lactide) solutions were obtained. The
θ temperatures of poly(
L-lactide) in 2-hexanone, cyclohexanol, ethyl lactate, bromobenzene, cyclohexanone, and chlorobenzene are 434.22, 422.12, 414.08, 408.00, 399.36 K and 392.46 K, respectively. The variation of
θ temperature accords with the principle of similar solubility parameter. The
θ temperature decreases with the decrease of the absolute value of the solubility parameter difference between poly(
L-lactide) and the solvent. Meanwhile, the
θ temperature decreases with the decline of interaction parameter. The exponential function can accurately express the relationship between
θ temperature and solubility parameter absolute difference as well as the relationship between
θ temperature and interaction parameter.