1989 Volume 45 Issue 3 Pages 95-101
The asymmetric cellulose acetate (CA) and polyimide (PI) membranes were prepared for reverse osmosis and were annealed at various temperature. After drying, thermal analyses, DSC and TG, were carried out for the membranes. The following results were obtained.
(1) As to CA membranes, glass transition temperature (Tg) is 491±5K. Crystallization temperature (Tc) and melting point (Tm) are very near and both fall in the range of 597±10K. Onset point of thermal decomposition (Td) is 627±10K from DSC and is 606±10K from TG. Vicedispersion temperature (Tβ) does not appear.
(2) As to PI membranes, Td appears 796±10K at DSC curve and 807±10K at TG curve, but neither Tg nor Tm appear at DSC and TG curves. It is confirmed that PI membrane has high heat endurance.
(3) Tg, Tm, and Td are almost independent of the heat annealing temperature.
