DRYING INDUCED PHASE SEPARATION IN MULTICOMPONENT POLYMERIC COATINGS SIMULATION STUDY

Phase separation simulation study related to cellulose acetate-water-acetone has been done. Results show that porous asymmetric and symmetric membranes can be produced by changing the nonsolvent concentration or by the drying conditions without altering the polymer content using dry-casting process. Dry-casting process is the process in which complete evaporation of solvent and nonsolvent takes place. At low initial nonsolvent concentration phase separation may not take place and dense polymer film may be obtained rather than a porous membrane. At high air velocity the phase separation is completely suppressed and uniformly dense coating devoid of substantial microstructure will result.