Membranes composites preparees a partir d'alcool polyvinylique et de diisocyanate de toluylene destinees a l'osmose inverse

Composite reverse osmosis membranes have been prepared by coating a Millipore filter with an ultrathin layer of polyvinyl alcohol crosslinked by toluene diisocyanate. The membranes present a good selectivity towards aqueous salt solutions (for instance water flux of 500 liters/m²-day at 28°C, salt rejection of 98% with a 3.5% NaCl solution under a pressure of 100 bars) and have better temper-ature and pressure stabilities than cellulose acetate membranes. Their resistance to acid and alkaline hydrolysis is satisfactory. The influence of different preparation factors on the osmotic properties of the membranes was examined.