CHARACTERIZATION OF REVERSE-OSMOSIS MEMBRANES PREPARED FROM THE OXIME OF POLY(4-VINYLPYRIDINE-CO-METHYL VINYL KETONE)

The copolymer (4VK) of 4-vinylpyridine (4VP) and methyl vinyl ketone (MVK) was nearly quantitatively converted into an oxime (4VKX) which could be complexed with various metal salts. 4VKX was compared with 4VK in their membrane performance. When crosslinked with divinyl sulfone (DVS), the 4VKX membrane showed a higher strength than cellulose acetate (CA) membrane and a higher performance than 4VK membrane crosslinked with dihydrazine derivatives. The most adequate DVS content and copolymer composition were found to be 25 mol% based on MVK oxime and 1:1, respectively. The crosslinking quaternization of 4VKX with diisobutane (DIB) very effectively improved water permeability, as did 4VK, and gave a membrane performance superior to that of 4VK. Some transport characteristics and compaction in a long-term operation were investigated and discussed.