Abstract: Caprolactam（C6H11NO）is one of the most important material in the polymer industry, dehydration is the most important edulcoration technology in the final caprolactam purification. However ，caprolactam is heat-sensitive substance, for prevention of degradation under high temperature, the dehydration of caprolactam with pervaporation (PVP) is studied. Cotton as membrane material and is firstly dessloved in the alkaline solution, then the regenerated cellulose（RC）is prepared by phase inversion method. The influence of concentration of casting solution on the membrane structure is investigated. The results show that the 4 wt % cellulose concentration is suitable to prepare the PV membrane. But the flux and separation factor of pure RC membrane are not ideal. Therefore ，polyvinyl alcohol（PVA ），Polyvinyl-Py-rrolidone（PVP ）and β -cyclodextrin （β-CD ）are selected to modify the RC membrane. The degree of swelling ，contact angle and PV performance of the modified membranes are tested. RC-PVA has better properties and the strength ，the flux and the separation factor are improved. With the addition of β -CD ， the separation factor of membrane is enhanced, and it has a little influence on flux.

Key words: pervaporation , caprolactam-water mixtures , regeneration cellulose membrane , blend