Preparation method for composite forward osmosis membrane based on interfacial polymerization

The invention relates to a preparation method for a composite forward osmosis membrane based on interfacial polymerization. Polyvinyl alcohol is used as a hydrophilic modification material of polyvinylidene fluoride, caprolactam is used as a diluent, and a thermally induced phase separation method is applied to prepare a hydrophilic modified polyvinylidene fluoride base membrane under a relatively low temperature condition, the base membrane is symmetrical in structure and high in porosity, and the upper and lower surfaces are rough and have micropore structures; and m-phenylenediamine is used as a water-phase monomer, trimesoyl chloride is used as an oil-phase monomer, and interfacial polymerization is performed on the surface of the polyvinylidene fluoride base membrane to prepare the composite forward osmosis membrane with excellent chemical stability. The composite forward osmosis membrane is high in water flux and low in reverse osmosis percentage of salts, and the composite forward osmosis membrane has