The invention relates to a method for preparing a
polyvinylidene fluoride alloy film, which comprises the following steps: 1), uniformly mixing
polyvinylidene fluoride, hydrophilic copolymers and
caprolactam; 2, heating the mixed
polyvinylidene fluoride, hydrophilic copolymers and
caprolactam under the protection of
nitrogen to a solution temperature, and maintaining for 0.5-2 h at the temperature; 3), after the polyvinylidene
fluoride, hydrophilic copolymers and
caprolactam are completely solved, stirring for 0.5-1.5 h and then standing to obtain a
casting solution, and saving the
casting solution at the solution temperature; 4), fabricating the
casting solution to a film which is then placed in the air for natural cooling until complete solidification; and 5), finally, extracting caprolactam, actually the polyvinylidene
fluoride alloy film, through an extracting agent. The method has the advantages of simple technology, zero
contamination and lower cost. The prepared polyvinylidene
fluoride alloy film has the advantages of superior
chemical stability, high
mechanical strength,
contamination resistance and easiness in cleaning. The method provided by the invention can provide high-performance alloy film products for the MBR technology in the filed of
sewage disposal and water resource recycle, and has an extensive application in the fields of industry,
medicine,
sewage disposal and the like.