Polyacrylonitrile (PAN) and preparation method and use thereof

A method for preparing polyacrylonitrile (PAN), comprising the steps of:

• mixing raw materials for polymerization to obtain a suspension comprising the PAN, the raw materials comprising following components by weight:
• an acrylonitrile monomer
• 5 parts to 70 parts,
• a first auxiliary monomer
• 0 parts to 20 parts,
• a second auxiliary monomer
• 0.025 parts to 10 parts,
• a polymerization medium
• 20 parts to 90 parts,
• an initiator
• 0.001 parts to 4 parts,
• a chain transfer agent
• 0 parts to 5 parts, and
• a settling agent
• 0 parts to 30 parts;
• and removing unreacted monomers and unreacted polymerization medium in the suspension to obtain the PAN;
• wherein:
• the first auxiliary monomer is at least one item selected from the group consisting of a vinyl ester monomer, vinyl imidazole, 4-acryloyl morpholine, and styrene;
• the second auxiliary monomer is at least one item selected from the group consisting of a vinyl acid monomer, a vinylamine monomer, a vinylamide monomer, and an ammonium salt of a vinyl acid;
• and
• the polymerization medium is at least one item selected from the group consisting of dimethyl carbonate, diethyl carbonate, dibutyl carbonate, methyl hydrogen carbonate, ethyl methyl carbonate, propyl methyl carbonate, and butyl methyl carbonate.