Method and device for preparing modified poly (m-phenylene isophthalamide) (PMIA) fiber by continuous polymerization-dry-wet spinning

A method for preparing a modified poly (m-phenylene isophthalamide) (PMIA) fiber by continuous polymerization-dry-wet spinning, comprising the following steps:

• (1) preparing a mixed solution of m-phenylenediamine (MPD) and a copolymerized diamine monomer;
• (2) mixing isophthaloyl chloride (IPC) with the mixed solution of the MPD and the copolymerized diamine monomer, and conducting pre-polycondensation to obtain a prepolymer;
• and conducting polycondensation on the prepolymer to obtain a modified PMIA resin solution;
• and
• (3) subjecting the modified PMIA resin solution to additive addition, filtration, defoaming, and dry-wet spinning to obtain the modified PMIA fiber,
• wherein in step (3), the modified PMIA resin solution is added with an organic additive capable of forming a hydrogen bond with an amide group before the filtration;
• wherein the organic additive is at least one selected from the group consisting of low-molecular-weight alcohol and acid, and a high-heat-resistant silicone;
• the low-molecular-weight alcohol and acid are at least one selected from the group consisting of trifluoroacetamide, trifluoroethanol, trifluoroacetic acid, hexafluoroisopropanol, ethylene glycol, glycerol, sorbic acid, and salicylic acid, and are added at 0.01 wt % to 3 wt % of a dosage of the modified PMIA resin solution;
• and the silicone is at least one selected from the group consisting of a polyether-modified polysiloxane and a fluorine-containing or alkoxyl-containing or hydroxyl-containing polysiloxane, and is added at 0.1 wt % to 10 wt % of a dosage of the modified PMIA resin solution.