ACID-DYEABLE COPOLYESTER AND PREPARATION METHOD THEREFOR

The present invention relates to an acid-dyeable copolyester and a preparation method therefor. The preparation method comprises: using a one-pot method to prepare a mixture of BHET and quaternized BHET, then performing a polycondensation reaction to prepare an acid-dyeable copolyester; The process for preparing the mixture of BHET and quaternized BHET comprises: first using protonic acid and Lewis acid to perform synergistic catalysis, and using paraformaldehyde to perform monochloromethylation on BHET to obtain a mixture of BHET and monochloromethylated BHET, and then performing quaternization modification on the mixture to obtain a mixture of BHET and quaternized BHET; the product is a random copolymer, and the molecular chain is composed of an M1 repeating unit and an M2 repeating unit. The preparation method of the present invention is simple, the product of the present invention can be dyed by acid dyes at normal temperature and normal pressure, has high dye uptake, high color fastness and good thermal