Method for grafting SWNT (single-walled carbon nanotube) into modified PIPD (poly[2,5-dihydroxy-1,4-phenylenepyridinodiimidazole])

The invention which relates to a method for grafting modified PIPD concretely relates to a method for grafting SWNT into the PIPD and solves problems of easy agglomeration, difficult dispersion and difficult formation of a stable covalent connection of the SWNT with the PIPD in PIPD matrixes. The method is realized by mixing a methanesulfonic acid solution of the PIPD with a carboxylated SWNT dispersion liquid and reacting. According to the invention, the grafting of the SWNT into the modified PIPD is realized, and a SWNT grafted PIPD copolymer is generated. By utilizing the template effect of the SWNT to the fiber orientation, a PIPD fiber is induced to be further oriented along an axial direction, so mechanical properties are improved. The operation of the method is simple.