| 摘要 |
A high-strength copolymerized aramid fiber of the present invention comprises an aramid copolymer containing a cyano group (-CN) substituted aromatic group, and has an intrinsic viscosity (IV) of 6.0-8.5, a polydispersity index (PDI) of 1.5-2.0, a strength of 23-32 g/d, and an elastic modulus of 1,100-1,300 g/d. The high-strength copolymerized aramid fiber may be prepared by a method in which, when para-phenylenediamine, cyano-para-phenylene diamine, and terephthaloyl dichloride are sequentially added to and reacted with an organic solvent to prepare a copolymerized aramid fiber, a neutralizing agent is put into and dispersed in the organic solvent in a step before the reaction of the para-phenylenediamine, cyano-para-phenylene diamine, and terephthaloyl dichloride, which are dissolved in the organic solvent. In the present invention, hydrogen chloride (HCl) generated from the polymerization reaction of para-phenylenediamine, cyano-para-phenylene diamine, and terephthaloyl dichloride is directly removed by the neutralizing agent dispersed in the solvent, and is simultaneously changed into a metal salt, and therefore, acid crumbs are not generated and an additional salt is rather generated, and thus, an aramid copolymer, which has a high intrinsic viscosity (IV) and a low polydispersity index (PDI) since the gelation by the acid crumbs is delayed, that is, the reaction time is lengthened, and which also has excellent solubility in an organic solvent since the additional salt is generated, can be prepared, and a high-strength copolymerized aramid fiber can be prepared with favorable spinnability by using the aramid copolymer even without using sulfuric acid. |
