Preparation of high-strength and high flame-retardant PMIA/P(an-VC) composite fibers and its conductive fibers

PMIA fiber has a wide range of applications in flame retardant protection, high temperature filtration and other fields. However, its poor mechanical properties result in a shorter service life of products made from it. In order to improve the mechanical properties of poly(metaphenylene isophthalamide) (PMIA) fiber and prepare PMIA conductive fiber, a highly oriented PMIA/Poly(acrylonitrile-co-vinyl chloride) P(AN-VC) composite fibers with excellent mechanical properties, flame retardancy and thermal stability were successfully prepared by wet spinning. The breaking strength of PMIA fiber at the maximum water bath stretching ratio was 1.58 cN/dtex and 10%P(AN-VC) composite fiber at the maximum water bath stretching ratio was 2.97 cN/dtex. The limiting oxygen index (LOI) of PMIA/P(AN-VC) composite fiber increased from 28.2% to 29.2%, which benefited from the excellent flame retardant properties of P(AN-VC). It was the addition of P(AN-VC) that weakens the hydrogen bonding between PMIA molecular chains resulting in an increase of the breaking strength of the composite fibers compared to PMIA fibers. In addition, the composite fibers could be prepared into conductive fibers and possessed excellent electrical conductivity.