Syntheses of intrinsically flame‐retardant polyamide 6 fibers and fabrics

Abstract

ABSTRACT In this study, flame‐retarded polyamide 6 (FR‐PA6) was prepared via the direct co‐condensation of ε‐caprolactam with two different organophosphorus compounds in a typical melt‐polymerization process. Polymer microstructures, especially the incorporation of the phosphorus‐containing comonomers, as well as the thermal and physical properties of the resulting copolyamides have been studied in detail. The phosphorus‐modified PAs have a P‐content of 0.10–0.30 wt %, possess high relative viscosities of 2.2–2.4 and good thermal stability. FR‐PA6 multifilaments were prepared by melt spinning and show tensile strengths up to 40 cN/tex and tenacities up to 0.5 GPa. Knitted fabrics of FR‐PA6 exhibit high limiting oxygen index values around 35%. Due to the very low phosphorus content, there is no impairment of the material properties of PA6. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 47829.