Syntheses of intrinsically flame‐retardant polyamide 6 fibers and fabrics

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.

Dual catalysis with an N‐heterocyclic carbene and a Lewis acid: Thermally latent precatalyst for the polymerization of ε‐caprolactam

“…Relative viscosities were determined in H 2 SO 4 with the aid of an Ubbelohde viscosimeter. Number‐average molecular weights were determined therefrom with the aid of literature values (see SI) 49–50 . Increasing molecular weights correlate well with increasing monomer to initiator ratios.…”

“…Number-average molecular weights were determined therefrom with the aid of literature values (see SI). [49][50] Increasing molecular weights correlate well with increasing monomer to initiator ratios. Although the values found by this method are in good accordance with the stoichiometry, they still represent estimated values and should not be used as exact but, instead, as qualitative measures.…”

A Spirocyclic Parabanic Acid Masked N‐Heterocyclic Carbene as Thermally Latent Pre‐Catalyst for Polyamide 6 Synthesis and Epoxide Curing

“…In line with the higher activator content, melting points ( T m ) of the resulting PA6 are somewhat lower (205–215 °C) than the one of PA6 prepared by anionic polymerization ( T m ≈ 220 °C). [ 49 ] Indeed, the reaction solidified in an acceptable time span with quantitative polymer yield even in the absence of CLA‐Ac (Table 2, entry 3).…”

Functionalization of polymers and nanomaterials for water treatment, food packaging, textile and biomedical applications: a review

“…The presence of phosphorus groups in the structure of this textile was the main reason of its flame-retardant ability. Moreover, it was shown that the presence of the organophosphorus compounds in the structure of polyamide had no negative effect on its other features (Mourgas et al 2019).…”