Experimental investigation of mechanical, thermal, and flame‐retardant property of polyamide 6/phenoxyphosphazene fibers

Abstract

In this study, flame-retardant polyamide 6 (PA6) fibers incorporated with hexaphenoxycyclotriphosphazene (HPCP) were prepared by melt spinning. The effects of HPCP on the mechanical, thermal, and flame-retardant property of PA6 fibers were investigated. The results indicated that PA6 fibers containing less than 15 wt % of HPCP possessed acceptable spinnability. HPCP resulted in a slight decrease in tensile strength and tensile modulus, however, an enhancement of the flexibility. Thermal decomposition temperature of PA6 fibers reduced about 22 C but the residue at 800 C increased. At the loading of 10 wt %, PA6 fibers reached a limiting oxygen index value of 28.6% and had no smoldering time in the vertical oriented burning. Residue analysis by Fourier-transform infrared and scanning electron microscope revealed that a condensed phase mechanism was involved in the decomposition of PA6/HPCP system. Pyrolysis-gas chromatography-mass spectrometry results demonstrated that HPCP not affected the composition of the pyrolysis gases, but mainly intensified the effusion of nonflammable gases, which is positive to flame retardancy. Therefore, the PA6/HPCP composite fibers would get access to satisfactory applications as flame-retardant materials.

Flame Retardancy of Nylon 6 Fibers: A Review

“…Because of compatibility problems between small-molecule flame retardants and nylon 6, flame retardants often do not achieve good dispersion in the nylon 6 matrix, which directly affects the spinnability and mechanical properties of nylon 6 fibers [2]. In order to solve these problems, researchers have co-polymerized elements or structures that can exert flame-retardant effects from reactive monomers into polymer chains, thereby achieving flame-retardant effects [3].…”

“…Di et al [2] applied hexaphenoxycyclotriphosphazene (HPCP) for nylon 6 fibers by melting spinning method and studied the effects of HPCP on the mechanical, thermal, and combustion performances of composite fibers. HPCP mainly promotes charring through the formation of organophosphorus and aromatic products in the condensed phase.…”

Flame Retardant Treatments of Nylon Textiles: A Shift towards Eco-Friendly Approaches

“…In addition, this kind of facile application rarely alters the tensile properties of nylon substrate, which usually happens in the bulk state application of flame retardant compounds. In line, hexaphenoxycyclotriphosphazene (HPCP) [52], a petro-based phosphorus compound, is considered to modify the flame-retardant properties of nylon 6 fibers (see Figure 15a). Here, the nylon 6 chips are blended with the flame retardant compound (HPCP) and fibers are prepared via melt spinning process.…”

Smoldering suppression and synergistic effect of alginate fiber‐based composite paper by flame‐retardant lyocell fiber

“…Blending is a convenient but efficient method to overcome the shortcomings of a single fiber 28–31 . Due to the interaction between the components, the blend fibers can often obtain better flame retardancy, such as polyamide/phenoxyphosphazene fiber, 32 polyamide/alginate fiber, 33 flame‐retardant cotton/alginate fiber, 34 viscose/alginate 35 and so on. In particular, Zhang et al 2736 studied the flame retardancy of flame‐retardant viscose (FRV) and Ca‐Alg blend fiber bundles, phosphorus‐based flame‐retardants in FRV induce fiber dehydration and form a dense carbon layer, which effectively prevents heat transfer and further inhibits the smoldering of Ca‐Alg.…”