Synthesis of a Cyclophosphazene Derivative Containing Multiple Cyano Groups for Electron-Beam Irradiated Flame-Retardant Materials

Abstract

A cyclophosphazene derivative containing multiple cyano groups, denoted as hexa(4-cyanophenoxy)cyclotriphosphazene (CN-CP), was synthesized by a one-step nucleophilic substitution reaction for a phosphorus–nitrogen flame retardant. To meet the strict requirement of safe and environment-protective insulation materials, a series of composites based on low-density polyethylene-poly(ethylene-co-vinyl acetate) containing CN-CP/Mg(OH)2/Al(OH)3 organic-inorganic synergistic flame retardants was fabricated. High-energy electron beam irradiation was subsequently applied to obtain a halogen-free flame-retardant crosslinked system. The relationship between crosslinking degree and irradiation dose was studied, and crosslinking degrees ranging within 63%–85% were obtained under 100–190 kGy. Furthermore, the effects of CN-CP filler and irradiation dose on the properties of the composites were carefully investigated. The maximum tensile stress and limiting oxygen index values of most composites irradiated by EB were more than 15 MPa and 28%. Results revealed that the obtained materials had excellent thermal and mechanical, flame-retardant, and insulation properties, thereby suggesting their promising prospects for wire and cable applications.

Radiation crosslinked ethylene vinyl acetate composite with binary flame retardant: The improved performance and mechanisms

“…While the number of filling portions of MCA continuously decreases, the intensity of the N–H and C–H characteristic peaks at 3385 and 3194 cm −1 and the CN and C–N characteristic peaks at 1665 and 1419 cm −1 are attenuated. [ 19,20 ] At the same time, it can also be seen from the curve that the peak at 936 cm −1 disappeared after irradiation crosslinking, because TAIC participated in the graft reaction during electron beam irradiation, thus destroying its own structure, making the absorption peak of double bond of TAIC disappear, which indicates that the double bond of TAIC was opened and reacted during irradiation, and the reaction did not produce residue at all.…”

The Effect of Alkyl Terminal Chain Length of Schiff-Based Cyclotriphosphazene Derivatives towards Epoxy Resins on Flame Retardancy and Mechanical Properties

“…In comparison, the elongation decreased drastically when 1 wt% of FR additives was added; 15.74 and 4.71% for compounds 4a and 4b , respectively. The high content of inorganic particles somehow affects the deterioration of flexibility when added to a polymer matrix [ 49 ]. Overall, these mechanical properties express the ability of a material to bear maximum load before breaking, the elasticity of a material, and the compatibility of the FR additives with the EP.…”