Preparation of a Novel Intumescent Flame Retardant Based on Supramolecular Interactions and Its Application in Polyamide 11

Abstract

The flammability and melt dripping of the widely used bio-based polyamide 11 (PA 11) have attracted much attention in the last decade, and they are still a big challenge for the fire science society. In this work, a novel single macromolecular intumescent flame retardant (AM-APP) that contains an acid source and a gas source was prepared by supramolecular reactions between melamine and p-aminobenzene sulfonic acid, followed by an ionic exchange with ammonium polyphosphate. The chemical structure of AM-APP was characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. AM-APP and TiO were then introduced into PA 11 by melt compounding to improve the fire resistance of the composite. The fire performance of PA 11 composites was evaluated by the limiting oxygen index (LOI), vertical burning (UL-94), and cone calorimetry tests. The results showed that the presence of 22% AM-APP and 3% TiO increased the LOI value from 22.2 to 29.2%, upgraded the UL-94 rating from no rating to V-0, completely eliminated melt dripping, and significantly decreased the peak heat release rate from 943.4 to 177.5 kW/m. The thermal behaviors were investigated by thermogravimetric (TG) analysis and TG-FTIR. It is suggested that AM-APP produces an intumescent char structure and releases inert gases, whereas TiO may consolidate the char layers, leading to the improvement in the fire resistance of PA 11.

Flame‐retardant cyanate ester resin with suppressed toxic volatiles based on environmentally friendly halloysite nanotube/graphene oxide hybrid

“…In addition, the residual mass of GHNT/CE after CONE testing is higher than the weight residue of the TGA test (Table ); this results from the formation of dense carbonaceous layers of GHNT/CE during combustion. Many studies have proved that an increased residual char is beneficial to building an effective physical barrier, providing a good thermal insulating effect and blocking the escape of degradation volatiles . Therefore, the condensed phase is the important flame‐retarding mechanism for 5.0GHNT/CE.…”

Synergistic effect of Nano‐ZnO and intumescent flame retardant on flame retardancy of polypropylene/ethylene‐propylene‐diene monomer composites using elongational flow field

“…Among them, the peaks at 3452, 3331, 959, and 932 cm −1 were assigned to NH 3 , while those at 2360, 1340, and 670 cm −1 were the characteristic absorption peaks of CO 2 . Furthermore, the peaks at 1625 and 1507 cm −1 were ascribed to the asymmetric and symmetric vibration peaks of NH 4 + or gaseous MEL resulting from the sublimation process . The infrared absorption spectral band of H 2 O Vapors at 3500–4000 and 1319–2000 cm −1 still existed, though with low signals.…”

Fire retardance and smoke suppression of polypropylene with a macromolecular intumescent flame retardant containing caged bicyclic phosphate and piperazine

“…Compared with a traditional IFR system, with the incorporation of 22 wt % PA‐APP, intumescent flame‐retardant polypropylene (IFR‐PP) passed the UL‐94 V‐0 rating with a limiting oxygen index (LOI) value of 31.2% . After that, a series of the modified APPs with phosphazene, triazine derivatives, melamine and p ‐aminobenzene sulfonic acid, vinyltrimethoxysilane, and allylamine have been unveiled and successfully applied to FR epoxy (EP), polyamide 11 (PA11), and polypropylene (PP) systems. In addition, another attempt combined an acid source, a charring agent, and a blowing agent in one compound via chemical reaction.…”