Flame Retardancy Mechanisms of Aluminium Phosphinate in Combination with Melamine Cyanurate in Glass‐Fibre‐Reinforced Poly(1,4‐butylene terephthalate)

Abstract

The flame retardancy mechanisms of aluminium diethylphosphinate (AlPi) and its combination with melamine cyanurate (MC) in glass‐fibre‐reinforced poly(butylene terephthalate) (PBT/GF) were analysed using TGA including evolved gas analysis (TGA‐FTIR), cone calorimeter measurements using various irradiations, flammability tests (limited oxygen index, LOI, UL 94) and chemical analyses of residues (FTIR, SEM/EDX). AlPi decomposed mainly through the formation of diethylphosphinic acid and aluminium phosphate and influenced the decomposition of the PBT only slightly. AlPi acted mainly through flame inhibition. A halogen‐free V‐0 PBT/GF material was achieved with a LOI of 44%. Additional charring influenced the flammability. MC decomposed independently of the polymer and showed some fuel dilution effects.

Development of a Halogen Free Flame Retardant Masterbatch for Polypropylene Fibers

“…When MPh additive is introduced with MC (samples mf3 to mf5), the ignition time value is comprised between the raw sample and mf2, and at high ratio value tends to the mf2 one. The increase of ignition time may result from the fuel dilution of MC [35]. The influence of MPh on the HRR is limited for the samples mf3 and mf4, since the decrease of peak of heat release rate is close to mf2 one, whereas for a ratio of 3/1 (sample mf5) a higher variation of 30% was detected.…”

Effect of Meltable Triazine-DOPO Additive on Rheological, Mechanical, and Flammability Properties of PA6

“…This behavior was attributed to the decomposition or vaporization of the FR additive in the initial stage of polymer degradation, and also to the interactions of products obtained from the decomposition reactions of the polymer and additive. In fact, the thermal decomposition of Exolit OP 1230 in the PA6 formulation might be the result of the degradation of the additive and its vaporization, which might constitute the dominant process [41]. Former studies on PA6 formulations containing melamine or melamine derivatives also reveal an increased destabilization of the PA6 polymer caused by the incorporation of FR additives [8,38,39].…”

“…The higher amount of char registered for PA6/Exolit (8.9 wt %) when compared to the PA6/DTE-DOPO formulation (6.05 wt %) may be due to the generation of polyphosphoric acid and its salts in the case of Exolit OP 1230, which facilitates the formation of the carbonaceous layer [43]. It is known that the introduction of melamine destabilizes PA6 and leaves no char residue above 600˝C, while DOPO-based FR can exhibit both condensed and gas phase activity [8,41]. The 6.05 wt % char in the case of PA6/DTE-DOPO could be explained by the chemical modification of the melamine derivative which enables, as expected from the TGA data of the additive, the promotion of a carbonaceous layer.…”

Intumescent formulations based on lignin and phosphinates for the bio-based textiles

“…Neat Lignin shows a slow rate of weight loss from 60 to 300 °C, leading to the formation of a higher residue (~60 wt.%) at 600 °C. Phosphinates (AlP/ZnP) are also characterized by a sharp single degradation step occurring between 450 and 500 °C; in particular, ZnP shows a higher char residue (~20 wt.%) with respect to AlP (~7 wt.%) at 600 °C [5]. In the presence of lignin and phosphinates, the degradation of PA11 is shifted towards higher temperatures by about 50°C; furthermore, the char residue approaches about 10 wt.% at 600 °C.…”