Flame retardancy and mechanical properties of a novel intumescent flame‐retardant unsaturated polyester

Abstract

A novel macromolecular intumescent flame retardant (MIFR) was synthesized. Unsaturated polyester (UP) filled with MIFR as flame-retardant additive was prepared. The effects of MIFR on properties such as tensile strength, impact strength, flame-retardant behavior, thermal stability, and morphology of char were studied. Its flammability and burning behavior were characterized by UL 94 and limiting oxygen index. Twenty-four percent of MIFR were doped into UP to get 30.5% of limiting oxygen index and UL 94 V-0, whereas its tensile strength and the impact strength were decreased by only 7.2% and 7.0%, respectively. Activation energy for the decomposition of samples was obtained by using the Kissinger equation. The results for UP containing MIFR, compared with UP, show that the weight loss, thermal stability, and the decomposition activation energy decreased, and the char yield increased, showing that MIFR can catalyze decomposition and carbonization of UP to form an effective charring layer to protect the underlying substrate. J. VINYL ADDIT. TECHNOL., 00:000-000, 2014.

Preparation of highly efficient flame retardant unsaturated polyester resin by exerting the fire resistant effect in gaseous and condensed phase simultaneously

“…It was speculated that the fire was suppressed by the flame inhibition effect in gas phase and the isolation effect of the formed char layer in condensed phase. Compared with the previous reported works, at least 24 wt% flame retardant were required to achieve the equal flame retardant level of UPR materials. For example, Chen et al added dimethyl methylphosphonate and ammonium polyphosphate into UPR and the sheets fulfilled UL‐94 V‐0 grade with an LOI value of 30.8% when the total loading amount of flame retardant was 25.9 wt%.…”

“…Among these flame retardant additives, the IFR system exhibited superior charring and dripping inhibition capability accompanied with low production of toxicity substances . Thus, IFR has aroused attention and is applied in flame retardant UPR materials . Colpankan et al incorporated ammonium polyphosphate (APP), expandable graphite, and aluminum tri‐hydroxide into UPR, and the samples achieved UL‐94 V‐0 rating with limiting oxygen index (LOI) value of 43% when the total addition amount of flame retardant was 40 wt%.…”

“…The ingredients of IFR existing in a single‐molecule can interact with each other more closely and quickly, and then exhibit much better synergistic effect . Gao et al synthesized a novel mono‐component intumescent flame retardant (MIRF) and then used to prepare flame retardant UPR. The UPR/24 wt% MIRF composites achieved UL‐94 V‐0 grade and the LOI value reached 30.5%, which presented higher flame retardant efficiency for UPR comparing with that of multi‐component IFR system.…”

“…The ingredients of IFR existing in a single-molecule can interact with each other more closely and quickly, and then exhibit much better synergistic effect. [21][22][23] Gao et al 19 24 the compound containing methylphosphonic acid unit exhibited the quenching effect for active free radicals and then interrupted the combustion chain reaction in the gas phase during combustion. 25 It would be an alternative approach for enhancing the flame retardant properties of UPR materials by using the mono-component IFR containing methylphosphonic acid groups.…”

Phosphorus–nitrogen‐type fire‐retardant vinyl ester resin with good comprehensive properties

“…However, as presented in Figure (b), as the amount of the flame‐retardant TGIC–AA–DOPO increased, the holes gradually disappeared, and a more continuous and compact char layer surface was formed. Such a structure is beneficial in isolating heat and hindering pyrolysis gas transport; thereby, it protects the underlying matrix from further combustion . The change in the char residue morphologies agreed well with the good flame retardancy of the TGIC–AA–DOPO/901‐VERs discussed in the sections on the LOI, UL‐94, and cone calorimetry tests.…”