Development and Characterization of Fire Retarded Glass-Fiber Reinforced Poly(1,4-butylene terephthalate) Composites Based on a Novel Flame Retardant System

Insight into Hyper-Branched Aluminum Phosphonate in Combination with Multiple Phosphorus Synergies for Fire-Safe Epoxy Resin Composites

Epoxy resin (EP) has widespread applications in thermosetting materials with great versatility and desirable properties such as high electrical resistivity and satisfactory mechanical properties. At present, 9,10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) is widely applied to EP matrix for high flame resistance. Nevertheless, EP/DOPO composites acquire highly toxic decomposition products and smoke particles produced during combustion due to the gaseous fire-inhibition mechanism, which will be a major problem. To address this concern, an effective hyper-branched aluminum phosphonate (AHPP) was rationally designed and then coupled with DOPO into EP matrix to fabricate the fire-safe epoxy resin composites. On the basis of the results, significant increment in limiting oxygen index value (an achievement of 32% from 23.5% for pristine EP) and reduction in peak heat release rate and total heat release (59.4% and 45.6%) with the DOPO/AHPP ratio of 2:1 were recorded. During the cone calorimeter test, both the smoke production and total CO yield of EP-4 composite with the DOPO/AHPP ratio of 1:2 were dramatically decreased by 42.7% and 53.6%, which was mainly associated with the excellent catalytic carbonization of AHPP submicro-particles for EP composite. Future applications of submicro-scaled flame-retardant with various phosphorus oxidation states will have good prospects for development.

Preparation and characterization of chitosan derivatives and their application as flame retardants in thermoplastic polyurethane

Our previous work has demonstrated that chitosan (CS) can be directly used as charring agents. In this paper, efforts were made to further improve the thermal stability and charring ability of CS by reacting with benzaldehyde, salicylaldehyde and hydroxybenzaldehyde respectively to obtain different CS derivatives. CS derivatives in association with ammonium polyphosphate (APP) was then introduced into thermoplastic polyurethane (TPU) to prepare flame retardant TPU composites. The sample containing 18.75% APP and 6.25% salicylaldehyde modified CS (SCS) achieved the maximal limiting oxygen index of 29.5%, passed the V-0 rating and significantly decreased the peak heat release rate from 840.8kW/m² of neat TPU to 206.2kW/m². Thermogravimetric analysis and char morphology observation demonstrated that SCS/APP could promote the char formation to form more intact intumescent char structure. It was proposed that the synergism between CS derivatives and APP might be responsible for the improvement of flame retardancy.

Simultaneous enhancements in the mechanical, thermal stability, and flame retardant properties of poly(1,4-butylene terephthalate) nanocomposites with a novel phosphorus–nitrogen-containing polyhedral oligomeric silsesquioxane

A novel functionalized POSS greatly reinforced the mechanical, thermal stability, and flame retardant properties of PBT.

Synergistic effects between [Emim]PF6 and aluminum hypophosphite on flame retardant thermoplastic polyurethane

Synergistic flame retardancy of ionic liquid ([Emim]PF₆) and AHP on TPU has been studied. AHP was used as the main flame retardant and [Emim]PF₆ was used as the catalytic/synergistic agent.

Combination effect of MoS2 with aluminum hypophosphite in flame retardant ethylene-vinyl acetate composites

A series of flame retardant ethylene-vinyl acetate (EVA) composites, with different aluminum hypophosphite (AHP), melamine cyanurate (MCA) and MoS₂ content, has been prepared.