Frequent fire accidents and increasing environmental/health issues call for more durable and safer firefighting strategy for polymeric materials. Widely used small-molecule flame retardants are limited for their damage to thermal/mechanical properties, poor durability, undesirable persistence, bio-accumulation and toxicity (PBT). Herein, a novel macromolecular flame retardant , arylamine-DOPO-bearing polyphosphoester (PPDSP) has been synthesized and added to the unsaturated polyester (UP). On the one hand, hydrogen bond between arylamine group of PPDSP and UP network enhances the interchain interaction and compatibility. On the other hand, the phosphoester and DOPO groups can generate high-oxidized phosphorus-containing acids at high temperature, which further catalyze the dehydration reaction of arylamine and UP matrix into dense char-layers and exert the synergistic charring effect. By integrating the hydrogen bond and synergistic charring effects into PPDSP macromolecule, the obtained UP/PPDSP resins exhibit excellent fire safety, flame-retardant durability, heat-resistance and impact strength. Compared with UP, the T g and T 5% of UP/PPDSP20 are increased by 11 °C and 20 °C, respectively. The LOI value reaches 27.3%, the UL-94 rating is V-0 and the peak heat release rate is reduced by 58%. Even after one year of normal storage or one week of water soaking, the original flame retardant performance is maintained. Hence, this macromolecular firefighting strategy provides an efficient, durable and green pathway for improving the fire safety of polymers.
Yanlu Sun,Zhengqi Wang,Dequn Wu,Xueli Wang,Jianyong Yu,Ruchao Yuan,Faxue Li
The absence of inherently flame-retardant polyamide 6 (FR-PA6) with enhanced anti-dripping and melt spinnability has significantly limited its further application in textiles. In this work, a binary reactive flame retardant composed of commercial 9,10-dihydro-10-[2,3- di ( hydroxycarbonyl ) propyl ]-10-phosphaphenanthrene-10-oxide (DDP) and synthesized polydiphenylsiloxane (PDPS) was employed to fabricate FR-PA6 through a facile synthetic route. The prepared FR-PA6 containing 5 wt% DDP and 5 wt% PDPS (FR-PA6-5-5) exhibited a UL94 V-0 rating with no melt-droplets during combustion, a 31.0% reduction in heat release rate and a 18.8% decrease in total heat release compared to pure PA6 in cone calorimetric tests. The improved fire safety of FR-PA6-5-5 was contributed to the gas-phase quenching and dilution effect and the condensed-phase barrier effect, which was enhanced by the synergistic charring effect achieved through the formation of P(= O )-O-Si. Additionally, FR-PA6-5-5 exhibited excellent melt spinnability as demonstrated by the successful preparation of filaments with a tensile strength of approximately 2.27 cN/dtex.
危险品化学品经营许可证（带存储）