Trinity flame retardant with benzimidazole structure towards unsaturated polyester possessing high thermal stability, fire-safety and smoke suppression with in-depth insight into the smoke suppression mechanism

Although possessing polymer with excellent flame retardant and low heat release have emerged in previous work, synchronously suppressing smoke (fatal hazards in fire disasters) is still a dilemma. Adjusting the key intermediate-polycyclic aromatic hydrocarbons (PAHs) during the burning processes is a promising path to achieve low smoke release. In this work, we constructed the benzimidazole structure, as an aromatization pre-cursor to chemically modify ammonium polyphosphate (APP) to obtain a trinity flame retardant (APP-BIM). Unsaturated polyester resin (UP), as a typical polymer with high flammability and smoke hazards being the research model, exhibit excellent thermal stability and fire safety compared with previous work. Meanwhile, a homemade smoke sampling module (SSM) coupling with a cone calorimeter (Cone-SSM) is also constructed for online acquiring the soot particles during burning for in-depth investigation of smoke suppression mechanism. This strategy provides a promising new approach to effectively reduce the fire hazard of polymers.

Automated summary

Although flame retardant polymers with low heat release have been developed, suppressing smoke remains a challenge. This study focuses on adjusting key intermediate-polycyclic aromatic hydrocarbons (PAHs) during burning processes to reduce smoke release. By chemically modifying ammonium polyphosphate (APP) with a benzimidazole structure, the trinity flame retardant (APP-BIM) was obtained. The research model, unsaturated polyester resin (UP), exhibited excellent thermal stability and fire safety. Additionally, a homemade smoke sampling module (SSM) coupled with a cone calorimeter (Cone-SSM) was developed for in-depth investigation of smoke suppression mechanism. This strategy offers a promising approach to decrease the fire hazard of polymers.