The improvement of fire safety performance of flexible polyurethane foam by Highly-efficient P-N-S elemental hybrid synergistic flame retardant

• Published in: Journal of colloid and interface science Vol. 606; pp. 768 - 783
• Main Authors: Zhang, Shenghe, Chu, Fukai, Xu, Zhoumei, Zhou, Yifan, Qiu, Yong, Qian, Lijun, Hu, Yuan, Wang, Bibo, Hu, Weizhao
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 15.01.2022
• Subjects: Flexible polyurethane foam; Phosphorus content; Pyrolysis mechanism; Synergistic flame retardant; Flexible polyurethane foam; Phosphorus content; Synergistic flame retardant; Pyrolysis mechanism
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2021.08.069

[Display omitted] •Three kinds of flame retardant with different phosphorus content were synthesized.•MPBT exerted the best synergistic flame retardant effect.•The dual-phase flame retardant mechanism was analyzed in detail.•Tensile strength of flexible polyurethane foam was improved to a large extent. Herein, three different phosphorus-containing compounds (methyl phosphoryl dichloride, phenyl phosphoryl dichloride and phenyl dichlorophosphate) were reacted with 2-aminobenzothiazole respectively, and a series of synergistic flame retardants with phosphorus, nitrogen and sulfur elements were synthesized, named MPBT, PPBT and POBT respectively. Then, they were added to prepare flame-retardant flexible polyurethane foam (FPUF). Through the analysis of thermal stability, pyrolysis, heat release and smoke release behavior, the influence of different phosphorus-containing structures on the flame-retardant performance of FPUF was studied, and their flame-retardant mechanism was explored in detail. Among them, MPBT had the highest flame retardant efficiency with the same addition amount (10 wt%). The limiting oxygen index (LOI) value of PU/10.0% MPBT reached 22.5 %, and it successfully passed the vertical burning test. Subsequently, the addition amount of MPBT was increased and the best comprehensive performance of flame-retardant FPUF was explored. The results showed that the LOI value of PU/15.0% MPBT was increased to 23.5%. As for PU/15.0% MPBT, the peak heat release rate (PHRR) was 453 KW/m2, which was reduced by 46.64 %; and the flame retardancy index (FRI) value was also increased to 6.88. At the same time, the mechanical properties of flame-retardant FPUF were studied. The tensile strength of PU/15.0% MPBT reached 170 KPa, and the permanent deformation of FPUF/10% MPBT was only 4 %, showing its excellent resilience. The above results show that this phosphorus-containing element hybrid synergistic flame retardant (MPBT) has a very good application prospect in the field of flame-retardant polymer materials.