Synthesis of multielement phosphazene derivative and the study on flame-retardant properties of epoxy resin. (December 2020)

• Record Type: Journal Article
• Authors: Wang, Lurong; Yang, Baoping; Guo, Yongliang; Zhang, Yabin; Wang, Niannian; Li, Fuchong; Yu, Hailong; Cui, Jinfeng; Guo, Junhong; Mu, Bo; Tian, Li
• Is Part Of: High performance polymers. Volume 32:Number 10(2020)
• Page Start: 1169
• Page End: 1180
• Publication Date: 2020-12
• Subjects: Phosphazene derivative -- flame retardant -- epoxy resin -- flame-retardant properties; Polymerization -- Periodicals; Polymers -- Periodicals; 547.7
• DOI: 10.1177/0954008320937392
• Languages: English
• ISSNs: 0954-0083

Abstract

Herein, we have successfully synthesized phosphorus/nitrogen/silicon tri-elements compound phosphazene derivative hexa-[4-( N -(3-(triethoxysilyl)propyl)acetamide)phenoxy]cyclotriphosphazene (HNTPC) from hexachlorotriphosphazenitrile, methyl 4-hydroxybenzoate, and 3-triethoxysilylpropylamine, and it was used as an additive flame retardant in epoxy resin (EP). Then, the thermal stability and flame retardancy of the composite (HNTPC/EP) were tested. Thermogravimetric analysis showed that the presence of HNTPC made EP matrix decompose at a relatively low temperature, thus promoted the formation of a stable coke layer and protected the matrix from fire. Therefore, the amount of carbon residue was markedly increased at 800°C, indicating an outstanding condensed phase flame-retardant effect. Furthermore, various combustion test data manifested that the addition of HNTPC could significantly improve the flame-retardant performance of EP. In addition, the sample could pass the vertical burning tests (UL-94) V-1 grade when the addition amount was 10% and the limiting oxygen index value was 32.6%, the peak heat release rate and total heat release rate decreased by 40.0% and 21.5%, respectively. Besides, the results of scanning electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy also showed that HNTPC can promote the formation of carbon layer and improved the flame-retardant property of EP. Finally, the condensed phase and gas phase synergistic flame-retardant mechanism of HNTPC was proposed.