Amino-functionalized carbon nanotubes/polyphosphazene hybrids for improving the fire safety and mechanical properties of epoxy
Mutian Zhou, Desen Zeng, Shuilai Qiu, Xia Zhou, Liang Cheng, Zhoumei Xu, Weiyi Xing, Yuan Hu
Abstract
To expand further modern industrial applications of epoxy resin (EP), the urgent problems of flammability and poor mechanical properties have to be solved. Therefore, amino-functionalized carbon nanotubes ([email protected]) was designed and successfully synthesized to enhance the comprehensive properties, including fire safety and mechanical properties. Especially, the flame retardant mechanism, the combustion and pyrolysis process of EP/[email protected] were investigated as well. With the addition of 1.5 wt% [email protected], the peak heat release rate (PHRR) and total heat release (THR) of EP were reduced by 27.6% and 29.0%, respectively, which may due to the cooperative effect between the phosphorus-nitrogen synergistic flame retardant of polyphosphazene and the cohesive phase flame retardant of carbon nanotubes. In addition, the mechanical performance of EP/[email protected] composites were also investigated. The results showed that the impact strength, tensile strength and the storage modulus effectively increased by 65.0%, 29.0% and 13.2%, respectively. Meanwhile, the change of the combustion and pyrolysis process of EP/[email protected] may be attributed to the catalytic effect of the amino-functionalized polyphosphazene, which could participate in the formation of epoxy thermal curing crosslinking network and catalyze the degradation process of epoxy resin.