Synthesis of an organic-inorganic hybrid strontium hydroxystannate nanorod and application as novel flame retardant

A novel sulfonyldiphenol-containing polyphosphazene derivative (PZS) wrapped strontium hydroxystannate (PZS-SrSn(OH)6) nanorods with rich N, P, Sr, Sn elements was prepared and used as an efficient flame retardant. PZS-SrSn(OH)6 exhibited high flame retardant efficiency and smoke suppression to the epoxy (EP) composites. Compared with EP, under merely 3% of addition of PZS-SrSn(OH)6 nanorods, the LOI value was increased to 29.6% from 26.2%. Furthermore, the combustion properties of treated EP were assessed by cone calorimeter (CONE) and it demonstrated that the EP/PZS-SrSn(OH)6 obtained better flame retardancy which was confirmed by the reduction of heat release rate (HRR) and total smoke release (TSR). The peak HRR values and TSR for EP/PZS-SrSn(OH)6 were reduced by 30.2% and 23.1%, respectively. It was confirmed that the core/shell structured PZS-SrSn(OH)6 could significantly enhance the synergistic effect between PZS and SrSn(OH)6, and thereby resulting higher flame retardant efficiency.