Thermal properties and combustion behaviors of a novel UV-curable flame retarded coating containing silicon and phosphorus

A silicon-based acrylate (SHEA) was synthesized via the reaction between 2-hydroxylethyl acrylate and dimethyldichlorosilane, and characterized by Fourier transform infrared (FTIR), 1H NMR spectroscopy and 29Si NMR spectroscopy. The SHEA was blended with phosphorus-containing tri(acryloyloxyethyl) phosphate (TAEP) at different ratios to obtain a series of UV-curable flame retarded resins. The final unsaturation conversion of the SHEA films was determined by FTIR. Their combustion behaviors were examined by microscale combustion calorimetry (MCC). The thermal degradations of TAEP/SHEA composites were characterized using thermogravimetric analysis/infrared spectrometry (TG-IR). The MCC results present that the addition of TAEP into SHEA was able to decrease the HRR, HRC, Tmax and THC. Among the TAEP/SHEA resins, Si1 (TAEP:SHEA is 1:1) owns the highest initial decomposition temperature and leaves the most char residue at 800 °C. The change of chemical structure during the thermal degradation process was monitored by real-time FTIR analysis to study the condensed-phase flame retarded mechanism.