Flame-Retardant Materials Based on Phosphorus-Containing Polyhedral Oligomeric Silsesquioxane and Bismaleimide/Diallylbisphenol A with Improved Thermal Resistance and Dielectric Properties

摘要

Polyhedral oligomeric silsesquioxane containing 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DP) was used to flame-retard 4,4-bismaleimidophenyl methane (BDM)/2,2-dially bisphenol A (DBA) resins, and the integrated properties of the resins were investigated. The fire resistance of BDM/DBA resins containing DP was analyzed by limiting oxygen index (LOI) and vertical burning (UL94) tests. The results show that DP increased the LOI of the resins from 25.3 to 38.5%. The BDM/DBA resins were evaluated to have a UL-94 V-1 rating, which did not satisfy the high standards of industry. On the other hand, BDM/DBA containing DP achieved a UL-94 V-0 rating. The thermal stability and char formation were studied by thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy. TGA and scanning electron microscopy-energy-dispersive X-ray spectrometry measurements demonstrated that the DP resulted in an increase in the char yield and the formation of the thermally stable carbonaceous char. The results of Raman spectroscopy showed that the DP enhanced the graphitization degree of the resin during combustion. Moreover, the modified BDM/DBA resins exhibited improved dielectric properties. Specifically, the dielectric constant and loss at 1 MHz of the BDM/DBA/15% DP resin were 3.11 and 0.008, respectively, only about 93 and 73% of those of the BDM/DBA resin. All of the investigations showed that DP was an effective additive for developing high-performance resins with attractive flame-retardant and dielectric properties. (c) 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41545.