Cyclotriphosphazene nanofber‑reinforced polybenzoxazine/epoxy nanocomposites for low dielectric and fame‑retardant applications

Abstract
In the present work, a halogen-free fame-retardant cyclotriphosphazene nanofber�reinforced polybenzoxazine/epoxy (PBZ/EP/PZT) hybrid nanocomposites have been developed and characterized. Initially, equimolar quantities of benzoxazine and the
epoxy matrix is blended and varying weight percentages (0, 0.5, 1.0 and 1.5 wt%) of PZT nanofber are reinforced to obtain hybrid nanocomposites. It was observed that PBZ/EP/PZT nanocomposites possess higher values of glass transition temperatures
(Tg—208 °C) and displayed enhanced thermal stability with high char yields than those of neat matrix. The fammability characteristics of the nanocomposites were studied on the basis of the LOI, UL-94 burning experiments as well as the analy�sis of residual chars of the tested bars after burning. The V-0 classifcation for the
nanocomposites indicates that the incorporation of PZT nanofber (1.5 wt%) imparts enhanced fame retardancy to the PBZ/EP matrix. The dielectric properties of these nanocomposites have been studied at 1 MHz over the temperature range between
30 and 200 °C. Data resulted from thermal, fame-retardant and dielectric studies indicate that the composite materials can be considered as the potential candidate for thermally stable fre and heat resistant, dielectric sealants, and encapsulants in electronic applications