Investigation of flame-retardant characteristics of a polyaryl ether containing phthalazinone moiety

Abstract

The aerospace, automotive and other industries require very safe specialty engineered plastics that can be used for long times at high temperatures and produce few harmful fumes during combustion in the event of a safety accident, which is essential for protecting personal life and property in a confined environment. The twisted noncoplanar structures give poly (phthalazinone ether) resins excellent temperature resistance and solubility, but clarifying the flame retardancies of the resins is the key to broader application. Herein, a comprehensive comparison has been made between poly (phthalazinone ether) resins and the specialty engineered plastic polysulfone (PSF) based on flame resistance. In vertical burning test, the poly (phthalazinone ether) resin showed a very short flame self-extinguishing time (within 1 s), furthermore, the light transmittance of poly (phthalazinone ether) resin was 100 % at 300 s in the smoke density test, whereas, this value was 10 % for PSF. And the thermal decomposition process and flame retardancy mechanism were investigated by microscale combustion calorimetry, scanning electron microscopy, X-ray photoelectron spectroscopy and thermogravimetric-infrared spectra mass spectrometry. The results indicated that the introduction of phthalazinone moiety not only enhanced the glass transition temperature of the polyaryl ether, but also delayed the smoke generation. This work deepens our understanding of the effects of the molecular structure on the flame retardancy of polyaryl ether resins and provides useful guidance for the design and preparation of polyaryl ether resins with excellent comprehensive properties.