Novel in situ-foaming materials derived from a naphthalene-based poly(arylene ether ketone) containing thermally labile groups

Abstract

A novel in situ-foaming material was successfully prepared by a naphthalene-based hydroxyl-containing poly(arylene ether ketone) (PAEK) modified with thermally labile tert-butyloxycarbonyl which can decompose and in situ generate CO₂ and isobutene as the foaming agents. The structure and thermal properties of the polymers were characterized by using ¹H NMR spectra and thermogravimetry coupled time-resolved mass spectrogram (TG/MS). The resulting polymers exhibited relatively high T_g because of the existence of a rigid naphthalene moiety. Then closed microcellular porous membranes with a wide range of expansion ratio (ER) were obtained by a simple thermal treatment from 140 °C to 280 °C for 60 seconds, without using any other physical or chemical foaming agents. The highest ER was 53.98%. This method has never been reported before on high-performance poly(aryl ether) materials. Furthermore, we investigated the relationship between the foaming temperature and the morphology of membranes in detail by using density measurement and scanning electron microscopy (SEM).