Design and preparation of silica tube/poly(aryl ether ketone) composites with low dielectric constant

Abstract

Silica tubes with uniform size were designed and prepared by hydrolyzing tetraethyl orthosilicate using D,L-tartaric acid as the self-assembly template. And a novel series of silica tube/poly(aryl ether ketone) composite films were prepared in which silica tubes were covalently bonding onto the side chains of poly(aryl ether ketone) (PAEK-COOH) in the presence of silane coupling agent (γ-aminopropyltriethoxysilane, KH-550). The morphology of the silica tubes was observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The chemical structures of the polymer matrix and composites were confirmed by ¹H NMR and FT-IR spectra. The patterns of wide-angle X-ray diffraction (WAXD) and X-ray photoelectron spectra (XPS) indicated that the silica tubes were incorporated into the PAEK successfully and the homogeneous dispersion of silica tubes in PAEK was illustrated by scanning electron microscopy (SEM). Furthermore, the impact of silica tubes on the properties of composites was investigated in detail. The composite films exhibited low dielectric constants ranging from 2.22 to 2.57 at 1 MHz owing to the introduction of silica tubes, which was found to be distinctly lower than that of the pristine PAEK-COOH film. Meanwhile, these composites still retained excellent thermal and mechanical properties.