From Kraft Pulp Fibers to Si-O-C Ceramics via Sol-Gel Synthesis: Impact of Functionalization and Pre-Pyrolysis

Abstract

This study investigated the fabrication of C/SiO₂ ceramics using kraft pulp fibers (KF) and phosphorylated kraft pulp fibers (PKF) impregnated with a ceramic precursor via a sol-gel route. The rheological behaviour coupled to infrared spectroscopy of the ceramic precursor was examined to optimize the drying process of the impregnated preforms. Thermo-gravimetric analysis and scanning electron microscopy were used to study the thermal behaviour and micro-structure of the ceramics. The PKF exhibited a superior thermal stability, and enhanced fiber/ceramic interactions compared to untreated KF. The impact of the fiber functionalization and of the pre-pyrolysis of PKF on fiber/ceramic interactions was also explored. The in-situ formation of carbon fibers during heat treatment from PKF appears to be a more effective approach for developing future environmentally sustainable ceramic matrix composites (CMCs).