Synthesis and ceramic conversion of novel silazane modified phenol formaldehyde resin

Novel silazane modified phenol formaldehyde (SPF) resins were synthesized by reacting varying amounts of 1, 3, 5-trimethyl-1', 3', 5'-trivinylcyclotrisilazane (CTS) with phenol formaldehyde (PF) resin. For the selection of an appropriate pyrolysis condition, polymer-to-ceramic conversion of SPF was carried out at 1450 °C and 1650 °C under argon and nitrogen atmosphere. The pyrolysis conditions significantly affected the evolution of ceramic phases, excess carbon and morphology which were thoroughly investigated through XRD, Raman and FESEM techniques. This study establishes silazane modified phenol formaldehyde as a new class of preceramic polymer for high-temperature applications. The study also reveals that nitrogen atmosphere is a more suitable gas atmosphere than argon atmosphere for preparation of desired C/Si3N4/SiC ceramics with higher ceramic yield.