Abstract
Inorganic and organometallic polymers capable of giving high ceramic residue (more than 50 wt%) on heat treatment in an inert atmosphere are called “preceramic polymers.” As they are polymeric in nature, processing techniques used for conventional polymer processing can be easily adopted. They can be applied as coating, cast into film and drawn into fiber and then converted into corresponding ceramic material. Amorphous materials that are thermally stable to very high temperatures with compositions not obtainable with common synthetic methods can be obtained from preceramic polymers. Kinetic stabilization of less stable phases, adaptability of various fabrication capabilities of polymer process engineering, formation of nanoceramics of desired composition, pressureless sintering, and machinability are the main advantages of obtaining ceramics from polymeric precursors.
Polymer-derived ceramics find applications as oxidation resistant high temperature ceramic materials in the form of fiber, coatings and adhesives, and matrix of ceramic matrix composites for use by aerospace, nuclear, and defense establishments. In addition, they are also being investigated for end-use in biomedical devices, drug delivery systems, water remediation, energy storage devices, microelectronics, and nanosensors.
The present chapter deals with synthesis, characterization, and ceramic conversion of silicon-based preceramic polymers, and ceramics from carbonaceous polymers, and their possible space applications. In view of the voluminous literature, equal emphasis could not be given to many of the developments in the area of preceramic polymers and the discussion is confined to relevant systems which have the scope for space applications.