13^th International Conference on Advanced Materials and Nanotechnology October 26-28, 2017 Osaka, Japan

S. Packirisamy obtained his PhD from Indian Institute of Technology, Kharagpur in 1982. He initiated the work on polymer-deived ceramics in the Vikram Sarabhai Space Centre, Indian Space Research Organization in 1986 and continued to contribute in this area until his superannuation in 2015 as Deputy Director. He was UNESCO Fellow, Tokyo Institute of Technology, Tokyo (1982-83), Research Associate, Case Western Reserve University, Cleveland (1993) and Visiting Scientist, Michigan Molecular Institute, Midland (1994). Presently, he is Professor in Chemistry, Sharda University, Greater Noida, India. He has to his credit 14 patents, 45 publications in international journals and 4 book chapters, and guided 8 PhD scholars and 15 post-graduate theses. Presenting author

Inorganic and organometallic polymers capable of giving ceramics in good yield (at least 50%) when subjected to pyrolysis are referred to as “preceramic polymers”. There are several advantages in using preceramic polymers for obtaining ceramics. Using conventional ceramic processing techniques it is difficult to get non-oxide ceramic coatings, continuous ceramic fibres and ceramic films. Preceramic polymers can be processed using conventional polymer processing techniques into coatings, films, fibres and composites followed by pyrolysis and sintering to get ceramic coatings, ceramic films, ceramic fibres and ceramic matrix composites (CMCs). Unlike the conventional ceramic processing routes, preceramic route invariably give nanoceramics and hence, it is easy to machine polymer-derived ceramic components.Yet another advantage is that conversion of polymers to ceramics takes place at relatively low temperatures (1200-1500°C) when compared to conventional processes (~2000°C).Keeping in view of the potential space applications, the research work on polymer-derived ceramics was initiated in the Space Centre in 1987 and over the years, different types of preceramic polymers such as polycarbosilanes, polysialhydrocarbons, polyborosiloxanes, and poly(metalloborosiloxane)s have been synthesized and their conversion to ceramics have been studied. These precursors have been evaluated for the following space applications: i) oxidation resistant coatings for C/C composites for renetry and reusable launch vehicles, ii) matrix resins for ceramic matrix composites and lightweight ceramics, candidate materials for advanced thermostructural/thermal protection materials for reusable launch vehicles, iii) thermal barrier coatings, iv) ceramic adhesives and v) atomic oxygen resistant coatings for low earth orbit space structures. This keynote lecture covers the above aspects.