silicone and their application

Silicone polymers structure, prepartion, properties, uses INORGANIC POLYMERS

1. Presented by Sushil Kumar Ranjan M.Sc. (1 st Sem. (Roll No-11 ) Under the guidance of Dr. N.P. Singh Associate professor Department of chemistry, DDU Gorakhpur University, Gorakhpur Silicones and their Applications

2. CONTENT Introduction Nomenclature Manufacturing of silicones Types of silicones Properties of silicones Applications

3. Introduction Silicones, also known as polysiloxanes It is made up by repeating unit of siloxanes, which is chain of alternating silicone atoms and oxygen atoms, combined with carbon, hydrogen or other Silicone fluid, silicone elastomer and silicone resin

4. nomenclature SILICON Si SILICA SILANE SILOXANES X X X X Si -O R R Si O- -O Si O- O O

5. Manufacture of silicone SiO 2 + 2C Si + 2CO Production of silicones takes place in three stage Synthetic of chloro-silanes Hydrolysis of chloro-silanes Condensation polymerization

6. Chlorosilane synthesis xSi + yCH3Cl Cu 300 C MeSiCl 3 Me 3 SiCl Me 2 SiCl 2 Yield (weight %) B.P. ( o C ) >50 10-30 <10 70.0 66.4 57.9

7. Hydrolysis of chlorosilane

8. Condensation polymerization

9. Silicone Family Tree Elastomer Silicone polyether Organo-silicones Silanes Dimethyl compound Fluid Silicone resins Amino silicone

10. Silicone fluid Silicone fluids are linear polysiloxanes of 50-200 units Very low volatility, low surface tension and very good water repellence Silicone fluids are transparent, tasteless and odorless liquids with no known harmful effects. use as transformer oils , lubricants, dielectrics, defoamers and release agents for photocopiers and laser printers. cosmetics, pharmaceuticals and medicine Polydimethylsiloxanes

11. Silicone elastomers Silicone elastomers are long chain polymers made of 6000-600000 siloxanes units. Have high molecular weights. These can be vulcanised to give rubber. Room Temperature Vulcanised (RTV) High temperature vulcanized (HTV) Mold making, electronics, household appliances, machinery and industrial plant engineering, medical applications. Silica filler to enhance strength

12. Silicone resin Water resistance Made by hydrolysis of a blend of chlorosilanes High heat resistance dielectric behaviour is ideal Silicone resins as solvent-based and solvent-free systems, emulsions, but also powders. Typically methyl phenyl silicone Can be flexible or rigid used to make paints and coatings

13. Property of silicone Water repellent Very good thermo-oxidative stability Excellent dielectric properties Low chemical reactivity Low toxicity High thermal stability High gas permeability Low thermal conductivity Resistance to oxygen, ozone and UV light Electrical insulation

14. application of silicone aerospace Cook ware firestops Dry cleaning automotive opthalmology Mold making Personal care

15. lubricant plumbing Coating Building construction toys electronics medicine

16. As modern means of transport become faster, more reliable and more efficient, demands on materials to perform become tougher. As such, smaller parts must resist exposure to extreme heat, moisture, salt and fuels. Most materials deteriorate in these conditions, but not silicones. Silicones retain their properties and – most important – ensure that cars, ships, airplanes and trains operate safely for the long haul.

17. References Industrial chemistry including chemical engineering by BK Sharma, IO-1040 (1991 ) (book.google.co.in) Hans-Heinrich Moretto , Manfred Schulze, Gebhard Wagner (2005) "Silicones" in  Ullmann's Encyclopedia of Industrial Chemistry , Wiley-VCH, Weinheim .  (books.google.co.in) https:// en.wikipedia.org/wiki/Silicone http://www.essentialchemicalindustry.org/polymers/silicones.html

18. Acknowledgement I would like to express my special thanks of gratitude to my teacher Dr. N.P. Singh sir I am also very thankful to the head, Department Of Chemistry D.D.U. Gorakhpur University, Gorakhpur Prof. O.P. Pandey Sir. Secondly, I would also like to thank my parents and friends who helped me a lot in finalizing this presentation within the time frame. Thanks again to all who helped me

19. Thank you