[longhair]

 
Hopefully someone can help me.

I am looking for the results of what would happen if dimethylpolysiloxane were subjeted to a combustion reaction.  Here's why;

I have converted my diesel engine car to run on waste vegetable oil (see greasecar.com).  The oil currently availbale is almost always mixed with this compound as an anti-foaming agent.  I do not want to burn this compound with my oil until I can discover 1) what byproducts will be produced ie what this will add to the emissions from my vehicle. 2) what damage might be done to the combustion chamber of the vehicle.

Anyone with ANY input would be considered a god in my book.  OK maybe that's a little strong, but I will definitely appreciate the info.

Thanks
longhair

[Dude]

Simple heating of polydimethylsiloxane (PDMS) tends to create cyclic rings.  I would be a bit concerned about combusting PDMS.  There is a good chance of reacting all the way to silicon dioxide (i.e. sand).  That would be a hard particulate and might be postulated to cause some gouging on the metal surfaces in the engine.  I am not aware of any formal studies, however, of the use of PDMS as a fuel or fuel additive.