Silicone oil is routinely used in chemistry labs for exactly what you're
trying to do.  It's more expensive than mineral oil but can be heated to a
much higher temperature without degradation, and it's non-flammable.  You'll
probably want to stir the oil bath to improve heat transfer and temperature
uniformity.  I'm not aware of any compatibility issues between teflon and
silicone oil.

Best regards,

Brian

--
Brian C. Stahl
Graduate Student Researcher
UCSB Materials Research Laboratory
brian.stahl@gmail.com / bstahl@mrl.ucsb.edu
Cell: (805) 748-5839
Office: MRL 3117A


On Wed, Sep 21, 2011 at 12:36 PM, Bhargav Nabar  wrote:

> Hi,
>
> I would like some information about an oil for a heated oil bath. I would
> like to heat an aqueous solution in a sealed teflon container, and would be
> using the oil as a heat transfer medium (in another glass beaker around the
> teflon container). Does anyone here have any experience using oil baths as
> opposed to a water bath. The oil would need to withstand a temperature of
> 125 C maximum, i.e not smoke or boil at this temperature.
>
> Any information would be greatly appreciated.
>
> Thanks in advance.
> Bhargav
> TX, USA