Ned Simmons wrote in
:

On Wed, 7 Sep 2011 01:47:42 +0000 (UTC), David Lesher
wrote:

Ned Simmons writes:

What's this stuff normally used for? (would have guessed rollers or
some chemically resistant app so I am thrown by the electrical grade
mention)


PTFE also has some desirable electrical properties,

It's used up to the GHz range....not just power frequencies.

The lot that the teflon came in also included a smaller amount of this
more unusual stuff:
http://www.rexolite.com/list.html#WHAT

I do microwave circuit design, and we use Rexolite a fair amount. It's
basically polystyrene, but they have to make it using a special process.
The stabilizer chemical used for regular polystyrene is very lossy. I
think it's also more heavily cross linked than typical polystyrene. It
machines quite well, and doesn't melt as easily as the normal stuff.

The stabilizeer is really critical if you want to store or ship the
styrene monomer material. Once it starts cross-linking, it's exothermic.
The hotter it gets, the faster it cross-links, and you get a run-away
reaction which can easily end up in a fire. Dow chemical had a huge tank
of it that took off on them a number of years ago.

Doug White