# How do metalloids, cermets and metal matrix composites reflect light?

**URL:** <https://boards.straightdope.com/t/how-do-metalloids-cermets-and-metal-matrix-composites-reflect-light/740465>\
**Category:** Factual Questions\
**Created:** [December 14, 2015, 11:06pm UTC](https://boards.straightdope.com/t/how-do-metalloids-cermets-and-metal-matrix-composites-reflect-light/740465 "2015-12-14T23:06:04Z")\
**Posts on this page:** 2\
**Page:** 2

<div class="post-metadata">

**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\
**Post date:** [December 16, 2015, 12:18pm UTC](https://boards.straightdope.com/t/how-do-metalloids-cermets-and-metal-matrix-composites-reflect-light/740465/21 "2015-12-16T12:18:11Z")

</div>

> [@Napier](#):
>
> Teflon is a duPont trademark for ptfe, pfa, and fep at least.
> 
> Yes, different along versus across chain, and no single crystal big pieces. Don’t know about polychlorotrifluoroethylene. How crystalline is that?

AFAIK, “Teflon:” without modifiers is just PTFE. Non-PTFE “Teflon” and filled TEflons have extra letters after the name, like TEFLON-AF or TEFLON-FEP.

I don’t know how crystalline PCTFE is. As I say, how transpasr5ent it is depends upon its processing. It could be that the transparent stuff is highly crystalline.

---

<div class="post-metadata">

**Author:** ![Napier](https://avatars.discourse-cdn.com/v4/letter/n/ce73a5/32.png) [@Napier](https://boards.straightdope.com/u/Napier)\
**Post date:** [December 17, 2015, 3:32am UTC](https://boards.straightdope.com/t/how-do-metalloids-cermets-and-metal-matrix-composites-reflect-light/740465/22 "2015-12-17T03:32:03Z")

</div>

> [@CalMeacham](#):
>
> AFAIK, “Teflon:” without modifiers is just PTFE. Non-PTFE “Teflon” and filled TEflons have extra letters after the name, like TEFLON-AF or TEFLON-FEP.
> 
> I don’t know how crystalline PCTFE is. As I say, how transpasr5ent it is depends upon its processing. It could be that the transparent stuff is highly crystalline.

[http://www2.dupont.com/Teflon\_Industrial/en\_US/assets/downloads/k15758.pdf](http://www2.dupont.com/Teflon_Industrial/en_US/assets/downloads/k15758.pdf)

Here’s duPont literature for Teflon perfluoroalkoxy resin (PFA), no PTFE at all. The trademark is for a line of fluropolymers. Yes, they also sell filled PTFE under that trademark, too.

[Previous page](https://boards.straightdope.com/t/how-do-metalloids-cermets-and-metal-matrix-composites-reflect-light/740465.md?page=1)