Of what plastic are Glocks made?

Factual Questions
1

Besides that, how long before the plastic gasses out and becomes brittle? A long time I suppose, since I still see early generation Glock 17s (1990s) in use.

2

Polyamide or nylon 6

3

Technically, it’s “Polymer 2”, a proprietary nylon 6 or nylon 6/6 blend known only to the manufacturer. It’s like the Coke formula. They’re not sharing.
Other polymer firearms are made of Zytel, another nylon 6/6 based thermoplastic owned by DuPont. It should be easier to find information on the DuPont formula than Glock’s.

As for how long they will last? There’s a lot of debate about that. The answer is at least 40 years, since there are still polymer-framed pistols from 40 years ago floating around.
Personally, I think the answer will be measured in lifetimes. It’s not going to degrade faster than you are, that’s for sure.

I am a Glock armorer, but I am certainly not a chemist or polymer engineer. I also used to be a master LE distributor for Glock. So I really only know what they tell me, and what I’ve experienced.

4

Do they add glass beads or fibre to the plastic? That’s typical for nylon that has to be stiff and resist wear from abrasion.

5

I’ve not heard any reference to glass beads, but they specifically state there is no glass fiber. The exclusion of glass fiber is intended to increase cold weather performance.

6

For the non-gun people, keep in mind that entire Glock pistols are not plastic. The barrel, chamber, and most moving parts are metal. On this diagram, part #17 (the frame/grip) and #33 (the magazine case) are the main plastic parts I believe: https://www.eaglegunrangetx.com/wp-content/uploads/2015/10/glocksplode-1.gif

7

I’m just about positive AvE did an episode about a Glock. If he did, he almost certainly would have done his best to figure out what it was made of.
ETA, here’s the episode, I just skipped around looking for the spot where he would mention the material. He said PA66 (Nylon), but didn’t seem 100% sure of himself and guessed it may be a blend with something else in it.
FWIW, he ID it by melting a little with a soldering iron and smelling the fumes that came off it. It’s right around the 20 minute mark.