Polymers that aren't brittle at the cryogenic temperatures found on Titan? For entertainment purposes, I'm imagining a colony on a non-terraformed Titan, and wondering what is achievable. Hydrocarbons are incredibly plentiful there, while metals and even silicon would be extremely rare and precious, which makes me think that polymers would be used to an even greater extent than on Earth in nearly every form of engineering.
On Titan, the pressure is around $\pu{1.5 atmospheres}$ and the surface temperature is cryogenic at $\pu{76 K}$ on average. This makes me imagine that they would want to use a lot of polymers with extremely low glass transition temperatures (below and around $\pu{76 K}$ at $\pu{1.5 atmospheres}$), so as to have rubbery and non-brittle materials that work outdoors.
Do we know of such materials, and if not, are they physically plausible? I didn't see any examples in tables of glass transition temperatures that I found on the internet, but then again, such polymers would have a lot less application on Earth, if they even exist as solids here.
Of course, these cryogenic temperatures only apply to things that go outside, like suits, vehicles, extraction and construction equipment, buildings, and the necessary pumps and other equipment needed for life support.
According to NASA1 the main factor inhibiting the widespread use of polymer materials in space environments is oxygen erosion, the materials tested so far to be proven effective in space are  Teflon, Mylar, Kapton and Tedlar.
Further experimentation is being conducted on board ISS according to their website2.
I do not believe there are polymers currently capable of handing the cold, pressure, and oxygen erosion of Titan, as such, the probe3 Huygens sent to Titan was constructed of aluminum coated Kapton, which seems to be the industry standard for space environments.
References:

https://www.nasa.gov/centers/glenn/shuttlestation/station/misse.html
http://www.spacestationresearch.com/tag/polymer-erosion-and-contamination-experiment-polymers/
https://en.wikipedia.org/wiki/Huygens_(spacecraft)