Re: I am looking for a reference of the thermodynamic properties of elastomers

Dear David,
Your material will almost certainly get hard at liquid nitrogen
temperatures.  I have machined teflon by keeping a bottle of liquid
nitrogen next to a lathe and pouring a little bit over the piece when it
warmed up too much.  This worked quite nicely.  If you want some technical
information on the properties of elastomers vs. temperature there is a
detailed discussion in the Parker O-Ring Handbook (chapter A-3).

I hope this helps,

Larry