In the old car example, one would wonder what the role of ultraviolet light and heat, possibly very high, may play. From what I read, UV is more harmful to plastics than just oxygen.
BTW, that was not my claim, but the claim posted here:
"Are my bases “dry” when they become gray and hairy?
NO! Bases become gray and hairy when they have become “abraided” from snow crystals. Bases are plastic and snow is sandpaper. When the amount of skiing you do exceeds the amount you’re waxing, you get gray hairy bases. Petroleum distillate bases do not oxidize! A brand new pair of skis on the rack from 20 years ago will have as dark and rich a base as it does today. Oxygen does not eat plastic, friction does!"
Your comment about oxidation makes me wonder is some ptex makers put more or less antioxidant chemical in the formula. I just looked at a old pair of Salomon Pockets that have not been waxed since 2012 and have been sitting in the garage. The black base is black....no white on them.
Antioxidants for plastics:
Help prevent "oxidation", the polymer reacting with oxygen. Oxidation can cause loss of impact strength, elongation, surface cracks and discolouration. Antioxidants help prevent thermal oxidation reactions when plastics are processed at high temperatures and light-assisted oxidation when plastics are exposed to UV light."
An interesting article from 1968 on the aging of polyethylene plastic. It would be interesting to find something more recent on UHMWPE or even HDPE.
Edited by GorgeSkier - 2/24/14 at 6:20pm