Aren't climbing slings just Dyneema webbing?
They are made with Nylon I think, not ideal-too stretchy and heavy.
I made some straps from Vectran core webbing last year and have been testing them since- see HF link. http://www.hammockforums.net/forum/showthread.php?t=17385&highlight=vectran+straps
They are still working great, showing no sign of wear after at least 50 nights.