Synthetic fibres -- objective performance ratings?

Hi,

I find myself totally befuddled by the array of synthetic fibres on the market, particularly with regard to how they perform in practise.

• Manufacturers publish breaking strengths, but even there I wonder if they measure by the same criteria -- for example, what is Samson Average Strength as compared with Samson Min Strength?

• Stretch figures are hard to come by in general, and again, I wonder about consistency of measurement. Ditto for creep.

• UV sensitivity -- total minefield! They all say "superior UV resistance", and so forth, but that's meaningless. I want to know how UV-sensitive the fibres are -- is Vectran better/worse than Dyneema? Does PBO really self-destruct after a few months in the Sun? Do the various coatings the manufacturers use (Samthane, Armourcoat, etc.) make much difference?

• Same for chafe!

So, it seems to me that it would not be hard for someone to run objective tests on all this -- eg. set up a rig to pull ropes with weights on the end back and forth over a length of steel wire with UV lamps on them -- but has this ever been done? Is there any real quantitative objective data on how these ropes perform? Failing that, reliable relative data would be a big help -- eg. Vectran is more/less chafe-prone than Spectra, etc.

Cheers, Ian