Back in the 1950s I remember that the only "modern" bowstring fiber was Browning B36, a "Dacron" polyester fiber that happily replaced linen bowstrings. The number "36" represents the tensile strength per strand, 36 pounds. A few years pass and Browning ups the tensile strength and then B42 comes on the market. Years later is the emergence of their B50, which was THE staple bowstring fiber until Kevlar came along - and boy did that stuff kill more bows that it was worth and become the sole bowstring fiber to avoid at all costs. Enter then Browning's polypropylene "Fast Flight" and then THAT was the string fiber to use as long as the bow limb tips were reinforced. Suffice to say, initially FF killed some bows, too, but that was the fault of the bow's owner by using that fiber on a bow that had weak limb tips, and was not the string fiber's fault. Much later on BCY entered the bowstring fiber market with B500 and then what's become pretty much the staple today for all polyester bowstrings, B55.
Cruising around the web for Dacron (polyester) string fibers and I can find Browning B50 and BCY B55, and one more - Flex Archery "Dacrogen" which is touted as a 100% polyester (Dacron) and "safe for all bows". Sold on a spool that's got about 273 yards versus the 1450 yards for B50 or B55, and a price tag that's 30% higher. Hmm, thank you, but I'll pass and stick with B55.
So it's fair to say that any bowstring fiber other than the three above will be HMPE polypropylene based, which includes SO many brand model names such as Fast Flight, Dynaflight 97, D'02, 452x, 8125, Fury, Mercury, Force 10, X99, 454, 652, Xcel, Majesty, ASB, Majesty Pro, Majesty 777, and more.