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This is really cool :) Thought, look into nanocellulose fibers for textiles, and your product could be biodegradable while still exceptionally strong[1]. Tech

• kathomuth 9y ago
  Interesting! Thanks so much for sharing. Another fiber I'm keeping an eye on is Spider silk, but that tech is still too immature for mass production.
• twic 9y ago
  Polylactones are biodegradable polymers available right now, although i don't think they're particularly strong: https://en.wikipedia.org/wiki/Polycaprolactone https://en.wikipedia.org/wiki/Polycaprolactone If the fibers can be made cheaply and are biodegradable, then perhaps you could make deliberately and responsibly disposable tights, in which case their strength wouldn't matter as much. It's not as cool as super-strong hosiery, but thinking about it, i quite like the idea of disposable underwear!
  • kragen 9y ago
    Polycaprolactone is actually unbelievably strong in one particular way: its fracture toughness is astounding because its elongation at break is usually over 1000%, higher even than polyethylenes. No other structural material even comes close, unless you're counting soft rubbers (latex, polyurethane, or SEBS, but not silicones), which reach high deformations through pseudoelasticity rather than plastic flow. Unfortunately, PCL's tensile strength is kind of lame, tens of megapascals, like typical polyethylenes — but polyethylenes greatly exceed it in chemical resistance, heat resistance, and moldability. And its low tensile modulus gives it a very low speed of sound, which in turn means that in some applications where you'd really love its incredible fracture toughness, the impacts are sharp enough that it will break anyway. So, most of the time, you're better off with metals or stronger engineering plastics for fracture toughness. However, the poor moldability and low glass transition point of PCL give it a rather unique property among reasonably stiff materials: you can shape the freaking stuff with your hands while molten. And so it is that you can find PCL inexpensively on Amazon under names like ShapeLock, InstaMorph, ThermoMorph, Kemilove, TechTack, Polymorph, and so on. Just be careful about the service temperature. Like most plastics and metals, PCL loses most of its strength well before it actually melts. As for textiles, supposing you could spin PCL into fibers (which I'm pretty sure you can, even if nobody has), PCL tights would be pretty much impossible to get runs in, but they would melt if you spilled hot coffee on them. That might be a deal-killer. Rayon (cellophane) is also biodegradable. Usually this is considered a drawback. Polylactide is probably the most popular biodegradable plastic going around these days, but it isn't really biodegradable, it's aquadegradable. And it's probably too brittle to make a useful garment fiber, even if the hydrolysis problem wasn't a killer.
    • kathomuth 9y ago
      Very interesting! This is a fiber we hadn't looked into, seems like there would be some challenges with our use case (particularly the melting point). But definitely something I'm going to look more into.
      • kragen 9y ago
        Drop US$20 on a few hundred grams on Amazon and play with it. I used it to fix a lot of things when I was traveling around with my wife in a Volkswagen bus, even though the temperatures sometimes got too high for it.
        • kathomuth 9y ago
          Will do!
    • HarryHirsch 9y ago
      Someone must have looked into ester/amide copolymers already, anyone would think that that increased the melting point.