Talk:Polyurethane

165.139.171.10 edited this page by adding the "carpet underlayment" bit.

This article is TERRIBLE!!!!. Is anyone monitoring this who knows anything about PU in general? I guess not. Foam. More Foam, and did I mention Foam? PU foam by CO2. No other way is commercial, I guess? Not! Guys and gals, you've got several industries; of which, I'll admit, Foam is the largest (last I heard). I've not seen the breakdown on what categories PU is used in. Help is needed! Here's my take 1) Coatings, Adhesives and Sealants 2) Elastomers 3)Engineering Plastics (rigid to semi-rigid). OR 1) (belts, gaskets, bearings, wheels) 3) Coatings (sealants and adhesives, too) 3) Foam 4) Medical ... To the wise one who thinks that something with a molecular formula of ~80(ether/ester links)+2(urethane links)+1(urea link) should be named poly(urethane-co-urea), I say think again! If you're going to get technical, then do it right! To the wise one who claimed urethanes don't penetrate wood, I say hog wash! Urethanes are used on high traffic wood surfaces all the time. They're some of the best field applied wood adhesives that exist. I guess you all are right in not mentioning the word "isocyanate" - since virtually all (but not quite) polyurethanes are made (produced) from them. And for the learned one who mentions not using them on antiques, I say 1) future restoration is made impossible (or very difficult) and 2) they are prone to discoloration and UV degradation (both aliphatic and especially aromatic isocyanate based) - this combination is a no brainer! you AVOID them cuz in 100 years they will need to be redone and you may destroy the antique trying to get them off! Their STRENGTH is their versatility; they range from soft enough to sleep on to hard enough to drive on. Their performance can be easily customized to meet the application. Alcohol, polyester, isocyanate, adhesion, polarity, hard segment-soft segment (block), abrasion, RIM, all are concepts (among others) that this article lacks and should (IMHO) cover. Not to mention the fact that PU's are really misnamed. I'd say start over.