Talk:Polyurethane

Carpet underlayment

165.139.171.10 edited this page by adding the "carpet underlayment" bit. 165.139.171.10 21:27, 6 February 2004 (UTC)

I will try to get some of my friends in the industry to contribute here. It will be useful to us since we want to consider this form of knowledge capture for our work space also.

How about Linear Polyurethane

As an avid sailor, I've used LP to paint several boats, but as of 2006-05-30, there is no mention of it in Wikipedia at all. I'd like to know how linear polyurethane differs from polyurethane. Also suggest adding its use as a paint-like coating, whether in a separate article linked from this one, or just in a subsection of this article.

I suspect that linear polyurethane uses a diol with a di-isocyanate to give linear polymer molecules, while other polyurethanes use a triol to give a cross-linked molecular structure. --GCarty 17:37, 30 March 2007 (UTC)

This article...

This article is TERRIBLE!!!!. Is anyone monitoring this who knows anything about PU in general? (yes, I am going to start cpc) I guess not. Foam. More Foam, and did I mention Foam? PU foam by CO2. No other way is commercial, {There are many forms other than foam, but foam does dominate the volume of product produced}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! {It may be unfortunate, but URETHANES has been choosen by the industry for the general class of polymers. We can't change this. Subclasses are called polyether urethanes and another subclass are ... urea-urethanes. The general class is found under urethanes, probably for historical reasons 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. 208.230.167.50 16:40, 10 June 2005 (UTC)

Thanks for acknowledging the problem, and posing some constructive suggestions. I had the same emotional response to the hideous state of martensite when I first saw it, but you'll notice that the talk page of that article is free of my yelling at the prior editors who had contributed similar sophomoric, misleading half-truths to the ones you have enumerated here. Be bold and make some of these much-needed improvements, once you've calmed down a bit. Feel free to use this template:

==Uses==

===Coatings===
Basic overview

{{sect-stub}}

===Adhesives and sealants===

===Elastomers===

===[[Engineering plastic]]s===

Also, sign your rants with tildes (~~~~). Anonymous criticism may be less likely to be taken as constructive. Civility helps sometimes, too.

Cheers, The wise fool who thought poly(urethane-co-urea) was accurate

Polyparadigm 17:13, 10 June 2005 (UTC)

Inventor

Also it must say that it was invented by Otto Bayer in 1937 - Germany. 200.30.252.51 22:21, 9 October 2005 (UTC)

This article needs to become "well rounded"

No hazards of polyurethane are listed. This whole article looks like it was borrowed from somewhere on the net! 24.131.5.144 21:36, 16 December 2005 (UTC)

Hear, hear! Where is the information on health impacts?!

I'm told it's sometimes implanted into the human body. Since there hasn't been a controversy smilar to the one over silicone, perhaps it's not all that hazardous...though I'm sure the free monomers aren't very good for you.--Joel 01:54, 19 August 2007 (UTC)

Removing wikify template

I'm removing the wikify template because it doesn't apply here. What the article needs is expansion, restructuring and support from references. Alan Pascoe 23:10, 20 February 2006 (UTC)

Urethanes versus "urethane"

The use of the term "urethane" for polyurethane resins has probably lead to mis-reporting of this substance to the USEPA under the Toxics Release Inventory (TRI). Urethane, ethyl carbamate, is a probable human carcinogen - polyurethanes are not. They are not listed as a TRI substance, either. Therefore, this clarification should help those required to submit TRI reports and those that need to interpret them. Oldsci 23:08, 12 May 2006 (UTC)

aquatic uses

Somewhere in the back of my head is the thought that PU foam is used to core watercraft because it will not absorb water, unlike balsa. But I could not find an appropriate wiki template to cite "the back of my head". So if someone could confirm that and expand the watercraft section, thanks.--J Clear 02:04, 16 June 2006 (UTC)

It seems pretty absorbant when I spill coffee on my chair cushions. The reason it's used probably has more to do with manufacturing: you can just build a form, and pour the mix in, rather than trying to carve a big piece of wood and then build something around it.--Joel 01:57, 19 August 2007 (UTC)

polystyrene composites?

Does anyone know if canned polyurethane filler can be used on polystyrene, or is it likely to dissolve the polystyrene? T boyd 09:19, 25 March 2007 (UTC)

Chemistry Section

I am interested to know if someone is putting together a chemistry section for this article. If the importance of this article is high, I feel that it is relevant to discuss the chemistry, the raw materials and the formulating of polyurethane systems separate from the production of finished goods.

P Cottontail 03:07, 16 April 2007 (UTC)

I've started the section on Chemistry. My intention is to discuss the chemistry, raw materials, and some formulating principles that are used to produce polyurethane polymers. I think some of what is in the Production section should be moved here, and that section revised to focus on the actual manufacturing/production process used to make finished goods.

P Cottontail 04:06, 21 April 2007 (UTC)

Can somebody please explain "urethane links" to a layperson? I was trying to learn the difference between urethane and polyurethane and I came across this idea of urethane links. Mattsonm 00:28, 19 August 2007 (UTC)

Used for high-performance Bushings and Mounts

I'm surprised to see that this article doesn't mention the use of polyurethane in high-performance bushings and mounts. It's a common material in almost every high-performance automotive aftermarket suspension bushing and motor or transmission mount, and is a very popular upgrade amongst enthusiasts. Does anyone else feel like this should be added?

--Ioeth 21:48, 20 June 2007 (UTC)

As a matter of fact, I just noticed that the bushings article even mentions polyurethane as a material used to make them --Ioeth 21:51, 20 June 2007 (UTC)

I feel that from an encyclopedic article standpoint, it makes more sense to refer to polyurethanes from the bushings article as a material specifically used in their manufacture; and that the polyurethane article refer to bushings in a more general fashion. For example, stating polyurethanes are "used in the manufacture of high performance microcellular and elastomeric materials, such as bushings, dampers, tire compounds, die cutting pads", et cetera. Taking a broader view, the Uses section of the polyurethane article needs to be re-written this way. That is, polyurethane refers to general classes of material such as foams, elastomers, adhesives, sealants, and coatings, which are used to manufacture Items A, B, and C; and that the articles for Items A, B and C refer back to polyurethane as a material specific to their manufacture. Best Regards. P Cottontail 05:06, 27 June 2007 (UTC)

Polyurethane Rigid Foam

[[User:Big Swede|15:26, 11 June, 2007 (PDT)

Polyurethane foams are also used extensively in structural and process-related applications. High-density expanded urethane foam products (10-lb per cubic foot up to 50-lb per cubic foot) can be used as tooling substrates, and as materials for visual styling exercises, composite lay-up tools, vacuum-forming tools, and for construction of mold-patterns.

Rigid, high-density polyurethane foam cores (6 lb to 24-lb per cubic-foot density)can be found in various marine applications (boat transoms, bulkheads, decks, stringers, and hatch covers, used in combination with polyester-resins and fiberglass.

Special forms of rigid polyurethane foam having hydro-static pressure resistance have been used to provide flotation or neutral buoyancy for robot submersibles and for International Space Station components in test-assembly at NASA. These foams are capable of withstanding up to 350 psi hydrostatic pressure, making them useful to water depths up to 600 feet.

They are also used (in their 18-20-lb density flame-retardant forms) in aircraft interior stow-bins, class-divider panels, and in sidewall-panel detail parts when processed with aircraft-grade composite prepregs and linings.

Rigid, medium-density polyurethane foams have been used in explosive-blast mitigation, where the cellular-structure of the foam provides a disruption to the propagation of explosive-blast shock waves through air. The energy absorbed by the crushing of these foams under blast-wave pressure, or the gas-pressure wave that follows an explosion, is considerable and has yet to be fully exploited in practice.

Rigid, high-density polyurethane foams with flame-retardant and intumescing additives are used in the construction of containment packages for nuclear and other hazardous-waste transport containers. These vessels are designed to absorb hi-G impacts and then withstand 2300-degree fuel pool-fire conditions while keeping the contents inside at temperatures below the boiling-point of water. Polyurethane foams are the materials of choice for these applications, replacing wood blocks and other more inconsistent and flammable materials.

Flexible, flame-retardant integral-skin expanded polyurethane foams are used in aircraft flight-deck applications for head-strike protection. Similar polyurethane foams have been used as comfort-padding and as part of the man-machine interface in man-portable anti-tank weapons, and military electronic-surveillance devices where a person may be in intimate contact with the instrument for long periods of time.

Molded rigid polyurethane foams are used as packaging materials in submunition-carrying weapons systems. They have also been used to create non-lethal "flash-bang" grenades, as well as stand-off devices for shaped-charge cutting systems for aircraft-ejection egress, and for detaching rocket motor nozzles from Space Shuttle SRBs.

High-density rigid foams (30-lb and higher) have been successfully employed as wood-replacement products in the construction of frozen-food warehouse structures. The foam, in block-form, is placed under roof columns between the column-base and the concrete footing, providing a thermal-break. This practice keeps cold inside the building, preventing freezing the soil around support structures. Wood materials used in these applications in the past were prone to rot and structural collapse, as well as water-uptake, limiting the lifespan of these warehouse structures while allowing the loss of considerable energy through the roof-columns.

Big Swede 22:31, 11 July 2007 (UTC)Big Swede

Soy Oil polyols

In regards to the entry in the History section; the manufacture of polyols from soy oil as a "green" or an "environmentally friendly" process has been, in the United States at least, driven by soy bean growers and adjunct processors. Typical of the marketing campaign is the CompositesWorld article cited in the main article. I think the efficacy of soy oil polyols is overstated. A competing vegetable oil polyol is neat castor oil, which has been used to manufacture polyurethane products since at least 1974, see US Patent 3,959,573; or search the USPTO for "polyurethane castor oil" or "polyurethane" AND "castor oil". Castor oil, because of its high ricinoleic acid triglyceride content (about 90%), is a natural triol and requires little or no post processing to be used as a polyol. On the other hand, soybean oil has no hydroxyl content and must be post-processed to be used as a polyol. Poignant is the fact that the US accounts for about 1/3 of the world production of soybeans. India, on the other hand, is the primary global producer of castor oil. See the Wikipedia article on castor oil for comparative US domestic pricing, which is probably the real driving force behind the use of soy oil derived polyols.

P Cottontail 02:32, 14 August 2007 (UTC)