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Some people have health concerns about various acrylics 79.68.139.131 ( talk) 17:39, 24 April 2018 (UTC).
They talk about psuedo-hormones. Does acrylic have any health concerns? Alternatively, can one reference someone claiming they are safe? For example, here is an article implying acrylic is safer than other plastics with bisphenol A.—Preceding unsigned comment added by Dfrankow ( talk • contribs) 22:24, 27 December 2009 (UTC)
The coefficient of thermal exapnsion is listed incorrectly. It is in units of Kelvin, where the referenced source has the same value listed in °C — Preceding unsigned comment added by 130.203.199.112 ( talk) 18:09, 19 June 2017 (UTC)
This seems extremely unlikely, assuming that processing refers to molding, extruding etc. I can't imagine how one might extrude a gas. Surely the processing temperature is in degrees Fahrenheit, not Celsius (i.e. around 125-130 °C )? I have no data, this is only an inference of a typo, so will not edit. 92.24.188.91 ( talk) 01:33, 30 January 2010 (UTC)
Poly(methyl methacrylate) is an amorphous solid, and does not have a melting point. It has a glass transition 105-120 °C, which depends on the synthesis method. Below the glass transition temperature it is a hard clear solid, and above it PMMA is a viscoelastic liquid. Using "melting point" to describe the softening of PMMA is incorrect because "melting point" is a specific type of thermodynamic transition that is not present in PMMA. Perhaps who ever put this in meant the "working temperature" because PMMA could be molded or extruded above its glass transition temperature. 146.6.118.231 ( talk) 22:21, 4 December 2012 (UTC)
Hey you two, play nice. While I think Wizard191 has a valid concern in that the list of trade names is somewhat unwieldy and could use better sourcing, I'd tend to agree with Bachcell that simply mass deleting it isn't the right solution, and certainly adding ~15 {{ fact}} tags to one sentence is WP:POINT-making and does not improve the encyclopedia. — DragonHawk ( talk| hist) 22:58, 13 July 2010 (UTC)
I think I just wandered into a hornet's nest. I just finished revamping the lede section and tried to organize and properly cite the list of trade names for this material. It wasn't easy, but I think I like the way it turned out: I gave just a few of the better-known names in the lede, and then in a later section I itemized these names and added a few others, along with the name of the company with the trademark and a citation— a real citation to a published-in-paper secondary source— for each. Gawd, I hope this doesn't end up poking a stick at the home of the vespines. I really was only trying to improve the article. I think that is what I ended up doing. KDS4444 Talk 05:51, 16 August 2015 (UTC)
This image was added and then removed. (Provided a description is added) is it useful for the article? Materialscientist ( talk) 03:26, 2 August 2010 (UTC)
A poster to this thread claims that roughed-up PMMA is will scintillate with ionizing radiation:
True or false? I'm rather doubtful, but if true, it should be included in the article. JKeck ( talk) 02:41, 15 August 2010 (UTC)
The template now falsely claims that "PMMA" directs to this article. In fact, it should (and once did), but does no more. It directs instead to the DAB page, where there are three items, each of which is far less well known than the plastic. One or the other thing has to go: this template has to be fixed, or the redirect has to be fixed. I can't figure out how to do either one. I would PREFER that the default redirect be changed to here (this article) rather than the dab, and that's it. The present template on this article now would then be left alone since it would THEN be correct. Thanks to anybody who can do the deed, or something that is at least consistent (if you dont want this the primary redirect from PMMA, then can you figure out what template we want?). S B H arris 04:46, 2 December 2010 (UTC)
{{subst:move|PMMA (disambiguation)}} Explanation of your rationale. ~~~~
The sentance "Smooth PMMA surface can be easily nanostructured by treatment in oxygen radio-frequency plasma[34] and nanostructured PMMA surface can be easily smoothed by vacuum ultraviolet (VUV) irradiation.[34]" can be deleted in my opinion. It is common to use it in e-beam lithography and that is an important fact, but the nanostructuration by oxygen-plasma is just a side effect, wich is not common use, or to be more precise: It is common use to clean samples from PMMA by burning the PMMA away with this plasma, if the PMMA is to much crosslinked to be dissolved in Aceton. See: http://iopscience.iop.org/0268-1242/11/8/021 I think that use of PMMA could be much more intersting to be mentioned in the article.-- Do ut des ( talk) 21:49, 14 March 2011 (UTC)
The history of PMMA is incomplete. William Chalmers, who is credited with discovering plexiglas at McGill Univesity, is not mentioned. He should be mentioned as well as his specific contribution. — Preceding unsigned comment added by 8.24.1.220 ( talk) 13:52, 18 March 2013 (UTC)
"PMMA passes infrared light of up to 2800 nm and blocks IR of longer wavelengths up to 25000 nm. Colored PMMA varieties allow specific IR wavelengths to pass while blocking visible light (for remote control or heat sensor applications, for example)." There is no source for transmission in IR. Shalom25 ( talk) 09:44, 20 March 2013 (UTC)
One of the interesting things about PMMA is that it is the lowest cost plastic available in grades transparent well into the UV, so it'd be nice to have more information about this. The article as it stands suggests that there's something unique about these UV-transmitting grades, but it seems that the absorption spectra of the commercial UVT grades are basically the same of those of the pure PMMA samples featured in various scientific articles. Are the UV-transparent grades just... PMMA, and it's rather the the "normal" grades that are modified to block UV, perhaps to prevent yellowing? Does anyone have a source that makes this clear? BoilingLeadBath ( talk) 13:20, 26 March 2024 (UTC)
In section "History" the english article says "The German chemists Wilhelm Rudolph Fittig and _____ Paul discovered in 1877 the polymerization process that turns methyl methacrylate into polymethyl methacrylate." de:Rudolph Fittig#Wissenschaftliches_Werk says that Fittig discovered Methacrylic acid (and gives a source of 1880) and that G. Kahlbaum made PMMA (Plexiglas) from it. Are there any source about who discovered the polymerisation into PMMA? -- Wilhelm-Conrad ( talk) 22:40, 8 April 2013 (UTC)
A major consideration when using PMMA cement is the effect of stress shielding. Since PMMA has a Young's modulus between 1.8 and 3.1 GPa,[31] which is greater than that of natural bone (around 14 GPa for human cortical bone),[32] the stresses are loaded into the cement and so the bone no longer receives the mechanical signals to continue bone remodeling and so resorption will occur
The moduli given do not support stress shielding. 3.1GPa is less stiff than 14GPa. — Preceding unsigned comment added by 65.216.152.2 ( talk) 19:25, 6 November 2013 (UTC)
I can find no evidence for the real first name for the "Paul" fellow who is being cited here as one of the co-discoverers of the 1877 process for making PMMA. And it's kinda weird: Fittig is mentioned repeatedly in searches, and sometimes exclusively, but "Paul" is mentioned only occasionally and never with any kind of first name (this includes searches in paper-printed and published books, the kind of place where you'd expect someone to have done their homework). It almost stinks of a conspiracy of some sort, or of a bad, bad case of parroting of misinformation that goes back to at least 1956 with William John Roff's book "Fibres, plastics, and rubbers: a handbook of common polymers". Since then the mysterious "Paul" has been mentioned-- by last name only-- by Joe Schwartz, Kyung-Sun Lim, Charlotte and Peter Fiell, and Elizabeth Bogle, among others-- these are all big names on the field of plastics and acrylics (though not, apparently, of history or of fact-checking the details). I propose that unless someone can come up with a first name for him, that ______ Paul be removed from this article. KDS4444 Talk 04:02, 3 March 2014 (UTC)
"The full correct name is poly(methyl 2-methylpropenoate). (It is a common mistake to use "an" instead of "en".)" This looks as if it belongs in another article. Going on about the common mistake without explaining how this is preferable to "poly(methyl methacrylate)" is not helpful at all. Not sure what the best solution is, though. Darker than blue ( talk) 07:06, 6 January 2015 (UTC)
PMMA has a number of uses, of which its use in glass-type applications is only one, albeit a large one. For instance, here's a use in fibres: http://www.swicofil.com/products/278polymethylmethacrylate.html and there are also considerable uses of PMMA in inks and coatings. The undue emphasis on sheet PMMA is incomplete and misleading. The disambiguation page admittedly allows for other uses under 'acrylic', but as the sheet material can also be called acrylic, and the polymers used in inks can be called PMMA then we're left with a markedly incomplete article. Gravuritas ( talk) 16:34, 16 April 2015 (UTC)
The list of brand names and Brand owners is minimum partly wrong: e.g. Plexiglas is brand of Evonic. http://www.plexiglas.de/PRODUCT/PLEXIGLAS/EN/Pages/default.aspx Rohm is company from Evonic So crosscheck with http://history.evonik.com/sites/geschichte/en/predecessor-companies/Pages/default.aspx — Preceding unsigned comment added by 195.124.114.36 ( talk) 16:32, 14 December 2015 (UTC)
"Although not a type of familiar silica-based glass, the substance, like many thermoplastics, is often technically classified as a type of glass (in that it is a non-crystalline vitreous substance) hence its occasional historic designation as acrylic "glass". "
This sentence seems to be to be muddled and misconceived. Who considers it to be a vitreous substance ? It has sometimes been called "acrylic glass", because you can make a window pane out of it. Simple. Lathamibird ( talk) 11:31, 11 March 2016 (UTC)
I noticed a few mistakes with the names, including sources going back 10-30 years (industry changes quickly).
I noticed that the captions under the example images throughout the article use different names of PMMA every time, in order: acrylic polymer, acrylic plastic, Perspex, PMMA, Plexiglas, acrylic, Perspex, Plexiglas, acrylic, Lucite, poly(methyl methacrylate).
Either every example in the images is made by a certain (different) brand or manufacturer of PMMA, or this is inconsistency, which would be best resolved by changing every case to (the abbreviation of) the article's title: PMMA.
Casperdewith ( talk) 14:41, 22 March 2019 (UTC)
Transparent glass substitute: Shouldn't it be bomber's transparent nose compartments, not bombardiers, suggests that these nose compartments were produced by Bombardier Aircraft Company — Preceding unsigned comment added by Legotom 14 ( talk • contribs) 12:31, 10 July 2019 (UTC)
I've observed that laser-cut acrylic parts are extremely brittle, especially when they need to flex slightly to interlock, which can make them snap easily. What's the solution to this? Is acrylic normally tougher than this? Is there a better way to laser-cut, or a better material? — Preceding unsigned comment added by 82.8.243.31 ( talk) 03:22, 13 May 2022 (UTC)
Poly(methyl methacrylate) is a polymer of an ester (methyl methacrylate), but it is not a polyester (because the ester part is off to the side, not in the long chain).
The polymer is in some sense an ester; actually many times an ester (once for each -O-CH3 (one on every unit in the chain)), but it is not a polyester. - A876 ( talk) 23:05, 21 October 2022 (UTC)
I have just suppressed the melting temperature (160°C) which has no signification for an amorphous polymer. Glass transition is 46-159°C cf the french page, which is coherent with a process temperature at minimum 160°C, the previous "melting" temperature. However, I do not find how to add a glass transition in this template. Maybe another infobox should be used. - CVS93 ( talk) 14:15, 03 December 2023 (UTC)