Powered by
TTSReader
Share this page on
Article provided by Wikipedia


Poly(methyl methacrylate)
""PMMA repeating unit.svg
Names
"IUPAC name
Poly(methyl 2-methylpropenoate)
Other names
Poly(methyl methacrylate) (PMMA)
methyl methacrylate resin
Identifiers
3D model ("JSmol)
"ChemSpider
  • none
"ECHA InfoCard 100.112.313
"KEGG
Properties
("C5"O2"H8)n
"Molar mass varies
"Density 1.18 g/cm3[1]
"Melting point 160 °C (320 °F; 433 K)[4]
−9.06×10−6 (SI, 22°C) [2]
1.4905 at 589.3 nm[3]
Except where otherwise noted, data are given for materials in their "standard state (at 25 °C [77 °F], 100 kPa).
N verify ("what is YesYN ?)
"Infobox references
""
""
"Lichtenberg figure: high voltage dielectric breakdown in an acrylic polymer block

Poly(methyl methacrylate) (PMMA), also known as acrylic or acrylic glass as well as by the trade names Crylux, Plexiglas, Acrylite, Lucite, and Perspex among several others (see below), is a "transparent "thermoplastic often used in sheet form as a lightweight or shatter-resistant alternative to "glass. The same material can be used as a casting resin, in inks and coatings, and has many other uses.

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 historical designation as acrylic glass. Chemically, it is the "synthetic polymer of "methyl methacrylate. The material was developed in 1928 in several different laboratories by many chemists, such as William Chalmers, "Otto Röhm, and Walter Bauer, and was first brought to market in 1933 by the "Rohm and Haas Company under the "trademark Plexiglas.

PMMA is an economical alternative to "polycarbonate (PC) when "tensile strength, "flexural strength, "transparency, polishability, and UV tolerance are more important than "impact strength, chemical resistance and heat resistance.[5] Additionally, PMMA does not contain the potentially harmful "bisphenol-A subunits found in polycarbonate. It is often preferred because of its moderate properties, easy handling and processing, and low cost. Non-modified PMMA behaves in a brittle manner when under load, especially under an "impact force, and is more prone to scratching than conventional inorganic glass, but modified PMMA is sometimes able to achieve high scratch and impact resistance.

Contents

History[edit]

The first acrylic acid was created in 1843. "Methacrylic acid, derived from "acrylic acid, was formulated in 1865. The reaction between methacrylic acid and "methanol results in the ester methyl methacrylate. Polymethyl methacrylate was discovered in the early 1930s by British chemists Rowland Hill and John Crawford at Imperial Chemical Industries (ICI) in England. ICI registered the product under the trademark Perspex. About the same time, chemist and industrialist "Otto Röhm of Rohm and Haas AG in Germany attempted to produce safety glass by polymerizing methyl methacrylate between two layers of glass. The polymer separated from the glass as a clear plastic sheet, which Röhm gave the trademarked name Plexiglas in 1933. Both Perspex and Plexiglas were commercialized in the late 1930s. In the United States, E.I. du Pont de Nemours & Company (now DuPont Company) subsequently introduced its own product under the trademark Lucite. In 1936 "Imperial Chemical Industries (now Lucite International) began the first commercially viable production of acrylic safety glass. During World War II both Allied and Axis forces used acrylic glass for submarine periscopes and aircraft windshields, canopies, and gun turrets. Airplane pilots whose eyes were damaged by flying shards of PMMA fared much better than those injured by standard glass, demonstrating better compatibility between human tissue and PMMA than glass.[6] Civilian applications followed after the war.[7]

Names[edit]

Common orthographic stylings include polymethyl methacrylate[8][9] and polymethylmethacrylate. The full chemical name is poly(methyl 2-methylpropenoate). (It is a common mistake to use "an" instead of "en".)

Although PMMA is often called simply "acrylic", "acrylic can also refer to other polymers or copolymers containing "polyacrylonitrile. Notable trade names include Acrylite,[10] Lucite,[11] R-Cast,[12] Plexiglas,[13][14] Optix,[13] Perspex,[13] Oroglas,[15] Altuglas,[16] Cyrolite,[13] and Sumipex.

Synthesis[edit]

PMMA is routinely produced by "emulsion polymerization, "solution polymerization, and "bulk polymerization. Generally, radical initiation is used (including "living polymerization methods), but anionic polymerization of PMMA can also be performed. To produce 1 kg (2.2 lb) of PMMA, about 2 kg (4.4 lb) of "petroleum is needed.["citation needed] PMMA produced by "radical polymerization (all commercial PMMA) is "atactic and completely amorphous.

Processing[edit]

The "glass transition temperature (Tg) of "atactic PMMA is 105 °C (221 °F). The Tg values of commercial grades of PMMA range from 85 to 165 °C (185 to 329 °F); the range is so wide because of the vast number of commercial compositions which are copolymers with co-monomers other than methyl methacrylate. PMMA is thus an organic glass at room temperature; i.e., it is below its Tg. The forming temperature starts at the glass transition temperature and goes up from there.[17] All common molding processes may be used, including "injection molding, "compression molding, and "extrusion. The highest quality PMMA sheets are produced by "cell casting, but in this case, the polymerization and molding steps occur concurrently. The strength of the material is higher than molding grades owing to its extremely high "molecular mass. "Rubber toughening has been used to increase the toughness of PMMA to overcome its brittle behavior in response to applied loads.

Handling, cutting, and joining[edit]

PMMA can be joined using "cyanoacrylate cement (commonly known as "superglue), with heat (welding), or by using solvents such as "di- or "trichloromethane[18] to dissolve the plastic at the joint, which then fuses and sets, forming an almost invisible "weld. Scratches may easily be removed by polishing or by heating the surface of the material.

"Laser cutting may be used to form intricate designs from PMMA sheets. PMMA vaporizes to gaseous compounds (including its monomers) upon laser cutting, so a very clean cut is made, and cutting is performed very easily. However, the pulsed lasercutting introduces high internal stresses along the cut edge, which on exposure to solvents produce undesirable "stress-crazing" at the cut edge and several millimetres deep. Even ammonium-based glass-cleaner and almost everything short of soap-and-water produces similar undesirable crazing, sometimes over the entire surface of the cut parts, at great distances from the stressed edge.[19] Annealing the PMMA sheet/parts is therefore an obligatory post-processing step when intending to chemically bond lasercut parts together.

In the majority of applications, it will not shatter. Rather, it breaks into large dull pieces. Since PMMA is softer and more easily scratched than glass, "scratch-resistant coatings are often added to PMMA sheets to protect it (as well as possible other functions).

Acrylate resin casting[edit]

""
""
Illustrative and secure "bromine chemical sample used for teaching. The glass sample vial of the corrosive and poisonous liquid has been cast into an acrylic plastic cube

"Methyl methacrylate ""synthetic resin" for casting (simply the bulk liquid chemical) may be used in conjunction with a polymerization catalyst such as "MEKP, to produce hardened transparent PMMA in any shape, from a mold. Objects like insects or coins, or even dangerous chemicals in breakable quartz ampules, may be embedded in such "cast" blocks, for display and safe handling.

Properties[edit]

""
""
Skeletal structure of methyl methacrylate, the constituent "monomer of PMMA

PMMA is a strong, tough, and lightweight material. It has a "density of 1.17–1.20 g/cm3,[1][20] which is less than half that of glass.[1] It also has good impact strength, higher than both glass and polystyrene; however, PMMA's impact strength is still significantly lower than polycarbonate and some engineered polymers. PMMA ignites at 460 °C (860 °F) and "burns, forming "carbon dioxide, "water, "carbon monoxide and low-molecular-weight compounds, including "formaldehyde.[21]

PMMA "transmits up to 92% of "visible light (3 mm thickness), and gives a reflection of about 4% from each of its surfaces due to its "refractive index (1.4905 at 589.3 nm).[3] It filters "ultraviolet (UV) light at wavelengths below about 300 "nm (similar to ordinary window glass). Some manufacturers[22] add coatings or additives to PMMA to improve absorption in the 300–400 nm range. PMMA passes "infrared light of up to 2,800 nm and blocks IR of longer "wavelengths up to 25,000 nm. Colored PMMA varieties allow specific IR wavelengths to pass while blocking "visible light (for "remote control or heat sensor applications, for example).

PMMA swells and dissolves in many organic "solvents; it also has poor resistance to many other chemicals due to its easily "hydrolyzed "ester groups. Nevertheless, its environmental stability is superior to most other plastics such as polystyrene and polyethylene, and PMMA is therefore often the material of choice for outdoor applications.[23]

PMMA has a maximum water absorption ratio of 0.3–0.4% by weight.[20] Tensile strength decreases with increased water absorption.[24] Its "coefficient of thermal expansion is relatively high at (5–10)×10−5 °C−1.[25]

Modification of properties[edit]

Pure poly(methyl methacrylate) homopolymer is rarely sold as an end product, since it is not optimized for most applications. Rather, modified formulations with varying amounts of other comonomers, additives, and fillers are created for uses where specific properties are required. For example,

Poly(methyl acrylate)[edit]

The polymer of methyl acrylate, PMA or poly(methyl acrylate), is similar to poly(methyl methacrylate), except for the lack of methyl groups on the backbone carbon chain.[26] PMA is a soft white rubbery material that is softer than PMMA because its long polymer chains are thinner and smoother and can more easily slide past each other.

Uses[edit]

Being transparent and durable, PMMA is a versatile material and has been used in a wide range of fields and applications such as rear-lights and instrument clusters for vehicles, appliances, and lenses for glasses. PMMA in the form of sheets affords to shatter resistant panels for building windows, skylights, bulletproof security barriers, signs & displays, sanitary ware (bathtubs), LCD screens, furniture and many other applications. It is also used for coating polymers based on MMA provides outstanding stability against environmental conditions with reduced emission of VOC. Methacrylate polymers are used extensively in medical and dental applications where purity and stability are critical to performance.["citation needed]

Transparent glass substitute[edit]

""
""
Close-up of pressure sphere of "Bathyscaphe Trieste, with a single conical window of PMMA (Plexiglas) set into sphere hull. The very small black circle (smaller than the man's head) is the inner side of the plastic "window," and is only a few inches in diameter. The larger circular clear black area represents the larger outer-side of the thick one-piece plastic cone "window."
""
""
10-meter (33-foot) deep "Monterey Bay Aquarium tank has acrylic windows up to 33 centimeters (13 inches) thick to withstand the "water pressure

Daylight redirection[edit]

Medical technologies and implants[edit]

In particular, acrylic-type contact lenses are useful for cataract surgery in patients that have recurrent ocular inflammation (uveitis), as acrylic material induce less inflammation.

Artistic and aesthetic uses[edit]

""
""
"Lexus Perspex car sculpture.
""
""
Plexiglas art by "Manfred Kielnhofer
""
""
"Kawai acrylic grand piano

Other uses[edit]

Biodegradation[edit]

""

The "Futuro house was made of fibreglass-reinforced polyester plastic, polyester-polyurethane, and poly(methylmethacrylate); one of them was found to be degrading by "cyanobacteria and "Archaea.[49][50]

See also[edit]

References[edit]

  1. ^ a b c Polymethylmethacrylate (PMMA, Acrylic) Archived 2015-04-02 at the "Wayback Machine.. Makeitfrom.com. Retrieved 2015-03-23.
  2. ^ Wapler, M. C.; Leupold, J.; Dragonu, I.; von Elverfeldt, D.; Zaitsev, M.; Wallrabe, U. (2014). "Magnetic properties of materials for MR engineering, micro-MR and beyond". JMR. 242: 233–242. "doi:10.1016/j.jmr.2014.02.005. 
  3. ^ a b Refractive index and related constants – Poly(methyl methacrylate) (PMMA, Acrylic glass) Archived 2014-11-06 at the "Wayback Machine.. Refractiveindex.info. Retrieved 2014-10-27.
  4. ^ Smith, William F.; Hashemi, Javad (2006). Foundations of Materials Science and Engineering (4th ed.). McGraw-Hill. p. 509. "ISBN "0-07-295358-6. 
  5. ^ Hydrosight. "Acrylic vs. Polycarbonate: A quantitative and qualitative comparison". Archived from the original on 2017-01-19. 
  6. ^ Schwarcz, Joe (6 November 2012), The Right Chemistry: 108 Enlightening, Nutritious, Health-Conscious and Occasionally Bizarre Inquiries into the Science of Daily Life, Doubleday Canada, p. 226, "ISBN "978-0-385-67160-6, archived from the original on 20 April 2016 
  7. ^ "Archived copy". Archived from the original on 2017-10-31. Retrieved 2017-05-22. 
  8. ^ "Elsevier, Dorland's Illustrated Medical Dictionary, Elsevier 
  9. ^ "Merriam-Webster, Merriam-Webster's Collegiate Dictionary, Merriam-Webster 
  10. ^ "The ACRYLITE® brand – ACRYLITE® – Colors, patterns and functions". Acrylite.net. Archived from the original on 2013-10-07. Retrieved 2013-10-05. 
  11. ^ "Trademark Electronic Search System". TESS. US Patent and Trademark Office. p. Search for Registration Number 0350093. Retrieved 29 June 2014. 
  12. ^ "R-Cast® a Brief History". Reynoldspolymer.com. Archived from the original on 2015-09-24. 
  13. ^ a b c d Charles A. Harper; Edward M. Petrie (10 October 2003). Plastics Materials and Processes: A Concise Encyclopedia. John Wiley & Sons. p. 9. "ISBN "978-0-471-45920-0. Archived from the original on 20 April 2016. 
  14. ^ "Archived copy". Archived from the original on 2013-01-21. Retrieved 2013-01-25. 
  15. ^ Reed Business Information (13 June 1974). "Misused materials stoked Sumerland fire". 62 (902). IPC Magazines: 684. "ISSN 0262-4079. Archived from the original on 21 April 2016. 
  16. ^ David K. Platt (1 January 2003). Engineering and High Performance Plastics Market Report: A Rapra Market Report. Smithers Rapra. p. 170. "ISBN "978-1-85957-380-8. Archived from the original on 21 April 2016. 
  17. ^ "Ashby, Michael F. (2005). Materials Selection in Mechanical Design (3rd ed.). Elsevier. p. 519. "ISBN "0-7506-6168-2. 
  18. ^ "Working with Plexiglas" Archived 2015-02-21 at the "Wayback Machine.. science-projects.com.
  19. ^ Andersen, Hans J. "Tensions in acrylics when laser cutting". Archived from the original on 8 December 2015. Retrieved 23 December 2014. 
  20. ^ a b DATA TABLE FOR: Polymers: Commodity Polymers: PMMA Archived 2007-12-13 at the "Wayback Machine.. Matbase.com. Retrieved 2012-05-09.
  21. ^ Zeng, W. R.; Li, S. F.; Chow, W. K. (2002). "Preliminary Studies on Burning Behavior of Polymethylmethacrylate (PMMA)". Journal of Fire Sciences. 20 (4): 297–317. "doi:10.1177/073490402762574749. "INIST:14365060. 
  22. ^ Altuglas International Plexiglas UF-3 UF-4 and UF-5 sheets Archived 2006-11-17 at the "Wayback Machine.. Plexiglas.com. Retrieved 2012-05-09.
  23. ^ Myer Ezrin Plastics Failure Guide: Cause and Prevention Archived 2016-04-21 at the "Wayback Machine., Hanser Verlag, 1996 "ISBN "1-56990-184-8, p. 168
  24. ^ Ishiyama, Chiemi; Yamamoto, Yoshito; Higo, Yakichi (2005). Buchheit, T.; Minor, A.; Spolenak, R.; et al., eds. "Effects of Humidity History on the Tensile Deformation Behaviour of Poly(methyl –methacrylate) (PMMA) Films". MRS Proceedings. 875: O12.7. "doi:10.1557/PROC-875-O12.7 (inactive 2017-01-16). 
  25. ^ "Tangram Technology Ltd. – Polymer Data File – PMMA". Archived from the original on 2010-04-21. 
  26. ^ Polymethyl acrylate and polyethyl acrylate, Encyclopædia Britannica Archived 2007-04-28 at the "Wayback Machine.. Encyclopædia Britannica. Retrieved 2012-05-09.
  27. ^ Kutz, Myer (2002). Handbook of Materials Selection. John Wiley & Sons. p. 341. "ISBN "0-471-35924-6. 
  28. ^ Terry Pepper, Seeing the Light, Illumination Archived 2009-01-23 at the "Wayback Machine.. Terrypepper.com. Retrieved 2012-05-09.
  29. ^ Deplazes, Andrea, ed. (2013). Constructing Architecture – Materials Processes Structures, A Handbook. Birkhäuser. "ISBN "3038214523. 
  30. ^ Yeang, Ken. Light Pipes: An Innovative Design Device for Bringing Natural Daylight and Illumination into Buildings with Deep Floor Plan Archived 2009-03-05 at the "Wayback Machine., Nomination for the Far East Economic Review Asian Innovation Awards 2003
  31. ^ Lighting up your workplace – Queensland student pipes light to your office cubicle Archived 2009-01-05 at the "Wayback Machine., May 9, 2005
  32. ^ Kenneth Yeang Archived 2008-09-25 at the "Wayback Machine., World Cities Summit 2008, June 23–25, 2008, Singapore
  33. ^ Gerchikov, Victor; Mossman, Michele; Whitehead, Lorne (2005). "Modeling Attenuation versus Length in Practical Light Guides". LEUKOS. 1 (4): 47–59. "doi:10.1582/LEUKOS.01.04.003 (inactive 2017-01-16). 
  34. ^ How Serraglaze works Archived 2009-03-05 at the "Wayback Machine.. Bendinglight.co.uk. Retrieved 2012-05-09.
  35. ^ Glaze of light Archived 2009-01-10 at the "Wayback Machine., Building Design Online, June 8, 2007
  36. ^ Robert A. Meyers, "Molecular biology and biotechnology: a comprehensive desk reference", Wiley-VCH, 1995, p. 722 "ISBN "1-56081-925-1
  37. ^ Apple, David J (2006). Sir Harold Ridely and His Fight for Sight: He Changed the World So That We May Better See It. Thorofare NJ USA: Slack. "ISBN "1-55642-786-7. 
  38. ^ Kaufmann, Timothy J.; Jensen, Mary E.; Ford, Gabriele; Gill, Lena L.; Marx, William F.; Kallmes, David F. (2002-04-01). "Cardiovascular Effects of Polymethylmethacrylate Use in Percutaneous Vertebroplasty". American Journal of Neuroradiology. 23 (4): 601–4. "PMID 11950651. 
  39. ^ "Filling in Wrinkles Safely". U.S. Food and Drug Administration. February 28, 2015. Archived from the original on 21 November 2015. Retrieved 8 December 2015. 
  40. ^ de Swart, Ursula. My Life with Jan. Collection of Jock de Swart, Durango, CO
  41. ^ Plexiglas ® Color Numbers Archived 2016-05-18 at the Portuguese Web Archive. professionalplastics.com
  42. ^ Syurik, Julia; Jacucci, Gianni; Onelli, Olimpia D.; Holscher, Hendrik; Vignolini, Silvia (22 February 2018). "Bio-inspired Highly Scattering Networks via Polymer Phase Separation". Advanced Functional Materials. "doi:10.1002/adfm.201706901. 
  43. ^ Goodman, Robert L. (2002-11-19). How Electronic Things Work... And What to do When They Don't. McGraw Hill Professional. "ISBN "9780071429245. 
  44. ^ "Duarte, F. J. (Ed.), Tunable Laser Applications (CRC, New York, 2009) Chapters 3 and 4.
  45. ^ a b Lapshin, R. V.; Alekhin, A. P.; Kirilenko, A. G.; Odintsov, S. L.; Krotkov, V. A. (2010). "Vacuum ultraviolet smoothing of nanometer-scale asperities of Poly(methyl methacrylate) surface". Journal of Surface Investigation. X-ray, Synchrotron and Neutron Techniques. 4 (1): 1–11. "doi:10.1134/S1027451010010015. 
  46. ^ – Blacklight Tattoo Ink – Blacklight Tattoo Ink FAQ Archived 2012-01-04 at the "Wayback Machine.. Crazychameleonbodyartsupply.com. Retrieved 2012-05-09.
  47. ^ Uhl, Alexander R.; Romanyuk, Yaroslav E.; Tiwari, Ayodhya N. (2011). "Thin film Cu(In,Ga)Se2 solar cells processed from solution pastes with polymethyl methacrylate binder". Thin Solid Films. 519 (21): 7259–63. "Bibcode:2011TSF...519.7259U. "doi:10.1016/j.tsf.2011.01.136. 
  48. ^ JS2K-PLT Archived 2007-09-28 at the "Wayback Machine.. Ibanezregister.com. Retrieved 2012-05-09.
  49. ^ Cappitelli, Francesca; Principi, Pamela; Sorlini, Claudia (2006). "Biodeterioration of modern materials in contemporary collections: Can biotechnology help?". Trends in Biotechnology. 24 (8): 350–4. "doi:10.1016/j.tibtech.2006.06.001. "PMID 16782219. 
  50. ^ Rinaldi, Andrea (2006). "Saving a fragile legacy. Biotechnology and microbiology are increasingly used to preserve and restore the world's cultural heritage". EMBO Reports. 7 (11): 1075–9. "doi:10.1038/sj.embor.7400844. "PMC 1679785Freely accessible. "PMID 17077862. 

External link[edit]

Perspex Technical Properties https://www.theplasticshop.co.uk/plastic_technical_data_sheets/perspex_technical_properties_data_sheet.pdf

) ) WikipediaAudio is not affiliated with Wikipedia or the WikiMedia Foundation.