Poly(methyl methacrylate)

Poly(methyl methacrylate) (PMMA), also known as acrylic, acrylic glass, or plexiglass as well as by the trade names Crylux, Plexiglas, Acrylite, Lucite, Perclax 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 German Röhm & Haas AG (as of January 2019 part of Evonik Industries) and its partner and former U.S. affiliate Rohm and Haas Company under the trademark Plexiglas.[5]

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.[6] 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.

Poly(methyl methacrylate)
PMMA repeating unit
Names
IUPAC name
Poly(methyl 2-methylpropenoate)
Other names
Poly(methyl methacrylate) (PMMA)
methyl methacrylate resin
perspex
Identifiers
3D model (JSmol)
ChemSpider
  • none
ECHA InfoCard 100.112.313
KEGG
Properties
(C5O2H8)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).
Lichtenberg figure in block of Plexiglas
Lichtenberg figure: high voltage dielectric breakdown in an acrylic polymer block

History

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 ICI Acrylics (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.[7] Civilian applications followed after the war.[8]

Names

Common orthographic stylings include polymethyl methacrylate[9][10] and polymethylmethacrylate. The full IUPAC 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,[11] Lucite,[12] PerClax, R-Cast,[13] Plexiglas,[14][15] Optix,[14] Perspex,[14] Oroglas,[16] Altuglas,[17] Cyrolite,[14] and Sumipex.

Synthesis

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. PMMA produced by radical polymerization (all commercial PMMA) is atactic and completely amorphous.

Processing

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.[18] 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

PMMA can be joined using cyanoacrylate cement (commonly known as superglue), with heat (welding), or by using chlorinated solvents such as dichloromethane or trichloromethane[19] (chloroform) 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.[20] 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

Bromine vial in acrylic cube
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 methyl ethyl ketone peroxide (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

Methyl-methacrylate-skeletal
Skeletal structure of methyl methacrylate, the constituent monomer of PMMA
Perspex pieces (AM 2007.10.2-2)
Pieces of perspex the windscreen of a German plane shot down during World War II

PMMA is a strong, tough, and lightweight material. It has a density of 1.17–1.20 g/cm3,[1][21] 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.[22]

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[23] 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.[24]

PMMA has a maximum water absorption ratio of 0.3–0.4% by weight.[21] Tensile strength decreases with increased water absorption.[25] Its coefficient of thermal expansion is relatively high at (5–10)×10−5 °C−1.[26]

Modification of properties

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,

  • A small amount of acrylate comonomers are routinely used in PMMA grades destined for heat processing, since this stabilizes the polymer to depolymerization ("unzipping") during processing.
  • Comonomers such as butyl acrylate are often added to improve impact strength.
  • Comonomers such as methacrylic acid can be added to increase the glass transition temperature of the polymer for higher temperature use such as in lighting applications.
  • Plasticizers may be added to improve processing properties, lower the glass transition temperature, or improve impact properties.
  • Dyes may be added to give color for decorative applications, or to protect against (or filter) UV light.
  • Fillers may be added to improve cost-effectiveness.

Poly(methyl acrylate)

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.[27] 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

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.

Transparent glass substitute

Bathyscaphe Trieste sphere
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."
KelpAquarium
10-meter (33-foot) deep Monterey Bay Aquarium tank has acrylic windows up to 33 centimeters (13 inches) thick to withstand the water pressure
  • PMMA is commonly used for constructing residential and commercial aquariums. Designers started building large aquariums when poly(methyl methacrylate) could be used. It is less often used in other building types due to incidents such as the Summerland disaster.
  • PMMA is used for viewing ports and even complete pressure hulls of submersibles, such as the Alicia submarine's viewing sphere and the window of the bathyscaphe Trieste.
  • PMMA is used in the lenses of exterior lights of automobiles.[28]
  • Spectator protection in ice hockey rinks is made from PMMA.
  • Historically, PMMA was an important improvement in the design of aircraft windows, making possible such designs as the bombardier's transparent nose compartment in the Boeing B-17 Flying Fortress. Modern aircraft transparencies often use stretched acrylic plies.
  • Police vehicles for riot control often have the regular glass replaced with PMMA to protect the occupants from thrown objects.
  • PMMA is an important material in the making of certain lighthouse lenses.[29]
  • PMMA was used for the roofing of the compound in the Olympic Park for the 1972 Summer Olympics in Munich. It enabled a light and translucent construction of the structure.[30]
  • PMMA (under the brand name "Lucite") was used for the ceiling of the Houston Astrodome.

Daylight redirection

  • Laser cut acrylic panels have been used to redirect sunlight into a light pipe or tubular skylight and, from there, to spread it into a room.[31] Their developers Veronica Garcia Hansen, Ken Yeang, and Ian Edmonds were awarded the Far East Economic Review Innovation Award in bronze for this technology in 2003.[32][33]
  • Attenuation being quite strong for distances over one meter (more than 90% intensity loss for a 3000 K source[34]), acrylic broadband light guides are then dedicated mostly to decorative uses.
  • Pairs of acrylic sheets with a layer of microreplicated prisms between the sheets can have reflective and refractive properties that let them redirect part of incoming sunlight in dependence on its angle of incidence. Such panels act as miniature light shelves. Such panels have been commercialized for purposes of daylighting, to be used as a window or a canopy such that sunlight descending from the sky is directed to the ceiling or into the room rather than to the floor. This can lead to a higher illumination of the back part of a room, in particular when combined with a white ceiling, while having a slight impact on the view to the outside compared to normal glazing.[35][36]

Medical technologies and implants

  • PMMA has a good degree of compatibility with human tissue, and it is used in the manufacture of rigid intraocular lenses which are implanted in the eye when the original lens has been removed in the treatment of cataracts. This compatibility was discovered by the English ophthalmologist Sir Harold Ridley in WWII RAF pilots, whose eyes had been riddled with PMMA splinters coming from the side windows of their Supermarine Spitfire fighters – the plastic scarcely caused any rejection, compared to glass splinters coming from aircraft such as the Hawker Hurricane.[37] Ridley had a lens manufactured by the Rayner company (Brighton & Hove, East Sussex) made from Perspex polymerised by ICI. On 29 November 1949 at St Thomas' Hospital, London, Ridley implanted the first intraocular lens at St Thomas's Hospital in London.[38]

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

  • Eyeglass lenses are commonly made from PMMA.
  • Historically, hard contact lenses were frequently made of this material. Soft contact lenses are often made of a related polymer, where acrylate monomers containing one or more hydroxyl groups make them hydrophilic.
  • In orthopedic surgery, PMMA bone cement is used to affix implants and to remodel lost bone. It is supplied as a powder with liquid methyl methacrylate (MMA). Although PMMA is biologically compatible, MMA is considered to be an irritant and a possible carcinogen. PMMA has also been linked to cardiopulmonary events in the operating room due to hypotension.[39] Bone cement acts like a grout and not so much like a glue in arthroplasty. Although sticky, it does not bond to either the bone or the implant, it primarily fills the spaces between the prosthesis and the bone preventing motion. A disadvantage of this bone cement is that it heats up to 82.5 °C (180.5 °F) while setting that may cause thermal necrosis of neighboring tissue. A careful balance of initiators and monomers is needed to reduce the rate of polymerization, and thus the heat generated.
  • In cosmetic surgery, tiny PMMA microspheres suspended in some biological fluid are injected as a soft tissue filler under the skin to reduce wrinkles or scars permanently.[40] PMMA as a soft tissue filler was widely used in the beginning of the century to restore volume in patients with HIV-related facial wasting. PMMA is used illegally to shape muscles by some bodybuilders.
  • Plombage is an outdated treatment of tuberculosis where the pleural space around an infected lung was filled with PMMA balls, in order to compress and collapse the affected lung.
  • Emerging biotechnology and Biomedical research uses PMMA to create microfluidic lab-on-a-chip devices, which require 100 micrometre-wide geometries for routing liquids. These small geometries are amenable to using PMMA in a biochip fabrication process and offers moderate biocompatibility.
  • Bioprocess chromatography columns use cast acrylic tubes as an alternative to glass and stainless steel. These are pressure rated and satisfy stringent requirements of materials for biocompatibility, toxicity and extractables.

Uses in dentistry

Due to its aforementioned biocompatibility, Poly(methyl methacrylate) is a commonly used material in modern dentistry, particularly in the fabrication of dental prosthetics, artificial teeth, and orthodontic appliances.

  • Acrylic Prosthetic Construction: Pre-polymerized, powdered PMMA spheres are mixed with a Methyl Methacrylate liquid monomer, Benzoyl Peroxide (initiator), and NN-Dimethyl-P-Toluidine (accelerator), and placed under heat and pressure to produce a hardened polymerized PMMA structure. Through the use of injection molding techniques, wax based designs with artificial teeth set in predetermined positions built on gypsum stone models of patients' mouths can be converted into functional prosthetics used to replace missing dentition. PMMA polymer and methyl methacrylate monomer mix is then injected into a flask containing a gypsum mold of the previously designed prosthesis, and placed under heat to initiate polymerization process. Pressure is used during the curing process to minimize polymerization shrinkage, ensuring an accurate fit of the prosthesis. Though other methods of polymerizing PMMA for prosthetic fabrication exist, such as chemical and microwave resin activation, the previously described heat-activated resin polymerization technique is the most commonly used due to its cost effectiveness and minimal polymerization shrinkage.
  • Artificial Teeth: While denture teeth can be made of several different materials, PMMA is a material of choice for the manufacturing of artificial teeth used in dental prosthetics. Mechanical properties of the material allow for heightened control of aesthetics, easy surface adjustments, decreased risk of fracture when in function in the oral cavity, and minimal wear against opposing teeth. Additionally, since the bases of dental prosthetics are often constructed using PMMA, adherence of PMMA denture teeth to PMMA denture bases is unparalleled, leading to the construction of a strong and durable prosthetic.[41]

Artistic and aesthetic uses

Lexus LF-A Crystallised Wind
Lexus Perspex car sculpture.
Maylan-interior-design-neue-wiener-werkstaette-interlux-roehm- evonik- indeustries-contemporary-light-art-sedan-chair-seats-manfred-kielnhofer-illumination-auchtion
Plexiglas art by Manfred Kielnhofer
Kawai CR-40A
Kawai acrylic grand piano
  • Acrylic paint essentially consists of PMMA suspended in water; however since PMMA is hydrophobic, a substance with both hydrophobic and hydrophilic groups needs to be added to facilitate the suspension.
  • Modern furniture makers, especially in the 1960s and 1970s, seeking to give their products a space age aesthetic, incorporated Lucite and other PMMA products into their designs, especially office chairs. Many other products (for example, guitars) are sometimes made with acrylic glass to make the commonly opaque objects translucent.
  • Perspex has been used as a surface to paint on, for example by Salvador Dalí.
  • Diasec is a process which uses acrylic glass as a substitute for normal glass in picture frames. This is done for its relatively low cost, light weight, shatter-resistance, aesthetics and because it can be ordered in larger sizes than standard picture framing glass.
  • As early as 1939, Los Angeles-based Dutch sculptor Jan De Swart experimented with samples of Lucite sent to him by DuPont; De Swart created tools to work the Lucite for sculpture and mixed chemicals to bring about certain effects of color and refraction[42]
  • From approximately the 1960s onward, sculptors and glass artists such as Jan Kubíček, Leroy Lamis, and Frederick Hart began using acrylics, especially taking advantage of the material's flexibility, light weight, cost and its capacity to refract and filter light.
  • In the 1950s and 1960s, Lucite was an extremely popular material for jewelry, with several companies specialized in creating high-quality pieces from this material. Lucite beads and ornaments are still sold by jewelry suppliers.
  • Acrylic Sheets are produced in dozens of standard colors,[43] most commonly sold using color numbers developed by Rohm & Haas in the 1950s.

Other uses

  • PMMA, in the commercial form Tecnovit 7200 is used vastly in the medical field. It is used for plastic histology, electron micropsy, as well as many more uses.
  • PMMA has been used to create ultra-white opaque membranes that are flexible and switch appearance to transparent when wet.[44]
  • Acrylic is used in tanning beds as the transparent surface that separates the occupant from the tanning bulbs while tanning. The type of acrylic used in tanning beds is most often formulated from a special type of polymethyl methacrylate, a compound that allows the passage of ultraviolet rays
  • Sheets of PMMA are commonly used in the sign industry to make flat cut out letters in thicknesses typically varying from 3 to 25 millimeters (0.1 to 1.0 in). These letters may be used alone to represent a company's name and/or logo, or they may be a component of illuminated channel letters. Acrylic is also used extensively throughout the sign industry as a component of wall signs where it may be a backplate, painted on the surface or the backside, a faceplate with additional raised lettering or even photographic images printed directly to it, or a spacer to separate sign components.
  • PMMA was used in Laserdisc optical media.[45] (CDs and DVDs use both acrylic and polycarbonate for impact resistance.)
  • It is used as a light guide for the backlights in TFT-LCDs.
  • Plastic optical fiber used for short distance communication is made from PMMA, and perfluorinated PMMA, clad with fluorinated PMMA, in situations where its flexibility and cheaper installation costs outweigh its poor heat tolerance and higher attenuation over glass fiber.
  • PMMA, in a purified form, is used as the matrix in laser dye-doped organic solid-state gain media for tunable solid state dye lasers.[46]
  • In semiconductor research and industry, PMMA aids as a resist in the electron beam lithography process. A solution consisting of the polymer in a solvent is used to spin coat silicon and other semiconducting and semi-insulating wafers with a thin film. Patterns on this can be made by an electron beam (using an electron microscope), deep UV light (shorter wavelength than the standard photolithography process), or X-rays. Exposure to these creates chain scission or (de-cross-linking) within the PMMA, allowing for the selective removal of exposed areas by a chemical developer, making it a positive photoresist. PMMA's advantage is that it allows for extremely high resolution patterns to be made. Smooth PMMA surface can be easily nanostructured by treatment in oxygen radio-frequency plasma[47] and nanostructured PMMA surface can be easily smoothed by vacuum ultraviolet (VUV) irradiation.[47]
  • PMMA is used as a shield to stop beta radiation emitted from radioisotopes.
  • Small strips of PMMA are used as dosimeter devices during the Gamma Irradiation process. The optical properties of PMMA change as the gamma dose increases, and can be measured with a spectrophotometer.
  • A blacklight-reactive tattoo ink using PMMA microcapsules has been developed.[48]
  • PMMA can be used as a dispersant for ceramic powders to stabilize colloidal suspensions in non-aqueous media. Due to its high viscosity upon dissolution, it can also be used as binder material for solution deposition processes, e.g. printing of solar cells.[49]
  • In the 1960s, luthier Dan Armstrong developed a line of electric guitars and basses whose bodies were made completely of acrylic. These instruments were marketed under the Ampeg brand. Ibanez[50] and B.C. Rich have also made acrylic guitars.
  • Ludwig-Musser makes a line of acrylic drums called Vistalites, well known as being used by Led Zeppelin drummer John Bonham.
  • Artificial nails in the "acrylic" type often include PMMA powder.[51]
  • Some modern briar, and occasionally meerschaum, tobacco pipes sport stems made of Lucite.
  • PMMA technology is utilized in roofing and waterproofing applications. By incorporating a polyester fleece sandwiched between two layers of catalyst-activated PMMA resin, a fully reinforced liquid membrane is created in situ.
  • PMMA is a widely used material to create deal toys and financial tombstones.
Acrylic Heels

High heel shoes made of Lucite

Basscat Bass

An electric bass guitar made from poly(methyl methacrylate)

Biodegradation

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.[52][53]

See also

References

  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 (2014): 233–242. arXiv:1403.4760. Bibcode:2014JMagR.242..233W. doi:10.1016/j.jmr.2014.02.005. PMID 24705364.
  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 978-0-07-295358-9.
  5. ^ Plexiglas history by Evonik (German only)
  6. ^ Hydrosight. "Acrylic vs. Polycarbonate: A quantitative and qualitative comparison". Archived from the original on 2017-01-19.
  7. ^ 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
  8. ^ "Polymethyl methacrylate | chemical compound". Archived from the original on 2017-10-31. Retrieved 2017-05-22.
  9. ^ "polymethyl methacrylate", Dorland's Illustrated Medical Dictionary, Elsevier
  10. ^ "Polymethyl methacrylate". Merriam-Webster Dictionary.
  11. ^ "Acrylite Online Shop | Cut-to-Size | Sheets | Rods | Tubes". Acrylite.co. Archived from the original on 2013-10-07. Retrieved 2018-11-15.
  12. ^ "Trademark Electronic Search System". TESS. US Patent and Trademark Office. p. Search for Registration Number 0350093. Retrieved 29 June 2014.
  13. ^ "R-Cast® a Brief History". Reynoldspolymer.com. Archived from the original on 2015-09-24.
  14. ^ 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.
  15. ^ "WIPO Global Brand Database". Archived from the original on 2013-01-21. Retrieved 2013-01-25.
  16. ^ 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. Cite journal requires |journal= (help)
  17. ^ 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.
  18. ^ Ashby, Michael F. (2005). Materials Selection in Mechanical Design (3rd ed.). Elsevier. p. 519. ISBN 978-0-7506-6168-3.
  19. ^ "Working with Plexiglas" Archived 2015-02-21 at the Wayback Machine. science-projects.com.
  20. ^ Andersen, Hans J. "Tensions in acrylics when laser cutting". Archived from the original on 8 December 2015. Retrieved 23 December 2014.
  21. ^ a b DATA TABLE FOR: Polymers: Commodity Polymers: PMMA Archived 2007-12-13 at the Wayback Machine. Matbase.com. Retrieved 2012-05-09.
  22. ^ 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. hdl:10397/31946. INIST:14365060.
  23. ^ 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.
  24. ^ 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
  25. ^ 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.
  26. ^ "Tangram Technology Ltd. – Polymer Data File – PMMA". Archived from the original on 2010-04-21.
  27. ^ Polymethyl acrylate and polyethyl acrylate, Encyclopædia Britannica Archived 2007-04-28 at the Wayback Machine. Encyclopædia Britannica. Retrieved 2012-05-09.
  28. ^ Kutz, Myer (2002). Handbook of Materials Selection. John Wiley & Sons. p. 341. ISBN 978-0-471-35924-1.
  29. ^ Terry Pepper, Seeing the Light, Illumination Archived 2009-01-23 at the Wayback Machine. Terrypepper.com. Retrieved 2012-05-09.
  30. ^ Deplazes, Andrea, ed. (2013). Constructing Architecture – Materials Processes Structures, A Handbook. Birkhäuser. ISBN 978-3038214526.
  31. ^ 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
  32. ^ Lighting up your workplace – Queensland student pipes light to your office cubicle Archived 2009-01-05 at the Wayback Machine, May 9, 2005
  33. ^ Kenneth Yeang Archived 2008-09-25 at the Wayback Machine, World Cities Summit 2008, June 23–25, 2008, Singapore
  34. ^ 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 2019-08-20).
  35. ^ How Serraglaze works Archived 2009-03-05 at the Wayback Machine. Bendinglight.co.uk. Retrieved 2012-05-09.
  36. ^ Glaze of light Archived 2009-01-10 at the Wayback Machine, Building Design Online, June 8, 2007
  37. ^ Robert A. Meyers, "Molecular biology and biotechnology: a comprehensive desk reference", Wiley-VCH, 1995, p. 722 ISBN 1-56081-925-1
  38. ^ 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 978-1-55642-786-2.
  39. ^ 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.
  40. ^ "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.
  41. ^ Prosthodontic treatment for edentulous patients : complete dentures and implant-supported prostheses. Zarb, George A. (George Albert), 1938- (13th ed.). St. Louis, Mo.: Elsevier Mosby. 2013. ISBN 9780323078443. OCLC 773020864.CS1 maint: others (link)
  42. ^ de Swart, Ursula. My Life with Jan. Collection of Jock de Swart, Durango, CO
  43. ^ Plexiglas ® Color Numbers Archived 2016-05-18 at the Portuguese Web Archive. professionalplastics.com
  44. ^ 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. 28 (24): 1706901. doi:10.1002/adfm.201706901.
  45. ^ Goodman, Robert L. (2002-11-19). How Electronic Things Work... And What to do When They Don't. McGraw Hill Professional. ISBN 9780071429245.
  46. ^ Duarte, F. J. (Ed.), Tunable Laser Applications (CRC, New York, 2009) Chapters 3 and 4.
  47. ^ 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.
  48. ^ – Blacklight Tattoo Ink – Blacklight Tattoo Ink FAQ Archived 2012-01-04 at the Wayback Machine. Crazychameleonbodyartsupply.com. Retrieved 2012-05-09.
  49. ^ 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.
  50. ^ JS2K-PLT Archived 2007-09-28 at the Wayback Machine. Ibanezregister.com. Retrieved 2012-05-09.
  51. ^ Symington, Jan (2006). "Salon management". Australian nail technology. Croydon, Victoria, Australia: Tertiary Press. p. 11. ISBN 978-0864585981.
  52. ^ 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.
  53. ^ 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 1679785. PMID 17077862.

External links

Cast acrylic

Cast Acrylic is a form of poly(methyl methacrylate) (PMMA). It is formed by casting the monomer, methyl methacrylate, mixed with initiators and possibly other additives into a form or mold. Sheet and rod stock are generated by casting into static forms, while tubing is done in rotational molds.

Cell casting

Cell casting is a method used for creating poly(methyl methacrylate) (PMMA) sheets. Liquid monomer is poured between two flat sheets of toughened glass sealed with a rubber gasket and heated for polymerization. Because the glass sheets may contain surface scratches or sag during the process, this traditional method has some disadvantages: among other problems, the PMMA sheets may contain variations in thickness and surface defects. It has since been replaced by the more modern method for making PMMA, extrusion, which gives uniform quality.

"Cell Casting - A process in which a casting liquid is poured between two plates, usually glass, that have a gasket between them to form a cell to contain the casting liquid; then the resin solidifies, usually through polymerization or crosslinking." - A. Brent Strong

Ceramic heater

A ceramic heater as a consumer product is a space heater that generates heat using a heating element of PTC (Positive Temperature Coefficient) ceramic. Ceramic heaters are usually portable and typically used for heating a room or small office, and are of similar utility to metal-element fan heaters.

Commodity plastics

Commodity plastics are plastics that are used in high volume and wide range of applications, such as film for packaging, photographic and magnetic tape, clothing, beverage and trash containers and a variety of household products where mechanical properties and service environments are not critical. Such plastics exhibit relatively low mechanical properties and are of low cost. The range of products includes Plates, Cups, Carrying Trays, Medical Trays, Containers, Seeding Trays, Printed Material and other disposable items.Examples of commodity plastics are polyethylene, polypropylene, polystyrene, polyvinyl chloride, poly(methyl methacrylate) and more.

Cranioplasty

Cranioplasty is a surgical repair of a defect or deformity of a skull. Cranioplasty is almost as ancient as trepanation. There is evidence that Incan and Muisca surgeons were performing cranioplasty using precious metals and gourds. Early surgical authors, such as Hippocrates and Galen, do not discuss cranioplasty, and it was not until the 16th century that cranioplasty in the form of a gold plate was mentioned by Fallopius. The first bone graft was recorded by Job Janszoon van Meekeren, who in 1668 noted that canine bone was used to repair a cranial defect in a Russian man. The next advance in cranioplasty was the experimental groundwork in bone grafting, performed in the late 19th century. The use of autografts for cranioplasty became popular in the early 20th century. The destructive nature of 20th century warfare provided an impetus to search for alternative metals and plastics to cover large cranial defects. The metallic bone substitutes have largely been replaced by modern plastics. Poly(methyl methacrylate) (PMMA) was introduced in 1940 and is currently the most common material used. Research in cranioplasty is now directed at improving the ability of the host to regenerate bone. As modern day trephiners, neurosurgeons and craniofacial maxillofacial and plastic surgeons alike, should be cognizant of how the technique of repairing a hole in the head has evolved. 3-D techniques are often used to work out plate sizes, and research into the subject is ongoing. As of 2014, a team of surgeons at Johns Hopkins introduced a new pericranial-onlay cranioplasty technique in an effort to improve outcomes and minimize complications [ref - Gordon et al., Neurosurgery 2014].

Depolymerization

Depolymerization (or depolymerisation) is the process of converting a polymer into a monomer or a mixture of monomers. This process is driven by an increase in entropy.

Ethylene glycol dimethacrylate

Ethylene glycol dimethylacrylate (EGDMA) is a diester formed by condensation of two equivalents of methacrylic acid and one equivalent of ethylene glycol.EGDMA can be used in free radical copolymer crosslinking reactions. When used with methyl methacrylate, it leads to gel point at relatively low concentrations because of the nearly equivalent reactivities of all the double bonds involved.

It is used as a monomer to prepare Hydroxyapatite/Poly methyl methacrylate composites. EGDMA can be used in free radical copolymer crosslinking reactions.

Laser dye

Laser dyes are large organic molecules with molecular weights of a few hundred mu. When one of these organic molecules is dissolved in a suitable liquid solvent (such as ethanol, methanol, or an ethanol-water mixture) it can be used as laser medium in a dye laser. Laser dye solutions absorb at shorter wavelengths and emit at longer wavelengths. Successful laser dyes include the coumarins and the rhodamines. Coumarin dyes emit in the green region of the spectrum while rhodamine dyes are used for emission in the yellow-red. The color emitted by the laser dyes depend upon the surrounding medium i.e.the medium in which they are dissolved. However, there are dozens of laser dyes that can be used to span continuously the emission spectrum from the near ultraviolet to the near infrared.Laser dyes are also used to dope solid-state matrices, such as poly(methyl methacrylate) (PMMA), and ORMOSILs, to provide gain media for solid state dye lasers.

Magic angle spinning

In nuclear magnetic resonance, magic-angle spinning (MAS) is a technique often used to perform experiments in solid-state NMR spectroscopy and, more recently, liquid Proton nuclear magnetic resonance.By spinning the sample (usually at a frequency of 1 to 130 kHz) at the magic angle θm (ca. 54.74°, where cos2θm=1/3) with respect to the direction of the magnetic field, the normally broad lines become narrower, increasing the resolution for better identification and analysis of the spectrum.

In any condensed phase, a nuclear spin experiences a great number of interactions. The main three interactions (dipolar, chemical shift anisotropy, quadrupolar) often lead to very broad and featureless lines. However, these three interactions in solids are orientation-dependent and can be averaged by MAS. The nuclear dipole-dipole interaction, between magnetic moments of nuclei averages to zero only at the magic angle, θm . The chemical shift anisotropy, a nuclear-electron interaction, averages to a non-zero value. The quadrupolar interaction is only partially averaged by MAS leaving a residual secondary quadrupolar interaction. In liquids, e.g. a solution of an organic compound, most of these interactions will average out because of the rapid time-averaged molecular motion that occurs. This orientation averaging in solution is mimicked by MAS of a solid. This causes the signal to become much narrower, giving rise to the isotropic value (which is of interest for structural determination of solid materials and compounds) and spinning sidebands which occur at multiples of the spinning speed and can be used to determine the chemical shift anisotropy of the nuclei.

The physical spinning of the sample is achieved via an air turbine mechanism. These turbines (or rotors) come in a variety of diameters (outside diameter), from 0.70–15.0 mm, and are usually spun on air or nitrogen gas. The rotors are made from a number of different materials such as ceramics e.g. zirconia, silicon nitride or polymers such as poly(methyl methacrylate) (PMMA), polyoxymethylene (POM). The cylindrical rotors are axially symmetric about the axis of rotation. Samples are packed into the rotors and these are then sealed with a single or double end cap. These caps are made from number of different materials e.g. Kel-F, Vespel, zirconia or boron nitride depending on the application required.

Magic-angle spinning was first described in 1958 by Edward Raymond Andrew, A. Bradbury, and R. G. Eades and independently in 1959 by I. J. Lowe. The name "magic-angle spinning" was coined in 1960 by Cornelis J. Gorter at the AMPERE congress in Pisa.

Methacrylic acid

Methacrylic acid, abbreviated MAA, is an organic compound. This colorless, viscous liquid is a carboxylic acid with an acrid unpleasant odor. It is soluble in warm water and miscible with most organic solvents. Methacrylic acid is produced industrially on a large scale as a precursor to its esters, especially methyl methacrylate (MMA) and poly(methyl methacrylate) (PMMA). MAA occurs naturally in small amounts in the oil of Roman chamomile.

Methyl methacrylate

Methyl methacrylate (MMA) is an organic compound with the formula CH2=C(CH3)COOCH3. This colorless liquid, the methyl ester of methacrylic acid (MAA), is a monomer produced on a large scale for the production of poly(methyl methacrylate) (PMMA).

Organic field-effect transistor

An organic field-effect transistor (OFET) is a field-effect transistor using an organic semiconductor in its channel. OFETs can be prepared either by vacuum evaporation of small molecules, by solution-casting of polymers or small molecules, or by mechanical transfer of a peeled single-crystalline organic layer onto a substrate. These devices have been developed to realize low-cost, large-area electronic products and biodegradable electronics. OFETs have been fabricated with various device geometries. The most commonly used device geometry is bottom gate with top drain and source electrodes, because this geometry is similar to the thin-film silicon transistor (TFT) using thermally grown SiO2 as gate dielectric. Organic polymers, such as poly(methyl-methacrylate) (PMMA), can also be used as dielectric.In May 2007, Sony reported the first full-color, video-rate, flexible, all plastic display, in which both the thin-film transistors and the light-emitting pixels were made of organic materials.

PMMA

PMMA may refer to:

para-Methoxymethamphetamine, a stimulant drug

Philippine Merchant Marine Academy

Poly(methyl methacrylate), a transparent thermoplastic often used as a glass substitute

Polymer degradation

Polymer degradation is a change in the properties—tensile strength, color, shape, etc.—of a polymer or polymer-based product under the influence of one or more environmental factors such as heat, light or chemicals such as acids, alkalis and some salts. These changes are usually undesirable, such as cracking and chemical disintegration of products or, more rarely, desirable, as in biodegradation, or deliberately lowering the molecular weight of a polymer for recycling. The changes in properties are often termed "aging".

In a finished product such a change is to be prevented or delayed. Degradation can be useful for recycling/reusing the polymer waste to prevent or reduce environmental pollution. Degradation can also be induced deliberately to assist structure determination.

Polymeric molecules are very large (on the molecular scale), and their unique and useful properties are mainly a result of their size. Any loss in chain length lowers tensile strength and is a primary cause of premature cracking.

Separator (electricity)

A separator is a permeable membrane placed between a battery's anode and cathode. The main function of a separator is to keep the two electrodes apart to prevent electrical short circuits while also allowing the transport of ionic charge carriers that are needed to close the circuit during the passage of current in an electrochemical cell.Separators are critical components in liquid electrolyte batteries. A separator generally consists of a polymeric membrane forming a microporous layer. It must be chemically and electrochemically stable with regard to the electrolyte and electrode materials and mechanically strong enough to withstand the high tension during battery construction. They are important to batteries because their structure and properties considerably affect the battery performance, including the batteries energy and power densities, cycle life, and safety.

Solid-state dye laser

Solid-state dye lasers (SSDL) were introduced in 1967 by Soffer and McFarland. In these solid-state lasers, the gain medium is a laser dye-doped organic matrix such as poly(methyl methacrylate) (PMMA), rather than a liquid solution of the dye. An example is rhodamine 6G-doped PMMA. These lasers are also referred to as solid-state organic lasers and solid-state dye-doped polymer lasers.

Suspension polymerization

Suspension polymerization is a heterogeneous radical polymerization process that uses mechanical agitation to mix a monomer or mixture of monomers in a liquid phase, such as water, while the monomers polymerize, forming spheres of polymer.

This process is used in the production of many commercial resins, including polyvinyl chloride (PVC), a widely used plastic, styrene resins including polystyrene, expanded polystyrene, and high-impact polystyrene, as well as poly(styrene-acrylonitrile) and poly(methyl methacrylate).

Vasa Mihich

Vasa Velizar Mihich (born 1933), known as Vasa, is an American artist based in Los Angeles, California.

Born in Yugoslavia, Vasa has lived in Los Angeles since his arrival in the United States in 1960. He is an academically trained painter and was a professor at the University of California, Los Angeles in the Department of Design and Media Arts. He taught theories of color to understand interdependence and interaction of color and form, color and quantity, color and placement, and after-image.Now retired as a professor emeritus, Vasa focuses on his conceptual art practice. His studio, designed to accommodate the technology required for his work, is located in the heart of Los Angeles. He makes laminated acrylic sculptures that reflect and refract light. He has had solo exhibitions at galleries in the United States, Japan, Italy and Serbia, including the Museum of Contemporary Art, Belgrade, the San Diego Museum of Art, and the Palm Springs Desert Museum.

Vasa is best known for his sculptures made from colored pieces of the plastic, poly(methyl methacrylate), which is also known as acrylic and by the brand names Plexiglas and Lucite. Untitled from 1975, in the collection of the Honolulu Museum of Art, demonstrates the effect of these minimalist sculptures. The Denver Art Museum, the Hammer Museum (Los Angeles), the Hirshhorn Museum and Sculpture Garden (Washington, D.C.), the Honolulu Museum of Art, The Phillips Collection (Washington, D.C.), the Royal Museums of Fine Arts of Belgium (Brussels), the San Diego Museum of Art, the San Francisco Museum of Modern Art, and the Wilhelm Lehmbrech Museum (Duisberg, Germany) are among the public collections holding work by Vasa Mihich.

Chemical types
Mechanical types
Additives
Plastics processing
Products
Environment and health
Waste

Languages

This page is based on a Wikipedia article written by authors (here).
Text is available under the CC BY-SA 3.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.