FACTOID # 29: 73.3% of America's gross operating surplus in motion picture and sound recording industries comes from California.
 
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 
   
 
WHAT'S NEW
RELATED ARTICLES
People who viewed "Plexiglas" also viewed:
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > Plexiglas
Enlarge
Structure of PMMA: (C5O2H8)n
Enlarge
Structure of methyl methacrylate

Polymethyl methacrylate (PMMA) or polymethyl-2-methylpropanoate is the synthetic polymer of methyl methacrylate. This thermoplastic and transparent plastic is sold by the names Plexiglas, Perspex, Acrylite, Acrylplast and Lucite and is commonly called Acrylic glass or simply Acrylic. The material was developed in 1928 in various laboratories and was brought to market in 1933.

Contents

Properties

The material is often used in place of glass. Differences of the two materials include:

  • PMMA is lighter: its density (1190 kg/m3) is about half that of glass
  • PMMA does not shatter
  • The softness of PMMA leads to it being easily scratched compared with glass.
  • PMMA can be easily formed, by heating it to 100 degrees Celsius.
  • PMMA transmits more light than glass
  • Unlike glass, PMMA does not filter UV (ultraviolet) light. Some manufacturers coat their PMMA with UV films to add this property.
  • Up to wavelengths of 2800 nm, PMMA allows most IR (infrared) light to pass. Longer wavelengths of IR energy, up to 25,000 nm are essentially blocked. Special formulations of colored PMMA exist to allow specific IR wavelengths to pass while blocking visible light (for remote control or heat sensor applications, for example).

PMMA can be joined using cyanoacrylate cement (so-called "Superglue"), or by using liquid dichloromethane to dissolve the plastic at the join which then fuses and sets, forming an almost invisible weld. PMMA can also be easily polished, by which method cut edges (which turn opaque) can be returned to transparency.


To produce 1 kg of PMMA, about 2 kg of petroleum is needed. In the presence of air, PMMA ignites at 460 degrees Celsius; it burns completely to carbon dioxide and water.


If in the structure of PMMA the methyl groups (CH3) attached to the C atoms are replaced by single hydrogen atoms, we obtain polymethyl acrylate, a white soft rubbery material. It is softer than PMMA because its long polymer chains are thinner and smoother and can more easily slide past each other.


Uses

PMMA is used for instance in the rear lights of cars. The spectator protection in ice hockey stadiums is made of PMMA, as are the very largest windows and fish tanks in the world. The material is used to produce laserdiscs, and sometimes also for DVDs, but the more expensive polycarbonate (also used for CDs) has better properties when exposed to moisture.


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.


PMMA has a good degree of compatibilty with human tissue, and can be used for replacement intraocular lenses in the eye when the original lens has been removed in the treatment of cataracts. Hard contact lenses are frequently made of this material; soft contact lenses are often made of a related polymer, in which acrylate monomers are used that contain one or more hydroxyl groups to make them hydrophilic.


In orthopedics, PMMA bone cement is used to affix implants and to remodel lost bone. It is supplied as a powder and a liquid; when mixed, they yield a dough which then hardens. Dentures are often made of PMMA. In cosmetic surgery, tiny PMMA microspheres suspended in some biological fluid are injected under the skin to permanently reduce wrinkles or scars.


Recently, a blacklight-reactive tattoo ink using PMMA microspheres has surfaced. The technical name is BIOMETRIX System-1000, and is sold here (http://www.blacklight-tattoo-ink.com/) as "Chameleon Tattoo Ink". This ink is reportedly quite safe for use, and claims to be FDA approved for use on wildlife that may enter the food supply. If you desire a blacklight-reactive tattoo, many artists may balk at your request. This is because there was a type of ink called Everglow in circulation at some point, and might still be, which is made with blacklight-reactive poster paint. Everglow is NOT safe by any means as the dyes involved were never meant to be ingested, or for that matter injected into the skin.


See also

External link

  • Optical & Transmission Characteristics of Plexiglas (http://www.atofinachemicals.com/atoglas/pdfs/Optical_Transr.pdf) (manufacturer's data)

  Results from FactBites:
 
plexiglass - plexi - plexiglas - pmma - pvc (545 words)
plexiglass - plexi - plexiglas - pmma - pvc
Ce que l'on nomme en général "plexiglass" ou "altuglas" est en fait du P.M.M.A. En effet plexiglas est une marque, mais il est entré dans le dictionnaire comme nom commun ; pour comparaison le mot "frigidaire" qui était lui aussi une marque à l'origine.
Ce polymère est plus connu sous son nom commercial de Plexiglas (mais aussi sous les noms de Setacryl, Perspex, Acrylite, Acrylplast ou Lucite).
Altuglas International: Europe/Americas/Asia: North America Homepage (142 words)
From standard to very high impact PMMA, Plexiglas
Altuglas International Unveils New Plexiglas® Designer Color Collections for Creating Stunning Point-of-Purchase Displays
We manufacture and market PMMA resin and sheet products under the brand name Plexiglas
  More results at FactBites »

 
 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:

 


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m