Jessica Lu Block CPOLYMETHYL METHACRYLATE

Polymethyl methacrylate--most commonly known as Acrylic Plastic, Lucite, Plexiglas and PMMA (called by "lazy" scientists)--is a clear plastic often used as a replacement for glass since it very strong. Polymethyl methacrylate is an ester of methacrylic acid.

external image poly_methyl_methacrylate_jpeg.jpg

Basic Information:
Glass transition temperature: 85 to 165°C
(the range is very large due to different companies having different mixtures/formulas) Density: 1.19 g/cm3
Melting Point: 160°C
Boiling Point: 200°C
Ignition Point: 460°C
Softening Point: 125°C

A block of polymethyl methacrylate:

external image astp_lucite.jpg
picture from: http://www.apolloartifacts.com/images/astp_lucite.jpg
How it's made:
Polymethyl methacrylate was first made in 1843. It is usually made by polymerization (batch cell polymerization and continuous bulk polymerization) like all plastics. During polymerization, one of the bonds in the double bond in Methyl methacrylate (CH2=C(CH3) COOCH3) connects with another methyl methacrylate molecule. A chain is formed and continued until the correct chain (the polymethyl methacrylate chain) is formed.

A chain of methyl methacrylate to form polymethyl methacrylate:
external image mma3d.jpgexternal image pmma3d.jpg
pictures from: http://pslc.ws/mactest/pmma.htm

How we can use it/how it affects us:Though it has very low tolerance for chemicals, it has incredible weathering and scratch resistance and therefore perfect to use in aquariums since it doesn't break very easily and can withstand the pressure from the water. It is very useful to keep machines running. Mixing a bit of the Polymethyl methacrylate into lubricating oils and hydraulic fluids used in machines can stop these fluids from hardening, allowing machines to work under cold temperatures. Toy companies also use polymethyl methacrylate to replace glass so that if the toys break, the kids would not be harmed unlike glass which breaks into many small pieces. Some paint is also made of polymethyl methacrylate. Those paints are basically just polymethyl methacryate in some water (though something with both hydrophobic and hydrophilic groups is required since polymethyl methacrylate is hydrophobic). Other uses include: store fixtures and displays, lenses and lighting fixtures, light pipes, windows and skylights, sight gauges, furniture, outdoor signs and sculptures. It can also be used to replace lost/weak bones in orthopedic surgery. Polymethyl methacrylate can be obtained in pellet, powder, tube/stick or sheet form.

A guitar made of polymethyl methacrylate:
external image LuciteMMbass.jpg
picture from: http://img.photobucket.com/albums/v118/turquoisemoleeater/guitars/LuciteMMbass.jpg


Interesting facts:
Despite being used because it is safe (e.g. aquarium, ice hockey rink barriers, children's toys, etc.), while it is being made, it is very dangerous. If not monitored carefully, it can explode during the polymerization process at any time. Also, it is very dangerous to produce as it creates toxic fumes. Recently, it has been made required by law to have the products being made in a closed area and to have all the fumes be cleaned/neutralized before there are anyone could let the fumes out into the atmosphere. Another ironic thing is that it is highly flammable and even sometimes protected from sources of combustion.



Sources:
http://pslc.ws/mactest/pmma.htm
http://www.polymerprocessing.com/polymers/PMMA.html
http://www.britannica.com/EBchecked/topic/1551203/polymethyl-methacrylate
http://www.enotes.com/how-products-encyclopedia/acrylic-plastic
http://www.swicofil.com/products/278polymethylmethacrylate.html
http://www.boedeker.com/acryl_p.htm
http://www.rcsed.ac.uk/journal/vol43_1/4310052.htm