Poly(methyl
methacrylate)


For Poly(methyl methacrylate) at a glance, click here!

Poly(methyl methacrylate), which lazy scientists call PMMA, is a clear plastic, used as a shatterproof replacement for glass. The barrier at the ice rink which keeps hockey pucks from flying in the faces of fans is made of PMMA. The chemical company Rohm and Haas makes windows out of it and calls it Plexiglas. Ineos Acrylics also makes it and calls it Lucite. Lucite is used to make the surfaces of hot tubs, sinks, and the ever popular one piece bathtub and shower units, among other things.

When it comes to making windows, PMMA has another advantage over glass. PMMA is more transparent than glass. When glass windows are made too thick, they become difficult to see through. But PMMA windows can be made as much as 13 inches (33 cm) thick, and they're still perfectly transparent. This makes PMMA a wonderful material for making large aquariums, whose windows must be thick in order to contain the high pressure millions of gallons of water. In fact, the largest single window in the world, an observation window at California's Monterrey Bay Aquarium, is made of one big piece of PMMA which is 54 feet long, 18 feet high, and 13 inches thick (16.6 m long, 5.5 m high, and 33 cm thick).

PMMA is also found in paint. The painting on your right, Acrylic Elf was painted by Pete Halverson with acrylic paints. Acrylic "latex" paints often contain PMMA suspended in water. PMMA doesn't dissolve in water, so dispersing PMMA in water requires we use another polymer to make water and PMMA compatible with each other. To see how we do this, go visit the poly(vinyl acetate) page.

But PMMA is more than just plastic and paint. Often lubricating oils and hydraulic fluids tend to get really viscous and even gummy when they get really cold. This is a real pain when you're trying to operate heavy equipment in really cold weather. But when a little bit PMMA is dissolved in these oils and fluids, they don't get viscous in the cold, and machines can be operated down to -100 oC (-150 oF), that is, presuming the rest of the machine can take that kind of cold!

PMMA is a vinyl polymer, made by free radical vinyl polymerization from the monomer methyl methacrylate.

As you can see from the picture, the structure of methyl methacrylate kind of looks like Massachusetts. But Massachusetts doesn't polymerize, because there's only one. Here's a better, 3-D look at the monomer methyl methacrylate:

PMMA is a member of a family of polymers which chemists call acrylates, but the rest of the world calls acrylics.

Another polymer used as an unbreakable glass substitute is polycarbonate. But PMMA is cheaper!

Other polymers used as plastics include:

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