Methyl-Methacrylate

Methyl methacrylate is an organic compound with the formula of 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). Production

The compound is manufactured by several methods, the principal one being the acetone cyanohydrin (ACH) route, using acetone hydrogen cyanide as raw materials. The intermediate cyanohydrin is converted with sulfuric acid to a sulfate ester of the methacrylamide, methanolysis of which gives ammonium bisulfate and MMA. The ACH route coproduce's substantial amounts of ammonium sulfate. Some producers start with an isobutylene or, equivalently, tert-butanol, which is sequentially oxidized first to methacrolein and then to methacrylic acid, which is then esterified with methanol. Propene can be carbonylated in the presence of acids to isobutyric acid, which undergoes subsequent dehydrogenation. The combined technologies afford more than 3 billion kilograms per year. MMA can also be prepared from methyl propionate and formaldehyde.

Uses

The principal application consuming approx 80% of the MMA, is the manufacture of polymethyl methacrylate acrylic plastics (PMMA). Methyl methacrylate is also used for the production of the co-polymer methyl methacrylate-butadiene-styrene (MBS), used as a modifier for PVC. Another application is as cement used in total hip replacements as well as total knee replacements. Used as the "glue" by orthopedic surgeons to make the bone inserts fix into bone, it greatly reduces post-operative pain from the insertions but has a finite lifespan. Typically the lifespan of methylmethacrylate as bone cement is 20 years before revision surgery is required.

Shortage

In 2010, the world experienced an MMA shortage, believed to be due to production facilities shutting down for economic reasons. One of the largest producers, Dow Chemical, surprised many purchasers when they announced a six month shut down of their plant that produced 60% of MMA

Molecular Formula:


 * C5H8O2 ||