Methacrylic Acid and Derivatives

Abstract

Methacrylic acid (MAA) and its derivatives exhibit a rich array of chemistries and have found wide use in commercial applications, especially as monomers for making various types of polymer products. The predominant manufacturing route to the two simplest methacrylates continues to be via the conversion of acetonecyanohydrin (ACH) in sulfuric acid to methacrylamide followed by either hydrolysis to MAA or esterification with methanol to give methyl methacrylate (MMA). Alternative routes have reached or are now approaching commercialization. These include processes based on either ethylene (C‐2), propylene (C‐3), methylacetylene (C‐3), or isobutylene (C‐4) feedstocks, as well as a separate ACH process which does not involve sulfuric acid. The later route, which starts with catalyzed hydration of ACH to hydroxyisobutyramide followed by esterification and dehydration steps to MMA, has an added benefit of recycling HCN as a raw material. The ethylene‐based routes typically involve formaldehyde condensation on either a propionaldehyde or propionic acid intermediate. The isobutylene‐based routes involve oxidation processes to reach the methacrylate backbone, often passing through methacrolein as an intermediate. The propylene‐based routes typically involve isobutyric acid or isobutyraldehyde intermediates. The methylacetylene‐based process appears to be the most selective overall, where a single reaction with carbon monoxide and methanol leads directly to MMA. All of the synthetic routes require various types of catalysts to promote the separate steps involved. In addition to providing more details on each of these processes, the following article also provides information on volumes, costs, health and safety for methacrylic acid and its derivatives.

A new route for the synthesis of methacrylic acid from 2-methyl-1,3-propanediol by integrating biotransformation and catalytic dehydration

“…The process provides significant environmental advantages over the acetone-cyanohydrin process used for methacrylic production, which is based on fossil gas or oil as raw material, uses corrosive sulfuric acid and toxic HCN, and produces 1.5 tons of ammonium bisulfate as waste per ton of MMA. 24 Hence, it provides a good model for comparing life cycle assessment of the new and the traditional routes. The approach is applicable for the selective oxidation of other polyols.…”

Synthesis of Methacrylic Acid by Catalytic Decarboxylation and Dehydration of Carboxylic Acids Using a Solid Base and Subcritical Water

“…Subsequently, work focused on metabolically engineering microbes to produce these biochemicals and catalytic conversion of these chemicals to drop-in ready products. , One area in which there has been little research is on the synthesis of industrial important vinyl polymers from biomass, such as methacrylic acid (MAA) and methyl methacrylic acid (MMA). MAA esters form the basis of flexible but hard polymers with excellent clarity, weatherability, and UV stability . Methacrylic acid (MAA) is used in production of plastics, moldings, fibers, resins and other organic compounds.…”

“…Methacrylic acid (MAA) is used in production of plastics, moldings, fibers, resins and other organic compounds. The major product of MAA and methyl methacrylate (MMA) is poly­(methyl methacrylate), with an annual consumption of 2.1 million tons. , …”

“…Currently, the hazardous acetone–cyanohydrin process is the main route for producing MAA . Toxic starting materials, high process cost, and the large amount of bisulfate waste are problems with this process.…”

Vapor phase condensation of methyl acetate with formaldehyde to preparing methyl acrylate over cesium supported SBA-15 catalyst

“…It is mostly produced by the traditional 13 acetone cyanohydrin (ACH) process [1]. In this route, it requires 14 large quantities of toxic and hazardous hydrogen cyanide, and it 15 produces copious amounts of ammonium sulfate wastes that are 16 discarded.…”