Methyl methacrylate
Properties
Colourless liquid, volatile and flammable.
Relative density: 0.9440.
Melting point: – 48℃.
Boiling point: 100～101℃.
Flash point (open cup): 10°C. Refractive index 1.4142.
Refractive index: 1.4142.
Vapour pressure: (25.5℃) 5.33kPa.
Soluble in ethanol, ether, acetone and other organic solvents.
Slightly soluble in ethylene glycol and water.
Easy to polymerise in the presence of light, heat, ionising radiation and catalyst.
Preparation method
Acetone cyanohydrin route: acetone cyanohydrin reacts with sulfuric acid to form methacrylamide sulfate, which is hydrolysed and then esterified with methanol to obtain the crude product of methyl methacrylate, and then the finished product is obtained by salting out, crude distillation and rectification. Usually acetone cyanohydrin is produced from sodium cyanide.
Isobutene route: Isobutene is oxidised in two stages with air in the presence of a molybdenum catalyst. Isobutene is first oxidised to methacrolein and then further oxidised to methacrylic acid. Methacrylic acid is esterified with methanol to give methyl methacrylate. Recently, a one-step oxidation process has been developed. Isobutylene is oxidised directly to methacrylic acid using N2 04 as the oxidising agent and K2 C03 or Mr102 as the catalyst. It is then esterified with methanol.
Propylene route: Propylene, carbon monoxide and methanol undergo a carbonylation reaction to produce methyl 2-methoxyisobutyrate, which is then decomposed into methyl methacrylate and methanol by hydrolysis.
Isobutyraldehyde one-step oxidation method: Using heteropolyacids and their salts as catalysts, methacrylic acid is produced by one-step oxidation of isobutyraldehyde, and methacrylic acid is then esterified with methanol to methyl methacrylate.
Uses
1. Used in the manufacture of organic glass, coatings, lubricant additives, wood infiltration agent, paper varnish and so on.
2. Methyl methacrylate is not only an organic chemical material, but also can be directly applied as a chemical product. As an organic chemical material, it is mainly used in the production of plexiglass (polymethyl methacrylate, PM-MA), also used in the manufacture of polyvinyl chloride additives ACR and as the second monomer used in acrylic production. In addition, it has been widely used in adhesives, coatings, resins, textiles, paper and other industries. As a chemical product, it can be directly applied to leather, ion exchange resin, paper polish, textile printing and dyeing auxiliaries, leather treatment agent, lubricant additives, crude oil degreasing agent, wood and soft wood impregnating agent, motor coil impregnating agent, insulating potting material and plastic-type emulsions of plasticisers, floor polishing, unsaturated resins modification, high-level esters of methacrylic acid, and so on in many fields.
3.Organic synthetic monomer. Also used in the manufacture of other resins, plastics, coatings, adhesives, scale inhibitors and dispersants, lubricants, wood infiltration agent, motor coil impregnation agent, paper varnish, printing and dyeing auxiliaries and insulating perfusion materials.
4. Used as monomer of organic glass, also used in the manufacture of other resins, plastics, coatings, adhesives, lubricants, wood and cork impregnating agent, paper varnish, etc..
Safety information
This product is less toxic. The oral LD50 for rats is 9400mg/kg, the lethal concentration by inhalation is LC5015.33g/m3, and the maximum permissible concentration for operation is 410mg/m3.
However, its olfactory threshold is 130 ~ 250mg / m3, when its concentration has not yet reached the toxicity of its strong odour has made people intolerable.
Only a very small number of people will develop a red rash when their skin is exposed to methyl methacrylate.
As the raw material sodium cyanide and intermediate hydrogen cyanide for the production of methyl methacrylate are highly toxic, the production equipment must be strictly ensured to be airtight and well ventilated, and the operators should be equipped with strict protective measures and necessary protective gear.
The operator should take strict protective measures and be equipped with necessary protective gears. When poisoning is found, it should be moved to a fresh air place immediately and rescued in time.
Packed in galvanised iron drum or aluminium drum. Specification 160kg.
Store in cool and ventilated warehouse, away from fire and heat source, avoid direct sunlight.