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Three isomers are common, varying by the positions of the isocyanate groups around the rings: 2,2′-MDI, 2,4′-MDI, and 4,4′-MDI. The 4,4′ isomer is most widely used, and is also known as 4,4′-diphenylmethane diisocyanate. [3] This isomer is also known as Pure MDI. MDI reacts with polyols in the manufacture of polyurethane. It is the ...
The addition of an isocyanate to a urea gives a biuret: R 2 NC(O)N(H)R' + R''NCO → R 2 NC(O)NR'C(O)NHR'' Reaction between a di-isocyanate and a compound containing two or more amine groups produces long polymer chains known as polyureas. Carbodiimides are produced by the decarboxylation of alkyl and aryl isocyanate using phosphine oxides as a ...
Hydrogenated MDI (H 12 MDI or 4,4′-diisocyanato dicyclohexylmethane) is an organic compound in the class known as isocyanates. [1] More specifically, it is an aliphatic diisocyanate. It is a water white liquid at room temperature and is manufactured in relatively small quantities.
4,4'-Diaminodicyclohexylmethane is the name for organic compounds with the formula CH 2 (C 6 H 10 NH 2) 2. It is classified as a diamine. In the epoxy industry it is often referred to as PACM, short for para-diaminodicyclohexylmethane. It is used as a curing agent for epoxy resins [1] It finds particular use in epoxy flooring. [2]
The molecule consists of a phenyl ring attached to the isocyanate functional group. It is a colourless liquid that reacts with water. Phenyl isocyanate has a strong odor and tearing vapours, therefore it has to be handled with care. Characteristic of other isocyanates, it reacts with amines to give ureas. [2]
Hexamethylene diisocyanate (HDI) is the organic compound with the formula (CH 2) 6 (NCO) 2. It is classified as an diisocyanate. It is a colorless liquid. [2] It has sometimes been called HMDI [3] but this not usually done to avoid confusion with Hydrogenated MDI.
4,4′-Methylenebis(2-chloroaniline) (also known as MOCA, MBOCA, and bisamine) is a substance used as a curing agent in polyurethane production. [3] MOCA is an aromatic amine which is structurally similar to benzidine , a known human bladder carcinogen.
C 6 H 5 OH + 2 CH 2 =C(CH 3) 2 → ((CH 3) 3 C) 2 C 6 H 3 OH. In this way, approximately 2.5M kg/y are produced. [2] Alkylation of phenol usually favours the para-position, and a strong lewis acid such as the Al 3+ ion is necessary to give selective ortho‑alkylation. [3] [4] If a conventional brønsted acid is used then 2,4-di-tert ...