Isocyanate CAS No. 661-20-1

Product Description

Isocyanate, a crucial chemical intermediate for polyurethane synthesis with extensive applications in household appliances, automobiles, and construction, is primarily produced via the phosgene process, which remains dominant in industrial production despite safety concerns due to phosgene's toxicity and hydrogen chloride's corrosiveness. The nonphosgene route, involving carbamate formation from nitro-amino compounds with reagents like carbon monoxide, dimethyl carbonate, or urea followed by thermal decomposition, presents a promising alternative. Structurally, the isocyanate functional group (R–N=C=O) exhibits high reactivity with nucleophiles, forming urethanes or ureas, but differs from the unstable isocyanate anion (CNO⁻), the conjugate base of isocyanic acid.

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Product Use & Characteristics

Identity & Structure

• Molecular formula: CNO⁻ (anion) or R–N=C=O (functional group)

• Molecular weight: 42.017 g mol⁻¹

• IUPAC name: isocyanate

• Geometry: linear (anion); planar R–N=C=O linkage (functional group)

Chemical Characteristics

• Pseudohalide anion; conjugate base of isocyanic/cyanic acid

• Highly reactive electrophile toward nucleophiles (–OH, –NH₂, H₂O, –COOH)

• Reactions form urethanes, ureas, CO₂; reacts with metal hydroxides to give urethane-like bonds and N-metal double bonds

• Anion unstable in isolation; organic isocyanates can polymerize or trimerize

Synthesis Methods

1. Phosgene route (industrial standard)
   – Amine + phosgene → isocyanate + HCl
   – Liquid- or gas-phase variants (e.g., MDI, TDI production)

2. Non-phosgene routes (green chemistry)
   – Reductive/oxidative carbonylation of nitro- or amino-compounds
   – Dimethyl carbonate or urea process → carbamate → thermal decomposition to isocyanate
   – Catalysts: Zn, ZnO, Cu, Fe, Bi, Zn–Al, Zn–Co, MOFs, ionic liquids, etc.

Biological Role

• Metabolite in Escherichia coli and humans (cyanate anion)

Uses

• Monomers for polyurethane synthesis: flexible & rigid foams, elastomers, coatings, adhesives, sealants, insulation, automotive and construction materials

• Curing agents, microcapsules, specialty biomedical scaffolds (lysine-based isocyanates)

Environmental / Health Notes

• Phosgene route: high toxicity, corrosive HCl, energy-intensive, subject to regulatory phase-out

• Organic isocyanates: strong respiratory and skin irritants, occupational asthma risk

• Shift to bio-based isocyanates from vegetable oils, lignin, amino acids, algae, cashew nut shell liquid to reduce CO₂ footprint and eliminate phosgene

Commercial Bio-based Examples

• Tolonate™ X FLO 100 (Vencorex)

• Desmodur® eco N 7300 (Covestro)

• STABIO™ PDI (Mitsui Chemicals)

Why us!

Qingdao Sigma Chemical Co., Ltd., established in January 2017 and headquartered in Qingdao, China, is a reliable chemical supplier. Specializing in pharmaceuticals, biochemical intermediates, and research chemicals, the company offers a diverse product portfolio, including peptides (e.g., Tirzepatide, Semaglutide), nootropics, veterinary products, and APIs, often marketed with ≥99% purity and COA certification. We provides R&D, custom synthesis, and contract manufacturing services at various scales, while claiming a global export presence across 100+ countries. With international warehouses in the USA, Europe, Australia, and Canada, Qingdao Sigma Chemical also facilitates drop-shipping and reshipments, positioning itself as a key supplier for laboratory and research applications.