Skip to product details

Chemical product profile

HONGKUN / PRODUCT DIRECTORY

n-Butyl isocyanate | CAS 111-36-4

A monofunctional aliphatic isocyanate carrying a straight-chain butyl group, used in isocyanate chemistry and investigated as a monomer for poly(butyl isocyanate).

CAS111-36-4
Molecular formulaC5H9NO
Molecular weight99.13 g/mol

Product overview

The N=C=O group gives n-butyl isocyanate its principal reaction site, while the linear C4 chain defines the organic substituent. It should be distinguished from isobutyl and tert-butyl isocyanates, and from butyl isocyanide, which has different connectivity. A single isocyanate group also sets it apart from the diisocyanates used to build conventional polyurethane networks. For material assessment, chromatographic composition and available NCO functionality provide complementary information. Water and other active-hydrogen contaminants are relevant because they can consume the reactive group before the intended transformation.

Chemical identity

Chemical name
n-Butyl isocyanate
CAS number
111-36-4
Molecular formula
C5H9NO
Molecular weight
99.13 g/mol

Application context

Butyl isocyanate has been studied in anionic polymerization to form poly(butyl isocyanate). This research application exploits the isocyanate functionality to build a polymer backbone and should be evaluated with the initiator system and molecular-weight requirements of the project. The same NCO group is a reaction site for nucleophiles in small-molecule synthesis. Buyers should define whether their priority is a molecular conversion or polymerization evaluation, since trace reactive contaminants may matter differently. Material identity, NCO assay and a suitable impurity profile form the basis for that discussion.

Chemistry and synthetic role

The molecule is CH3CH2CH2CH2–N=C=O: one isocyanate attached through nitrogen to a linear butyl chain.

Quality review

Confirm n-butyl and isocyanate identity

Use structure-sensitive identification to distinguish branched isomers and isocyanides.

Assess available NCO

Combine organic purity with a suitable NCO assay where the process requires it.

Control reactive contamination

Agree limits or tests for moisture and active-hydrogen contaminants relevant to the application.

Preparing a specification

Specify the linear n-butyl isomer, organic assay, NCO assessment and water/reactive-impurity controls. For polymerization, include the project’s initiator compatibility criteria.

Packaging and storage

Packaging and net weight are agreed for the selected grade, order quantity and destination. Check the actual supplier SDS and label for storage and transport requirements.

Documentation

Request a batch COA, SDS and the analytical methods for the acceptance criteria below. Confirm which supporting chromatograms and identity data are available from the selected manufacturer.

Procurement questions

Is butyl isocyanide equivalent?

No. Isocyanide and isocyanate have different formulas and functional groups.

Does GC purity always define reactive content?

A process may need direct confirmation of available isocyanate functionality.

Why can polymerization need additional controls?

Trace species may affect initiation, termination or the effective monomer charge.

Technical sources
  1. PubChem CID 8110NCBI / PubChem
  2. n-Butyl isocyanateMerck / Sigma-Aldrich
  3. Butyl isocyanate applicationSigma-Aldrich