Caprolactone

Caprolactone (CAS 502-44-3), also known as ε-caprolactone or CL, is a cyclic ester monomer used as a building block in polymer synthesis and as a reactive diluent in coating and resin systems.

Where is Caprolactone used?

• Plastics and coatings: polymerized to polycaprolactone (PCL), a biodegradable thermoplastic for packaging films, adhesives and flexible molded parts
• Printing inks and packaging: caprolactone-based polyols for flexibility and adhesion, also enhancing solvent resistance in polyurethane systems
• Personal care: reactive ingredient in film-forming polymers and specialty esters for skin and hair formulations
• Food: at trace levels it contributes creamy, coconut-like notes as a flavoring agent.

Good to know: Also known as ε-caprolactone or CL; FEMA code or E number where applicable. Not typically listed under FCC, USP, Ph. Eur., BP, EP or ACS.

Commercial specifications

• Purity typically 99% or higher
• Technical and polymer-grade specifications
• Packaging from drums to isotanks