Capa Monomer Caprolactone monomer Solvay Caprolactones Polycaprolactones, thermoplastic Caprolactone monomer is a colourless, mobile liquid. The lactone ring is relatively easily opened by compounds containing active hydrogen atoms such as alcohols. Each ring opening step forms a terminal, primary hydroxyl group. It is particularly valuable as a flexibilising monomer in formulating thermosetting acrylic resins and unsaturated polyester gel coats. It can also be used as a reactive diluent in epoxy resins. Colourless caprolactone monomer. Possesses a lactone ring that is relatively easily opened by compounds containing active hydrogen atoms such as alcohols. Each ring opening step forms a terminal, primary hydroxyl group. Used as a flexibilising monomer in formulating thermosetting acrylic resins and unsaturated polyester gel coats. Can also be used as a reactive diluent in epoxy resins.