Generation of cellular materials by electron beam irradiation

A method utilizing electron beam irradiation has been developed for producing closed cell flexible foams from acrylated urethane monomers and oligomers. This process consists of pre-foaming the prepolymer mixture before irradiation by a mixing technique, and then casting the unpolymerized foam onto a substrate where it can be subsequently cured using electron beam radiation. Other processes either rely on a surfactant to support the cellular structure before irradiation, or utilize prepolymerization, heat and then a chemical (generated by radiation) or physical blowing agents to generate the foam. The advantages of this process are that no preheating is involved and no prepolymerization of the mixture before irradiation is required. In addition, no blowing agent (chemical or physical) and no surfactant are required for producing the cellular structure. A detailed outline of this process along with structures and properties of these foams are presented along with comparison with other foam generation processes