High, internal phase emulsion foams: Copolymers, and interpenetrating polymer networks

High internal phase emulsion (HIPE) copolymer and interpenetrating network foams were prepared from 2-ethylhexyl acrylate (EHA), styrene (S) and divin ylbenzene (DVB) using a unique process. The morphologies, thermal propertie s, and dynamic and static mechanical properties of these foams were investi gated. The glass transition temperatures and damping properties of the EHA/ S copolymer foams vary with its composition. IPN foams with very broad tan delta peaks were obtained. The damping properties of IPN foams were tailore d through changing copolymer composition and monomer composition. The IPN f oams based on a copolymer foam and styrene had a broader tan delta, peak, a higher glass transition temperature and a higher modulus than the copolyme r foams of similar overall styrene contents. It is therefore possible to pr epare novel damping foams based on polyHIPE foams through the synthesis of interpenetrating polymer networks.