Crosslinked polydiacetylene and its two- and three-component interpenetrating polymer networks (IPNs)

The synthesis of crosslinked polydiacetylene poly4ECMU (a polydiacetylene with ethoxy carbonyl methylene urethane substitution): where R = ? (CH₂)₄OCONHCH₂COOCH₂CH₃] was carried out utilizing its polar and flexible substituent groups. Polydiacetylene was crosslinked by the formation of allophanate linkages utilizing urethane groups in the substituent groups of the polydiacetylene. Two-component IPNs of polydiacetylene poly4BCMU (a polydiacetylene with butoxy carbonyl methylene urethane substitution): where R = ? (CH₂)₄OCONHCH₂COO(CH₂)₃CH₃] and an epoxy resin (diglycidyl ether of Bisphenol A) were synthesized. Two-component IPNs of poly4ECMU with the above epoxy resin were also synthesized. For the first time, two-component stiff-backbone IPNs of two different kinds of polydiacetylene (poly4BCMU and polyECMU) and a three-component IPN of poly4BCMU, poly4ECMU, and the epoxy resin were synthesized. IPNs with fewer allophanate linkages were also made in order to examine morphological differences between them. The glass transition behavior of these networks was studied using differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) by means of a Rheovibron.