�Tetra Gels� have been attracting much attention in the field of functional gel materials. These gels are synthesized from two different tetra-arm star polymers with cross-reacting functional group at the end of each arm, giving favorable properties, like high transparency, high mechanical-strength, bio-compatibility and so on, because tetrahedral geometry of the arms enable the cross-linking point to distribute homogeneously. In this study, tetra-arm star-block copolymer was designed to prepare physically crosslinked gels, where the microphase-segregated domains are crosslinking points. Therefore, the crosslinking domains can be visualized, enabling us to discuss, in more details, the relationships between the network structure and mechanical properties. Firstly, high-molecular-weight tetra-arm star-block copolymers were prepared by living radical polymerization in an ionic liquid and/or under high pressure condition. The molecular weight distribution was still narrow up to high molecular weight (~106 g mol-1). The transesterification reaction enabled us to cut the obtained these block copolymers into four segments and hence to precisely characterize the initiation efficiency of block copolymers. They were swollen with ionic liquids to form ionic gels. Finally, the mechanical properties and network structures were investigated by dynamic viscoelasticity and small-angle x-ray scattering (SAXS) measurements, respectively.

Controlled synthesis of tetra-arm star-block copolymers and fabrication of gel with homogeneous network structure

248th National Meeting (2014)

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