Designs of functional materials with associative dynamic covalent bonds
Conventional covalently cross-linked materials have sufficient material strength, while these are lack of the recyclability and reprocessability. Vitrimers are a new class of cross-linked materials that are capable of network topology alternation through the “associative” dynamic bond-exchange mechanism, which has been recently invented to solve the problem of conventional cross-linked materials. Notably, during the bond-exchange at high temperature, vitrimers do not show sudden flow, unlike thermoplastics, because the network integrity and the constant cross-link density is well maintained owing to the associative bond-exchange mechanism. This is one of the greatest advantages of vitrimer materials in terms of materials processing. Our group has reported various molecular designs, functions (reprocessablity, healability, recyclability, adhesion, etc), and tuning methods of the vitrimeric properties, which could contribute to realization of the practical application of vitrimer concept.
Creation of tough polymeric materials
To satisfy the current and future demands for new materials to tackle the depletion of petroleum resources, tough polymeric materials with prolonged life-time have been enthusiastically studied. Tough materials are especially important in the field of next-generation vehicles in which metal components should be replaced with polymeric resins in more various sections. Our group has developed the methodologies to toughen both glassy and soft polymeric materials by incorporating molecular mechanisms to dissipate the internal stress under deformation. In addition, we are studying the way to control the fracture of materials, using precise patterning of modulus, which may open the new research field of polymeric materials.
Functionalization and basic physical properties of block copolymer-based materials
Block copolymer composed of incompatible components self-assemble into period structures at a nanometer scale. The structural characteristics vary depending on the molecular characteristics of the component block copolymers. The physical properties of block copolymer-based materials are governed by the nano structures. Our group has developed functionalization and enhancement of physical properties of block copolymer-based materials, by utilizing precise synthesis techniques and various cross-linking approaches. These challenging can contribute to further widening of the practical application range of block copolymer-based materials.