An ABA type block copolymer with oligoalanine and methionine chains (the degree of polymerization＝5 and 11) was successfully synthesized by the chain growth polycondensation of N-phenoxycarbonyl derivative of L-amino acid (alanine and methionine) with poly(propylene oxide) having amino groups at the terminal group as an macroinitiator. The polycondensation proceeded smoothly by heating at 60 ℃ along with the elimination of phenol and CO₂ to afford block copolymers in high yield. Flexible and transparent films of block copolymers were readily fabricated by solvent-casting method on the Teflon substrates. The FT-IR measurement revealed that oligoalanine segment formed physically cross-linked network through hydrogen bond of β-sheet structure. On the other hand, oligomethionine chain formed predominantly α-helical structure. The mechanical strength of the prepared film was evaluated by a tensile test, and we found that the modulus and tensile strength increased as the degree of polymerization of the oligopeptide chain increased. β-Sheet-forming oligoalanine segment was more effective for the increment of physical property than α-helical structure. Owing to the highly solubility of block copolymer having oligomethionine chain, the mechanical strength was further improved when treated with hexamethylene diisocyanate to form the multi-block copolymer.

Recently, five-membered cyclic carbonates produced by the reaction of epoxide and carbon dioxide have been reported as an important monomer for functional polymer. In this study, multi-functional five-membered cyclic carbonate(CNC) was synthesized from o-cresol novolac glycidyl ether and carbon dioxide under atmospheric pressure in high yield. In addition, novel networked polyurethanes with hydroxyl groups (PHUs) were prepared by the polyaddition of CNC with various aliphatic diamines as hardener. PHUs were cast as flexible transparent and brown films. The glasstransition temperatures of PHUs were in the range from 107 to 133℃, which were lowered with increasing methylene chain length of diamines. Furthermore, the 5% weight loss temperatures of PHUs were relatively low, 249－296℃, because of decomposition and recombination of urethane linkage. Moreover, in the thermal decomposition of PHUs, it was confirmed that urethane linkage was preferentially decomposed to give urea linkage as previously reported.

High speed and large capacity of data communication and information processing are required in the highly developed ubiquitous information network society. The low dielectric loss materials (low dissipation factor and low dielectric constant) are regarded as the key to solve the difficult problem in a field of insulating materials for the high frequency data communication. In order to lower the dielectric loss, dipole moment of the high frequency materials should be lowered. From the view point of this material design, curable vinyl resins are attractive as electronic materials bearing low dielectric loss. This review introduces development of curable vinyl resins from the viewpoint of precise control of polymer structure and dielectric properties.

Additive manufacturing of polymeric materials has attracted much attention. In this paper, we provide an overview of research on stimuli-responsive adhesion of hydrogels for fabrication of 3D hydrogels. We investigated an electrophoretic adhesion of hydrogels, wrinkle structures of adhesive interfaces, and stereoscopic molding of hydrogel architectures using gel-beads. Present adhesion method will be a powerful method for fabrication of hydrogel architecture with hierarchical structure such as scaffolds for cell-culture, carriers of drug release system, and soft-actuators.