A novel crystalline polymer （BP-BP Polymer） was synthesized by reacting an epoxy resin having a biphenylene structure with 4,4’-dihydroxybiphenyl. Then, the properties of BP-BP Polymer were compared with those of the polymer from an epoxy resin having a diphenylene ether structure and 4,4’ -dihydroxydiphenylether （DE-DE Polymer）． The melting point of BP-BP Polymer in differential scanning calorimetry was 337.4 ℃ , which was 151.6 ℃ higher than that of DE-DE Polymer, and the glass transition temperature in dynamic mechanical analysis was 135.5 ℃ , which was 41.4 ℃ higher than that of DE-DE Polymer. In addition, the thermal conductivity of BP-BP Polymer was 0.36 W / m·K, which was higher than that of DE-DE Polymer.

We have developed a novel pressure-sensitive adhesive（PSA） based on tackifier（TF） surface segregation. X-ray photoelectron spectroscopy showed higher concentration of TF at the surface （about 80 wt%） relative to the total amount（2 wt%）．The depth of the TF layer was about 20 nm. The properties of the PSA based on TF surface segregation were compared with the general PSAs. The peel strength of the general PSAs were relatively high at room temperature, but decreased drastically under high temperature, such as 85℃ . On the other hand, the PSA based on TF surface segregation maintained high peel strength under high temperature. The surface segregation of TF didn’t influence the viscoelasticity behavior measured by dynamic mechanical analysis. It was assumed that the improvement of the adhesion properties under high temperature related to the high Tg region near the surface of the PSA formed by the surface segregation of TF. The PSA based on TF surface segregation significantly improved the blister resistance for laminating optical films to display parts and the heat resistance for using decorative films in automobile parts.

Polyglycerol, polymerized glycerol, is a highly viscous and hygroscopic liquid. It is can be utilized cosmetics, food additive, and raw material for various derivatives. We developed a novel polyglycerol-based monomers which consist of polyglycerol skeleton, with or without polyethylene oxide chain, and reactive end groups such as epoxy, acrylate, methacrylate, and alkoxysilane. The polyglycerol backbone and its EO adduct act as soft segments in cross-linked network. After the examination of their flexibility, curing rate, and stress relaxation effect, we successfully applied these materials to flexible coating. Moreover, our research indicated that the hydrophilic nature of the polyglycerol-EO skeleton enables the moisture to be absorbed/released repeatedly. By applying this technology, we offer the wide potentials of polyglycerol-based soft materials including novel hydrogel and anti-fog coating.