SynopsisEpoxides are a class of highly reactive three-membered cyclic ethers that have been widely applied to material science and technology. Besides their importance as monomers, epoxides have another aspect as highly reactive reactants for organic synthesis, which has prompted us to investigate their chemical transformations into new cyclic monomers that exhibit characteristic reactivity. The focus of this manuscript is such potential of epoxides as precursors of new monomers, which has been demonstrated by the successful reactions of epoxides with carbon dioxide and carbon disulfide to afford the corresponding 5-membered cyclic carbonates and dithiocarbonates, respectively. These compounds undergo the exclusive and highly efficient reactions with amines, leading to the successful syntheses of polyurethanes and their sulfur-analogues that are potentially applicable to adhesives, coatings, and other functional materials. The recent progress in development of highly efficient and energy-saving processes of the transformations, as well as designs and syntheses of cyclic carbonates and dithiocarbonates having functional groups, are described herein.(Recieved March 5, 2010)

View full abstract

SynopsisEpoxy resins are indispensable organic insulating material in electronic device fields such as semiconductors and printed circuit boards. Along with those technical innovations, the improvement demand for epoxy resins has been diversified and advanced. In this review, regarding seven kinds of typical high performance epoxy resins that can provide higher curability, higher heat resistance, lower moisture property, lower dielectric property, higher flame retardancy, higher flexibility and toughness and ultra high purity in our many creations, the studies on their molecular designs, synthetic technologies and evaluations are described. The important points in the design approach of high performance epoxy resins are considered as follows; to design molecular structures based on theories of relation between molecular structures and physical properties, to choose best skeletons for the functionalization, and to find out synthetic methods by which the skeletons are able to be introduced into the best positions.(Received March 16, 2010)

View full abstract

SynopsisFatigue resistance is an important property for the epoxy resins which are used as structural materials. Various modifiers, such as elastomers, thermoplastic resins, inorganic fillers, etc., have been added to the epoxy resins in order to increase the fracture toughness. This review describes the effect of each toughening technology on the fatigue resistance of the modified epoxy resins. (Received April 1, 2010)

View full abstract

SynopsisHigher order structures of epoxy resins improved their thermal conductivities. Thermal conductivities were up to 5times higher than those of conventional epoxy resins by introduction of mesogen groups to form liquid crystalline structures which suppress phonon scattering. However, thermal conductivities of these epoxy resins are 1.0 W/m・K at a maximumand are still not enough to apply to electric devices which require high heat dissipation efficiency. We composed these resins and ceramic fillers to accomplish the epoxy resin composites which have both isotropic high thermal conductivities (10 W/m・K)and high electrical insulation ability. We conclude that the developed composites are effective for thermal management of electric and electronic devices.

View full abstract

SynopsisRecently, much attention has been paid for transparent and colorless polymer materials applied for optical devices, such as flat panel display, LED light source, etc. In this report, the synthetic methods of organic-inorganic hybrid materials based on epoxy resin and Si, Ti, Zr alkoxides were reviewed, as well as the control of refractive index and heat resistance of their hybrids.

View full abstract