Nano-fillers are expected as toughening agent for matrix resin of carbon fiber reinforced plastics. In this study fatigue crack propagation properties of epoxy resin with carbon nanotubes were investigated. Carbon nanotubes were well dispersed in the epoxy resin using a mechanical extruder. Carbon black particles were also used in order to investigate the effect of shape of nano-filler. The fracture toughness of epoxy with 1wt％ carbon nanotubes was 40％ higher than that of the unmodified epoxy resin, and was higher than that with same amount of carbon black particles. The carbon nanotubes enhanced the fatigue crack propagation resistance of epoxy resin. The effect of nanotube on the fatigue resistance was better in comparison with the carbon black particles. The fractographic observation revealed that there were many horse shoe markings on the fracture surfaces near the fatigue threshold, showing the plastic deformation of the epoxy matrix. Whereas the carbon nanotubes expanded size of the plastic deformation zone, the size of the carbon black composite was the same as that of unmodified resin. The shape of nanofiller affected the fracture process zone and the fracture energy during the fatigue crack propagation.

This paper reviews research focusing on how organisms form shapes of adhesive attachment, and introduced efforts in developmental biomimetics. As an example, gecko’s feet, leaf beetle’s feet, the process of forming byssus of mussels, the process of growing setae in the pupa of fruit-flies Drosophila melanogaster, and the biomimetic technology developed by modeling the biological method were introduced.

This article reviews epoxy resin formulations used for the fabrication via Stereolithography（SL） method. The basic concept of the SL method utilizing photocurable resins was come up with first by a Japanese researcher, Hideo Kodama, who applied the Japanese patent in 1980. The following year, his invention was open to public in a US scientific journal “Review of Scientific Instruments”. Kodama’s patent application was performed several years earlier than the US patent of C.W. Hull known as a leading player in popularizing the SL method and 3D printing apparatuses worldwide. The epoxy resin system widely used for 3D printing is the epoxy/acrylate hybrid formulation which was first applied for patent by a Japanese company in 1988. The epoxy/acrylate simultaneous photo curing system is considered to build up Interpenetrating Polymer Network （IPN），so-called Simultaneous-IPN（SIN）．The photo curing SIN system has been examined by many researchers, and the curing mechanism is being gradually clear along with the advantages and disadvantages of the SIN system. Another IPN system, Sequential-IPN（SIPN），which is built up typically from the thermalcuring epoxy and the photo-curing acrylate components through two-stage curing, is under study to apply for 3D printing. The purpose of utilizing SIPN system is to improve mechanical properties of the 3D objects formed.

This article describes the latest advances in cationic polymerization of vinyl monomers, focusing on SDGsconscious catalyst development. Many cationic polymerization reactions are catalyzed by metal Lewis acids, which can be toxic and/or have a negative impact on the environment. In addition, some of the metals that consist of catalysts for cationic polymerization and other chemical reaction are depletable. Thus, a recent focus of cationic polymerization is the development of metal-free catalyst systems, including polymerization via a RAFT mechanism without a metal-containing catalyst; photoinitiated polymerization systems; and polymerization reactions using organocatalysts. For the development new material without excess exploitation of fossil resources, other important topics of attention would be stereoselective or stereospecific polymerization of commonly used monomers that would provide higher performance polymers, and polymer synthesis from bio-based monomers.