Carbon fiber reinforced thermoplastic composites (CFRTP) are expected for structual materials of automobiles because of light weight, high strength and thermoformability. However most of them have lower strength in comparison with carbon fiber / epoxy laminates because of their poor adhesive strength toward carbon fibers. The authors have developed carbon fiber / acrylic copolymer composites with high strength by achieving the strong adhesion between fiber and matrix. As acrylic resin has poor solvent resistance, its application field has been limited. The aim of this study is to create carbon fiber reinforced acrylic composites with both high strength and good solvent resistance. Pseudo-crosslinks by ionic bonds were introduced into the acrylic matrix. The ionic crosslinks remarkably improved in the elastic modulus and the solvent resistance of the acrylic matrix. The lap shear adhesion tests and the bending tests were carried out for CF/acrylic resin with ionic crosslinks. The acrylic resin with ionic crosslinks showed the strong adhesion to the carbon fibers in comparison with unmodified CF/PMMA, leading to the high flexural strength of CFRTP laminates. Also, the ionic cross-linked CFRTP had excellent thermoformability.

Diblock copolymers consisting of a homopolymer of a amide functionalized norbornene, PA, and a random copolymer of a flexible dodecanyl norbornene and A, P(D-r-A), were prepared and characterized. These block copolymers showed higher toughness than those of simple block copolymers, PD-b-PA, and random copolymers, P(D-r-A). The toughening is attributed to the microphase separated structure composed of spherical domains of PA blocks with dense hydrogen bonds surrounded by a soft matrix of P(D-r-A) block. The sparse hydrogen bonds in the matrix act as dynamic crosslinks, serving as sacrificial bonds to toughen the polymer. Self-healing ability was also confirmed in this copolymer.

Phenoxy resin is an engineering plastic, which is widely used as an insulating mold material, for example self welding insulating sheets that have superior moldability and low-material costs. To improve heat-durability of the phenoxy resin, the material was doped with bismaleimide, which is a thermosetting material. We investigated the behavior of bismaleimide doped phenoxy resin in a heat treatment process by using a differential scanning calorimeter (DSC). We also investigated heat durability as a thermal index (T_i) of heat treated phenoxy resin with bismaleimide by using thermogravimetric analysis with the Ozawa－Flynn－Wall method. From a heat-flow profile in the DSC, the exothermic peak temperature of the bismaleimide doped phenoxy resin was lower than that of the bismaleimide. The glass transition temperature (T_g) of the heat treated phenoxy resin with bismaleimide was higher than the T_g of the non heat treated bismaleimide-doped phenoxy resin. In IR measurement, the number of hydroxyl groups of phenoxy resin with bismaleimide decreased after heat treatment. These results suggest that bismaleimide reacts with phenoxy resin. The T_i of the heat treated phenoxy resin with bismaleimide depends on the doping ratio of bismaleimide. Heat-durability of phenoxy resin increases by doping the resin with thermosetting materials, such as bismaleimide, and by subjecting the resin to heat treatment.

Model construction and characterization of a network structure of crosslinked phenolic resin were performed using atomistic molecular dynamics (MD) simulation, in order to clarify the structure-property relationship in the cured resin. The constructed network structure was verified by chemical structure, molecular weight, and scattering functions of various degree of crosslink.

In recent years, the electronically controlled automobiles such as electric and hybrid cars are increasing. ECU (Electronic Control Unit) installed in electric and hybrid cars is placed in more severe temperature environment such as installing the ECU directly on an engine, or integration of an electric machine integrating engine and electronic components, in the future. Therefore, the packaging materials for automobile used for the ECU is required to have the performance that can be mounted on severe temperature environment. One of the required performances is long-term heat resistance at 200℃ or higher. In this paper, the author’s studies are introduced on the modification method of bismaleimide resin, which is attracting attention as a highly heat resistant resin exceeding epoxy resin, which is mainly used as a resin for packaging materials.