In this study, the flame retardancy of polyphenylene ether(PPE) and PPE/polystyrene(PS) alloy was examined by thermal degradation behavior and other considerations. As a result, various carboxylates were found to have a notable effect on the flame retardancy of PPE/PS alloy though the carboxylates are widely used as safe food additives. Especially, sodium carboxylate with benzene ring showed the strongest flame retardancy among the candidates. Based on the surface observation and its analysis of PPE/PS alloy in early stage of burning test, on the other hand, it was found that the both components of the alloy are not pyrolyzed independently at each tem-perature and the alloy is pyrolyzed in relatively homogeneous manner such as a single component polymer. In addition, the pyrolysis products of PPE were composed of many kinds of monomer and dimer. The formation process of monomer component was examined by pyrogram analysis.
This paper describes a durability evaluation method for wooden members reinforced by carbon fiber material. Repairing work using carbon fiber material was recently conducted in the Shinkyo, a historical wooden bridge. A carbon fiber plate and sheet were attached around strengthened parts of girders. It is required to evaluate the durability of a carbon fiber reinforcement part from a viewpoint of maintenance management. Environmental conditions such as temperature and humidity around member of the wooden bridge were measured for four months to grasp conditions of the construction site. These are used as experimental conditions for a carbon reinforced wooden member, and natural exposure test and heat cycle test were carried out. Using these tested members, bending performance and adhesion characteristics were analyzed. Finally, a mechanism of deterioration was considered from the correlativity of the adhesion and the bend characteristic.