Abstract
ILSSs of 7 kinds of CFRPs whose matrices were thermostable resins including newly developed ones were measured by a short beam method of three point bending in the temperature range between room temperature and 250°C, and the relation with resin properties was examined. By observing the side surface of the specimen whose ILSS had been tested, failure mode at high temperatures was also examined.
There were two types of temperature dependent curves of ILSS. ILSS decreased linearly with increasing temperature in one type. In the other type, the degree of ILSS decrease became larger with increasing temperature, and the ILSS-temperature relation did not follow a linear line but bent curve. Such curves were considered to depend on thermal property of the matrix resins. The ratio of the ILSS value at high temperatures to that at room temperature, ILSS retention, was highest for PMR-15 matrix CFRP at 200°C and 250°C. The apparent elastic degree retention of matrix resin estimated from the slope of load-deflection curves on ILSS test corresponded with ILSS retention, and a linear correlation between Tg of the matrix resin and ILSS retention was recognized. It was also confirmed that the failure mode of the specimens measured at 200°C and 250°C was shear failure.
