せん断力によるブレーキ材料用フェノール樹脂硬化物の分解 : 第1報, 抽出物の分子量分布

抄録

In order to clarify the formation mechanism of liquid phase degradation products that cause the fade phenomenon, we carried out the solvent extraction of cured phenolic resin, and then the molecular weight distribution of the extracts was measured. In the case of the extracts of cured phenolic resin powder to which a shearing force was applied in a steel mill, a peak appeared on the high molecular weight side of the molucular weight distribution curve, and the average molecular weight increased. On the other hand, the average molecular weight of the extracts of cured phenolic resin powder, to which heating with an electric furnace was applied, was the same as before heating or decreased. From the above results it was found that the products of degradation due to heat alone are of the gas phase, but those formed by the simultaneous action of heat and shearing force have large molecular weight and are apt to be of the liquid phase.