不飽和ポリエステル樹脂-炭酸カルシウム複合系の煮沸劣化に及ぼす炭酸カルシウムの配合効果

抄録

The effect of incorporation of calcium carbonate (CaCO₃) on degradation of mechanical properties of a cured unsaturated polyester resin (UP)-CaCO₃ system in boiling water has been studied.
The results showed that the incorporation of CaCO₃ increased remarkably the retention of flexural strength but decreased the retention of flexural modulus of the above system under the soaking condition in boiling water, while the incorporation of CaCO₃ decreased the initial flexural strength but increased remarkably the initial flexural modulus of the system.
A mechanism of the degradation in boiling water was proposed that the decrease of flexural strength was mainly due to the degradation of UP component and that of flexural modulus was due to absorption of water into the interface between UP and CaCO₃. Accordingly, the increase of CaCO₃ content which caused dilution of UP content increased the retention of flexural strength but decreased the retention of flexural modulus due to the increase of the interface between CaCO₃ and UP.