The Suitability Evaluation of Aromatic Amorphous Thermoplastics as Matrix Resin for CFRTP Having High Thermal Stability

The mechanical properties of CFRTPs made with polyetherimide (CFRTP-PEI) and polyethersulfone (CFRTP-PES) and the interfacial shear strength between CF and each polymer (CF/PES and CF/PEI) have been investigated. The relationships between measured parameters have been also discussed. The modulus and strength of both CFRTP achieved over 85% and 80% of theoretical values calculated from the rule of mixtures, respectively. For this reason, it is thought that the interfacial adhesion of CF/PES and CF/PEI effectively works for mechanical properties. The modulus of both CFRTPs and the strength of CFRTP-PEI showed almost constant below 150 ̊C. On the other hand, the modulus of both CFRTP markedly decreased above 150 ̊C and the strength of CFRTP-PEI began to decrease above 100 ̊C. The modulus of CFRTP-PES at 100 ̊C became 70 % of that at 25 ̊C. The interfacial shear strength of CF/PES and CF/PEI didnʼt decrease but the mechanical properties of each polymer obviously decreased below 100 ̊C. These results suggest that the thermal stability of CFRTPs is influenced not by interfacial adhesion but by the mechanical properties of matrix resins.