2010 年 51 巻 12 号 p. 2259-2265
Homogeneous low voltage electron beam irradiation (HLEBI) improved the Charpy impact value (auc) of carbon fiber reinforced thermoplastic novolak-type phenol polymers (CFRTP) composite sheets with 2 mm thickness, although the irradiated depth estimated was 182.5±33.5 μm on both side surfaces. The auc values at low fracture probability (Pf) of 0.06 for CFRTP irradiated at 0.30 MGy (kJg−1) was 60 kJm−2, which was 32% higher (46 kJm−2) than for CFRTP before irradiation. Although the lowest impact values (as) estimated by three-parameter Weibull equation was zero for CFRTP before irradiation, HLEBI enhanced the as value. The highest as value was more than 59 kJm−2 for CFRTP irradiated at 0.30 MGy. Thus, HLEBI remarkably enhanced the as value, as well as the auc value at low Pf value. Since HLEBI enhanced the Weibull coefficient (n), it also enhanced the reproducibility of CFRTP samples. The maximum n value was found at 0.22 MGy HLEBI dose. The interfacial friction force, as well as the strengthening of both carbon fiber and novolak-type phenol resin probably contributed to the HLEBI effects to enhance the as value of CFRTP, as well as enhancement of reproducibility.
