Taka Norimasa, Aoyagi Yujin, Okawa Seigo and Uoshima Katsumi
Objective: The aim of this study was to evaluate the effects of silanization conditions on the mechanical properties of the SiC fiber-reinforced resin.
Materials and Methods: A mixture of urethane dimethacrylate and Triethylene Glycol Dimethacrylate (TEGDMA), with camphorquinone and 2-(N,N-dimethylamino)ethyl methacrylate as the visible-light initiator, was prepared as a matrix resin. The SiC fiber containing 10 mass% oxygen was silanized by two methods, using experimental silane coupling agents containing 0.5, 1.0, and 2.0 mass% 3-(Methacryloyloxy) Propyl Trimethoxy Silane (γ-MPTS). The silanization methods were the drying method, which enabled silanization at atmospheric conditions for two weeks, and the heating method, which enabled silanization at 100°C for 30 min. After silanization, SiC fibers were analyzed by Fourier Transform Infrared (FTIR) spectroscopy. Mechanical properties of experimental SiC fiber-reinforced resin were measured by the three-point bending test according to ISO 4049:2009, and the fracture surface of SiC fiber-reinforced resin was observed using an Electron Probe Micro Analyzer (EPMA).
Results: The FTIR absorbance peaks at 815 cm-1 attributed to the Si-O-CH3 groups of the γ-MPTS and 1087 cm-1 attributed to the Si-O-Si siloxane bonding were observed on the SiC fiber silanized with 1.0 mass% γ-MPTS by the drying method. Moreover, EPMA observation showed that these SiC fibers were covered with the matrix resin. Thus, these SiC fibers could adhere chemically to the matrix resin. The flexural strength and modulus of the fiberreinforced resin containing the SiC fiber silanized with 1.0 mass% γ-MPTS using the drying method were 238.7 ± 41.1 MPa and 6.0 ± 1.1 GPa, respectively. In contrast, those of the SiC fiber-reinforced resin containing the SiC fibers silanized by the heating method was not improved.
Conclusion: The reinforced resin containing the SiC fiber silanized with 1.0 mass% γ-MPTS by the drying method showed mechanical properties superior to those of the other SiC fiber-reinforced resin.