Mechanical Properties of SiC-fiber Reinforced Composite Resin

Objectives: The purpose of this study was to evaluate the effect of SiC surface silanation on mechanical properties of SiC fiber reinforced composite resin.
Methods: A matrix resin consisted of UDMA and TEGDMA (70:30 mass%). The SiC fiber containing 10 mass % oxygen was used for reinforcement, and silanized with 1 mass%γ-MPTS and a commercialy available product (PZ primer ®). To silanize the SiC fiber, it was immersed in 1 mass % γ-MPTS solution for 1 hour at room temperature, then kept dry for 14 days at room temperature. On the other hand, PZ primer was put on the fiber, and then kept dry for 10 min at room temperature. Aproximately 1,500 silinized SiC fibers were embedded in the bottom of the specimen (tensile side). According to ISO 4049, three-point bending test conditions and specimen size were determined. After spcimens were stored for 24 hours at 37 °C, flexural strength of specimens was measured with universal testing machine. Elastic modulus of specimens was calculated with SHIKIBU software. All data were statistically analyzed with Student’s t test (p<0.05).
Results: Flexural strength of 1 mass% γ-MPTS and PZ primer specimens were 238.7±41.1, 138.3±22.9 MPa respectively. Elastic modulus of theirs were 6.0±1.1 and 3.4±0.5 GPa. On the other hand, flexural strength of matrix resin and reinforced with non silanized SiC fiber specimens were 97.8±4.2, 135.7±40.5 MPa. Elastic modulus of them were 2.1±0.1, 3.4±0.7 GPa. Flexural strength and elastic modulus of 1 mass% γ-MPTS specimens were significantly higher than other specimens.
Conclusions: Within the limitations of this study, these results suggested that the 1 mass% γ-MPTS silanization agent was better than commercially available PZ primer.