본 연구에서는 표면처리에 따른 탄화규소(SiC)의 표면특성변화가 탄소섬유 강화 복합재료의 열안정성과 기계적 물성에 미치는 영향을 조사하였다. 표면처리된 탄화규소의 표면특성은 산·염기도, 접촉각측정 그리고 FT-IR을 통하여 알아보았으며, 열안정성은 TGA를 이용하여 조사하였다. 탄소섬유 강화 복합재료의 기계적물성은 interlaminar shear strength(ILSS) 그리고 critical strain energy release rate mode II(G_IIC)를 통하여 고찰하였다. 실험결과 산 처리된 SiC(A-SiC)와 오존처리된 SiC(O-SiC)는 미처리된 SiC(V-SiC)나 염기 처리된 SiC(B-SiC)에 비하여 산도가 증가하였고, 접촉각 측정 결과, 산성 용액과 오존 표면처리는 극성요소의 증가에 기인하는 SiC의 표면자유에너지를 증가시켰다. ILSS과 G_IIC같은 기계적 계면 성질은 A-SiC와 O-SiC로 향상되어졌는데, 이러한 결과는 좋은 젖음성이 최종 복합재료의 SiC와 에폭시 수지 메트릭스 사이의 계면결합력을 증가시키는 중요한 역할을 하기 때문으로 판단된다.

In this work, the effect of chemically wet and dry treatments of SiC was investigated in mechanical interfacial properties of carbon fibers-reinforced composites. The surface properties of SiC were determined by acid/base values, contact angles, and FT-IR analyses. The thermal stabilities of the carbon fibers-reinforced composites were investigated by thermogravimetric analysis (TGA). Also, the mechanical interfacial properties of the composites were studied in interlaminar shear strength (ILSS) and critical strain energy release rate mode II (G_IIC) measurements. As a result, the acidically treated SiC (ASiC) and ozone treated (O-SiC) had higher acid value than that of untreated SiC (V-SiC) or basically treated SiC (B-SiC). According to the contact angle measurements, it was observed that acidic solution and ozone treatments led to an increase of surface free energy of the SiC surfaces, mainly due to the increase of the specific (polar) component. The mechanical interfacial properties of the composites, including ILSS and G_IIC, had been improved in the specimens treated by acidic solutions and ozone gas. These results were explained that good wetting played an important role in improving the degree of adhesion at interfaces between SiC and epoxy resin matrix in a composite system.

Carbon Fibers-Reinforced Composites Surface Treatment Surface Properties Thermal Stability Mechanical Interfacial Properties

Schwartz MM, "Composite Materials Handbook," 2nd ed., McGraw-Hill, New York (1992)
Fitzer E, "Carbon Fibers and Their Composites," Springer-Verlag, New York (1985)
Park SJ, "Interfacial Forces and Fields: Theory and Applications," Ed. by J.P. Hsu., Chap. 9, Marcel Dekker, New York (1999)
Donnet JB, Bansal RC, "Carbon Fibers," 2th Ed., Marcel Dekker, New York (1990)
Park SJ, Kim MH, Lee JR, Choi S, J. Colloid Interface Sci., 228(2), 287 (2000) 
Park SJ, Donnet JB, J. Colloid Interface Sci., 206(1), 29 (1998) 
Fitzer E, "Carbon Fibers and Their Composites," Springer-Verlag, New York (1985)
Park SJ, Jang YS, J. Colloid Interface Sci., 237(1), 91 (2001) 
Breiner JM, Mark JE, Beaucage G, J. Polym. Sci. B: Polym. Phys., 37(13), 1421 (1999) 
Charrier JM, "Polymeric Materials and Processing," Hanser, New York (1990)
Boehm HP, Adv. Catal., 16, 179 (1966)
Adamson AW, "Physical Chemistry of Surfaces," 5th ed., John Wiley, New York (1990)
Park SJ, Kim JS, J. Colloid Interface Sci., 244(2), 336 (2001) 
Fowkes FM, J. Phys. Chem., 66, 382 (1962)
Owens DK, Wendt RC, J. Appl. Polym. Sci., 13, 1741 (1969) 
Horowitz HH, Metzger G, Anal. Chem., 35, 1464 (1963) 
King TR, Adams DF, Buttry DA, Composites, 22, 380 (1991) 
Munz DG, Shannon J, Bubsey LJ, Raymond T, Int. J. Fracture, 16, 137 (1980) 
Griffith AA, Philosophical Trans. Royal Soc. London Ser. A, 221, 163 (1920)
Compston PB, Jar PY, Burchill PJ, Takahasi K, Compos. Sci. Technol., 61, 321 (2001) 
Russell AJ, Street KN, "Factors Affecting the Interlaminar Facture Energy of Graphite/Epoxy Laminates," Proceedings of the Fourth International Conference on Composites Materials (ICCM-IV), Tokyo, Japan (1982)