γ辐照对玻璃布/环氧树脂层压板压缩性能的影响

Effects of γ radiation on compression properties of glass-cloth/epoxy laminated sheet

玻璃纤维/环氧树脂复合材料具有高绝缘性和高力学性能,常作为支撑材料用于高能物理和核物理试验,但其力学性能在辐照环境中将发生变化。根据玻璃纤维/环氧树脂复合材料在新一代北京正负电子对撞机(BEPCII)中的应用要求,研究了玻璃纤维/环氧树脂复合材料中的玻璃布/环氧树脂层压板γ辐照前后的压缩性能。研究表明:经20kGy的γ辐照后,玻璃布/环氧树脂层压板的压缩强度由辐照前的320.21 MPa下降为315.05 MPa,下降了1.61%;经200kGy的γ辐照后,玻璃布/环氧树脂层压板的压缩强度下降为312.30 MPa,下降了2.47%。利用扫描电镜对辐照前后的试件断口进行微观形貌观察,发现辐照对玻璃布没有明显影响,但使玻璃布与环氧树脂的结合度有所降低,环氧树脂的碎片化趋于明显,红外谱图显示环氧树脂在辐照后的降解反应强于交联反应。

Glass fiber/epoxy composites have high insulation and high mechanical properties. They are usually em- ployed as the supporting materials in high energy physics and nuclear physics tests. But the mechanical properties will vary in irradiation environments. As one kind of glass fiber/epoxy composites, glass-cloth/epoxy laminated sheet is employed according to the application requirements of new generation Beijing Electron and Positron Collider （BEPCII）. The compression properties of glass cloth/epoxy laminated sheet before and after γ irradiation were studied. The result shows that the compression strength of glass-cloth/epoxy laminated sheet reduces to 315.05 MPa from 320.21 MPa after the γ irradiation of 20 kGy, declining by 1.61%. The compression strength of glass-cloth/epoxy laminated sheet reduces to 312.30 MPa after the y irradiation of 200 kGy, declining by 2.47%. The fracture sections of the samples before and after irradiation were observed by SEM. The results show the glass- cloth does not change obviously and the binding degree of the glass-cloth and the epoxy declines after irradiation. The fragmentation of epoxy is more obvious. FTIR spectra indicates that the degradation reaction predominates over the crosslinking reaction of epoxy after irradiation.