为了达到增强硅气凝胶力学性能的目的,采用硅烷偶联剂KH550与KH560二步改性接枝玻璃纤维,进而制备纤维增强硅气凝胶。利用扫描电子显微镜、红外光谱仪、比表面及孔径分布仪、热重-差热分析仪、导热系数仪、电子动静态疲劳试验机等对其表征。实验结果表明：硅烷偶联剂改性玻璃纤维与硅气凝胶复合后网络结构更加均匀、骨架强度更加稳定、孔径多在30 nm以下、具有良好的热稳定性;同时,改性玻璃纤维的最佳添加量为20%（质量分数）,此时其密度为0.167 g/cm³,导热系数为0.018 5 W/（m·K）,接触角为127°,抗弯强度为1.042 MPa,抗压强度为0.669 MPa,达到预期实验目的。

In order to enhance the mechanical properties of silica aerogel,the silane coupling agent KH550 and KH560 were modified to grafted glass fibers in two steps,and then fiber reinforced silica aerogel were prepared.Scanning electron microscope,infrared spectrometer,specific surface and aperture distribution instrument,TG-DTA analyzer,thermal conductivity instrument and electronic dynamic and static fatigue testing machine were used to characterize the fiber reinforced silica aerogel.The results showed that after the glass fiber reinforced silica aerogel modified by silane coupling agent compounded with silica aerogel,the network structure was more uniform,the framework strength was more stable,the pore diameter was less than 30 nm,and the thermal stability was better.At the same time,the optimal addition amount of modified glass fiber was 20%（mass fraction）.At this time,the density was 0.167 g/cm³,the thermal conductivity coefficient was 0.018 5 W/（m·K）,the contact angle was 127°,the bending strength was 1.042 MPa and the compressive strength was 0.669 MPa.The expected purpose of the experiment was achieved.