Cryogenic properties of PEG/nano-SiO 2 co-toughened winding resin and its carbon fiber-reinforced composites

The epoxy/acid anhydride system was toughened with a homogeneous solution of surface-treated nano-SiO 2 and polyethylene glycol (PEG), which satisfies the specific requirements of wet winding processes and effectively enhances the performance of resin and carbon fiber composites at ultra-low temperatures (108K). The results show that when the uniform solution formed by 1 phr SiO 2 and 10 phr PEG is added, the tensile strength and elongation at break of the modified resin were increased by 21.4% and 16.1%, respectively, at room temperature. At 108K, the strength and modulus of the modified resin were increased, and the elongation at break was 2.8%. The fracture morphology was analyzed and compared at both room temperature and ultra-low temperature, verifying the relationship between material structure and properties across different temperatures. These findings offer both theoretical and empirical backing for the development of ultra-low temperature carbon fiber composite gas storage tanks.