The crack resistance of unidirectional fiberglass-reinforced plastics based on an epoxy matrix modified with polysulfone (PSU) and furfuryl glycidyl ether (FGE) was investigated. The combined addition of PSU/FGE modifiers to the epoxy matrix increases the crack resistance of glass-fiber-reinforced plastics (GFRPs). The effect of increasing the crack resistance of GFRPs varies depending on the modifier ratio. The greatest increase in crack resistance is achieved with a modifier ratio of 1/0.5. For this ratio, the value of GIRCM is 1.18 kJ/m2 (for unmodified GFRP, GIRCM = 0.72 kJ/m2). With an increase in the FGE concentration in the polysulfone-modified epoxy matrix, the crack resistance of GFRP decreases to a level of ~0.8 kJ/m2. The change in the crack resistance of GFRP is associated with the structure of the epoxy matrix containing different PSU/FGE ratios. A study of the fracture surfaces of GFRPs showed that the greatest increase in the crack resistance of composites is achieved with the formation of extended phases enriched with polysulfone in the epoxy matrix. The size of the dispersed phase is about 3 μm. A correlation has been established between the crack resistance of hybrid matrices and GFRPs. With an increase in the matrix crack resistance by 3.1 times (from 0.37 to 1.15 kJ/m2), the fracture toughness value of GFRP increased by 1.6 times (from 0.72 to 1.18 kJ/m2).
Petrova et al. (Sun,) studied this question.