Study of the influence of rubber on stremgth properties of carbon plastic

The use of elastomers allows us to purposefully change the structure of epoxy compositions, which largely determines the characteristics. Of particular interest are elastomers, such as silicone and polyurethane rubbers. In experimental works for the manufacture of carbon fiber plates, we used the method of manual molding with mechanical pressing. This technology is economical, does not require large labor costs, and less material consumption than when using other methods of formation. The effect of polyurethane and silicone rubbers as modifiers of increasing the impact strength of epoxy resin Etal-Inject-T hot curing has been studied. To determine the compressive strength of carbon fiber, the samples were tested on a universal test machine MUP200. The impact strength of carbon fiber was determined by the Charpy method. It is established that polyurethane and silicone rubbers have the same qualitative effect on the properties of epoxy resins. When modifying carbon fiber with polyurethane rubber with an increase in the content of up to 10%, the impact strength of carbon fiber increases to a maximum of 215 kJ/m2, with a significant increase in compressive strength up to 495 MPa. Optimal results were obtained with polyurethane rubber at 10% content of the substance. The main role of rubber in increasing the strength and elasticity of the material is that when the impact in a small amount of carbon fiber concentrates a lot of mechanical energy, the rubbers are stress concentrators, so the crack arises in the matrix adjacent to the elastomer (rubber). The increase in the toughness of the material can be associated with the formation of a dispersed phase of rubber, which loosens the structure of the cured epoxy resin.