Fabrication And Characterization Of Low Temperature Resistance Glass Fabric/epoxy Composites

Because of its high specific strength and modulus ratio, composite has become the one of four main materials, including metal material, high molecular material and ceramics. And composits has been applied for many field of daily life, especially at aerospace and national defence. A lot of work has been done about active application of resin composites reinforced by fiber.With the development of science and technology, the standard of material property has become stricter and stricter, such as the temperature of lunar surface is between sub-zero two hundred and above freezing two hundred, whice lead to rough-weather works for equipments. Composites reinforcing by fabric usually could adapt high temperature, and the research of its properties at cryogenic temperatures has been rare.Epoxy (EP) resin as a kind of superconduct-insulated material is hope of a high intensity and great crack ductility, with the electrical insulating properties of superconduct-insulated materials. So the mechanical properties of epoxy resin must be modified at room and cryogenic temperatures.In this paper, on the basis of the structure characteristic of the curing epoxy resin, a high cross-link density and elastic modular, the behavior of its crack growth shows that it is of typical brittleness, many vital problems have been analysised and discussed, such as matrix modification, design of molding process, material properties and influencing factors.Initially, epoxy resin has been modified with nano-SiO₂ by the sol-gel method. The disperse conditions of nano-SiO₂ in the matrix were examined by transmission electron microscope (TEM). The experimental results indicated that nano-SiO₂ particles agglomerated easily at the situation of alkali catalyst, and solving method by changing sequence of additional of reagent. Further studies on content of nano-SiO₂ approved that the tensile strength and elongation at break attain a peak at approximately 2% silica content.At the aspect of molding process of composites, resin transfer moulding (RTM) technology has been used, and cloth of fiber glass as reinforced materials. The mechanical properties were compared at room and cryogenic temperatures. The results showed that the tensile strength, tensile modulus of composites have been enhanced greatly at cryogenic temperature than at room temperature, but the breaking elongation of materials was lower.