The Study Of Hygrothermal Aging For Basalt Fiber/epoxy Composites Modified By CeCl₃

Fiber reinforced polymer composites are widely used in the important area,such as aerospace,automotive,machinery and so on.Because of their high specific strength,high specific modulus,fatigue resistance and other excellent properties.But composite materials in the processing,storage and use process,it will be affected by environmental factors（such as air,water,sunshine,and the change of environmental temperature）,the effects of these environmental factors can make composite materials performance degradation and aging,which limit the performance of composite materials in the process of application.In this paper,basalt fiber was used as reinforcing material due to it is environmental protection material and it has high performance,it’s surface was modified with rare earth solution（CeCl₃）in order to improve the interface bonding performance of composite materials.Then simulating hot and humid environment in the laboratory,the property of wet and heat aging of basalt fiber/epoxy resin composite materials which was modified by rare earth or not were studied by weight method,static mechanical performance test,SEM and FT-IR analysis in this condition.On the above foundation,the wet and heat aging mechanism of the composite materials has been discussed.The conclusion summarized as follows:1.The application of appropriate concentration of CeCl₃ solution can improve the bonding performance of composite materials,so as to improve the mechanical properties of composites.However,when the content of rare earth in the solution is too high,the interface bonding and mechanical performance of composite materials are beginning to decline.2.Water absorption curve of composite materials in hot and humid environment is in line with Fick two stage water absorption model.The tensile strength,bending strength and ILSS of the composites decreased after wet and heat aging.The main reason for mechanical performance degradation of composite materials was caused by moisture absorption.The faster the moisture rate,the greater the mechanical properties of the composites decreased.The interface bonding performance of the composites was improved by CeCl₃ modification,which can effectively prevent the spread of the water molecules,to enhance anti-aging performance of composite materials.But when the modified solution which was acted on basalt fiber has excessive amounts of rare earth,the anti-aging performance of composites began to decline3.By infrared spectra of composite materials after aging can be found that the active group absorption peak intensity of composites modified by CeCl₃ was higher than before.This shows that the rare earth solution can make composites has more active group,so improve the interface bonding properties of modified composites,which can reduce the decline of composites mechanical performance caused by wet and heat aging.4.Through SEM to observe tensile fracture of composite materials after aging prove that the application of CeCl3 solution make fiber surface has more resin adhesion in composite materials,this treatment can enhance the bonding properties of the interface,effectively prevent the entry of moisture,reducing the moisture absorption of composites,finally improve the anti-aging properties of the composites.But when the concentration of rare earth solution was too high,the resin on the surface of fiber gathered into large lumps,which lead to the organization is not uniform in the interface of composites,it weaken the bonding performance of the composites,therefore the falling range of mechanical properties of composites was getting large.