Study On Properties Of Maleimide Modified RTM Phenolic Resin And Composite Materials

At present,the domestic research and development of special ablation-resistant phenolic resin for nozzle expansion section has just started.The research level and research level of ablation-resistant phenolic resin synthesis process control,structural analysis and characterization and the relationship between composite material molding process and performance Compared with foreign countries,there is a big gap,and it is far from meeting the urgent needs of the development of models.It is urgent to break through the key technology of the preparation of highperformance ablation-resistant phenolic resins and develop new highperformance,low-cost resins to meet the needs of models.Demand.The main content of this paper is to develop modified phenolic resin series with interface synergistic enhancement,ablation resistance,high strength thermal insulation and other characteristics to solve the problems of single resin and lack of resin system designed according to the functional requirements of the existing nozzle composite materials.By means of molecular structure design,in-situ polymerization,and the affinity between polyimide and carbon fiber surface to enhance the interface between phenolic resin and fiber matrix,the composite mechanical properties were enhanced,and the processing technology of the composite was simplified.The curing mechanism and thermal stability of polyimide modified phenolic resin were studied to guide the setting of molding process parameters.To study the comprehensive properties of resin composites and establish a material characterization system corresponding to the use requirements of the materials.The main research contents are as follows:(1)The BDM/4-HPM modified phenolic resin with good thermal stability and high residual carbon rate was prepared through in-situ polymerization technology and process of phenolic resin,and the curing mechanism and curing pyrolysis behavior of the modified resin were studied.(2)By selecting appropriate RTM molding process parameters,prepare molded BDM/4-HPM modified phenolic resin carbon fiber composites,and test the porosity,mechanical properties,thermal conductivity and ablation resistance of the phenolic composites.The introduction of maleimide can lower the porosity of the composite material,improve the affinity of the resin and the inert carbon fiber,increase the infiltration with the matrix resin,and significantly improve the mechanical properties and ablation resistance.