Structurally Modified Phenolic Resin-based High Wear-resistant Composite Material

High-performance polymer-based composites are widely used due to their unique advantages such as high strength,high hardness,high plasticity,low cost,and low quality.However,with the continuous advancement of science and technology and the increasing needs of people's lives,the performance and life of polymer-based composite materials still have many problems in many harsh working environments.For example,parts such as pump bodies,mixer blades,and pipelines in marine engineering that work in high-wear environments.These parts have been subjected to erosion and wear by water,mud,sand and other media for a long time.Abrasive wear results in severe loss of material performance to failure,and its life is often short,some only a few months.Due to the unavoidable wear and tear problems in the industrial production process,the key parts of the equipment have a short service life and require frequent maintenance and replacement,which causes great losses to the industrial economy and causes serious waste of resources.Therefore,polymer-based abrasion-resistant composites with better performance have become one of the hot topics of current research.In this paper,phenolic resin is used as the matrix resin of polymer-based composite materials,and silicon carbide is used as the reinforcing material to prepare phenolic resin-based high wear-resistant composite materials.In order to solve the shortcomings of traditional phenolic resins such as poor toughness and insufficient heat resistance,this paper first synthesized two modified phenolic resins with excellent heat resistance and toughness,and compared the performance to select the most suitable modified resin as the matrix resin.The main research contents of abrasion-resistant composite materials are as follows:(1)The molecular design method is used to introduce the modifier p-xylylene dimethyl ether and 4,4'-dichlorodiphenyl sulfone into the phenol structure,and the obtained modified phenol and paraformaldehyde are added through The p-xylylene dimethyl ether modified phenolic resin and 4,4'-dichlorodiphenylsulfone modified phenolic resin were prepared by condensation.The structure of the modified phenolic resin was verified by infrared spectrum and nuclear magnetic hydrogen spectrum.Thermal performance,aging resistance,and mechanical properties were compared in terms of performance characteristics of ordinary phenolic resins,p-xylylene dimethylether modified phenolic resins and 4,4'-dichlorodiphenylsulfone modified phenolic resins.The results show that : The temperature at which 5% loss of p-xylylene dimethyl ether modified phenolic resin is 366.37 ?,the temperature of4,4'-dichlorodiphenyl sulfone modified phenolic resin is 364.52?;The peak temperature of thermal decomposition of ether-modified phenolic resin is 541.06?,and that of 4,4'-dichlorodiphenyl sulfone-modified phenolic resin is 540.35?;At20%,the maximum load deformation temperature of the modified phenolic resin is236.4?,and the amount of the modifier 4,4'-dichlorodiphenylsulfone is phenol.When the amount is 8%,the maximum load deformation temperature of the modified phenolic resin is 240?;after 96 hours of heat aging,the bending strength loss of the p-xylylene dimethyl ether modified phenolic resin is 23.6%,4,4'-The dichlorodiphenylsulfone modified phenolic resin is 19.0%;the p-xylylene dimethyl ether modified phenolic resin has an impact strength loss of 30.00%,and the4,4'-dichlorodiphenylsulfone modified phenolic resin is 25.00%.Based on the comparison of the above data,4,4'-dichlorodiphenyl sulfone,which has both heat resistance and toughness,was selected as the matrix resin of the high wear-resistant composite material.(2)4,4'-dichlorodiphenylsulfone-modified phenolic resin was used as the matrix resin for the composite material,silicon carbide was used as the reinforcing material,and a curing agent,a silane coupling agent,and molybdenum disulfide were added to prepare 4,4 '-Dichlorodiphenylsulfone modified phenolic resin-based abrasion-resistant composite material.The tensile strength,flexural strength,compressive strength,and abrasion rate under abrasive erosion of modified phenolic resin-based composites were tested.The results show that when the curing agent content is 10%,the mechanical properties of the composites are the highest.The tensile strength is 19.5 MPa,the bending strength is 24.31 MPa,the compressive strength is 60.37 MPa,and the wear rate of the composite is at least 3.76 mg / s.When the content of KH550 is 2.5%,the mechanical properties of the composite are highest:The tensile strength is 25.14 MPa,the bending strength is 31.50 MPa,and the compressive strength is 72.82 MPa.At the same time,the wear resistance is the best:the wear rate is at least 3.02 mg / s;when the content of molybdenum disulfide is 3%,the composite material wears.The lowest rate is 2.81 mg / s.Best abrasion resistance.