Preparation And Performance Of The Emulsion Type Sizing Agent Made Of Epoxy Resin For Carbon Fibers

Carbon fibers have outstanding properties such as high specific strength,high modulus,high temperature resistant,wear resistant,corrosion resistanc etc,which as a reinforcement matertials have been applied in aerospace,medical,national defense,industrial equipment,professional sports supplies and transportation equipment.However,the surface of carbon fibers is inert and it is easy to produce wool and even broken wires in the process of preparation and processing,which ultimately affects the properties of carbon fibers and the performance of their products.Therefore,it is necessary to treat carbon fibers by using the sizing agent before they are collected.Sizing agent plays an important role in carbon fibers,which is an important research direction in the field of carbon fibers.In this thesis,polyester polyols were firstly synthesized by using bisphenol A polyoxyethylene ether(BSA-20),maleic anhydride(MA)and polyethylene glycol 1450(PEG 1450)as raw materials;Polyester polyols modified epoxy resin were prepared by using the epoxy resin(E-20)and polyester polyols;The emulsion type sizing agent was prepared by using polyester polyols modified epoxy resin as an important component.We study the optimal preparation process for the sizing agent emulsion and formulate three test programs because of their stable performance.Second,the performance of the three self-made sizing agents was tested and then compared with the performance of Japanese sizing agent(SAJ)and domestic sizing agent(SAC).Finally,carbon fibers were sized by 5 kinds of sizng agents to study the effect of sizing agent on the apparent properties of carbon fibers(surface morphology,sizing rate,filament volume,sag,width)and interlaminar shear strength(ILSS)of carbon fiber reinforced composites.Results of the thesis indicate that:(1)The optimum process of polyester polyol:raw material molar ratio:BSA-20:MA:PEG1450=7:6:1;tetraethylammonium bromide as catalyst,0.05%wt;first step and two-step esterification temperatures were 160 ? and 180 ?,respectively,and the reaction times were 4h and 8h,respectively.(2)The optimum addition amount of epoxy resin(E-20)in polyester polyol modified epoxy resin is 25%wt.(3)Three test programs with stabilized emulsion properties were identified.E-51 epoxy resin sizing agent----polyester polyol modified epoxy resin 10g,triethanolamine 2g,triphenylphosphine 0.05g,E-51 epoxy resin 14g,nonylphenol polyoxyethylene ether(NP-12)2g,polypropylene glycol glycidyl ether(DER732)1g;E-20 epoxy resin sizing agent----polyester polyol modified epoxy resin 10g,triethanolamine 2g,triphenylphosphine 0.05g,E-20 epoxy resin 8g,nonylphenol polyoxyethylene ether(NP-12)2g,polypropylene glycol glycidyl ether(DER732)2g;SA-1 composite epoxy resin sizing agent----polyester polyol.modified epoxy resin 10g,triethanolamine 2g,triphenylphosphine 0.05g,E-51 epoxy resin 4g,E-20 epoxy resin 5g,nonylphenol polyoxyethylene ether(NP-12)2.4g,polypropylene glycol glycidyl ether(DER732)2.4g;(4)Compared with the performance of epoxy resin-based domestic sizing agent(SAC)and Japan sizing agent(SAJ),the research shows that three kinds of self-made epoxy resin sizing agent emulsions have reached the performance of domestic sizing agent in various aspects,in some indicators,even surpassed the Japanese sizing agent.(5)Infrared analysis showed that three kinds of self-made sizing agent emulsion and Japanese sizing agent SAJ have more similarity in the primary structure(chemical composition);Gel permeation chromatography analysis founded that the relative molecular masses of SA-1 and SAJ was similar.,the two sizing agents may also have similarities in secondary structure(relative molecular mass).The self-made sizing agent SA-1 and Japanese sizing agent SAJ may be similar in material composition.(6)After the sizing,the surface morphologies of the carbon fibers on the SAC sizing agent showed local agglomeration and uneven sizing,and the remaining four sizing agents could coat the carbon fibers.In terms of carbon fiber processing performance,the SAC sizing agent and the SAJ sizing agent performed are similar,and the self-made sizing agent SA-1 had similar performance to both.The interlaminar shear strength(ILSS)of their composites were also similar,being 88.4 MPa,86.9 MPa,87.8 MPa,respectively.Compared with unsized carbon fiber reinforced composites,SAC,SAJ,and SA-1 increased by 21.76%,19.70%,and 20.94%,respectively.