Preparation And Properties Of Emulsion-Type Sizing Agent For Carbon Fiber

The Paper introduced the development and several main preparation approaches with respect to the sizing agents for carbon fiber in recent years. Two kinds of emulsion type sizing agents for carbon fiber which are especially aimed at tetraglycidyldiaminodiphenylmethane(TGDDM) epoxy resin and poly acrylonitrile-butadiene-styrene(ABS) resin were prepared through phase-inversion emulsification method. The optimal formula ratios for raw materials and preparation condition of the sizing agents were ascertained. Particle size and distribution test, centrifugal test, fourier transform infrared spectroscopy(FTIR), differential scanning calorimetry(DSC) test, abrasion resistance test, filament breakage test, stiffness test and interlaminar shear strength(ILSS) of fiber reinforced resin composites were carried out in order to study the properties of sizing agent and its effects on the handling ability of carbon fiber and the interfacial bonding strength for composites.The sizing agent emulsion aimed at TGDDM matrix was successfully obtained through phase-inversion emulsification method by using dodecylamine modified TGDDM resin as the film former agent. The optimal emulsifying process,(i.e., the mass ratio between compound emulsifier and modified TGDDM resin was 10:90, the emulsifying temperature was 50 ?, the emulsifying stirring rate was 11000 rpm), was established by using of contrast experiments and some relevant tests. The centrifugal tests and particle size analysis obtained indicated that the prepared sizing agent emulsion possessed excellent stability. DSC testing results demonstrated that the heat resistance of the self-made sizing agent was much superior to that of the sizing agent based on the traditional epoxy resin. After sizing treatment, the surface of the carbon fiber became smoother; the abrasion resistance time of the sized carbon fiber bundle reached 1765 times enhancing by 172.8 % compared with that of the desized carbon fiber bundle; the filament breakage of the sized carbon fiber was just 3.9 mg, decreasing by 9.9 mg compared with that of the desized carbon fiber. Therefore, the handling ability of the carbon fiber was greatly increased via sizing treatment. The ILSS of the sized carbon fiber reinforced TGDDM composite could reach 57.63 MPa, increasing by 29.16 % compared with that of the desized carbon fiber reinforced TGDDM composite(44.62 MPa). The results above revealed that the sizing treatment of carbon fiber could obviously improve the interfacial bonding strength between the carbon fiber and the TGDDM resin matrix.The emulsion type carbon fiber sizing agent especially aimed at ABS resin matrix was prepared through phase-inversion emulsification method. In the emulsion, the film former agent was poly acrylonitrile-butadiene-styrene(NSM) modified ABS resin and the emulsifier was OP-10. The optimal emulsifying process achieved by the contrast test was listed as follows. The suitable emulsifying temperature was 40 ?, the best emulsifying stirring rate was 9000 rpm, the appropriate mass ratio of emulsifier to film former resin was 3:10. After sizing treatment of carbon fiber, the hollows on the surface of carbon fiber was restored; The chemical structure of carbon fiber was significantly changed, generating plenty of functional groups and chemical links; The abrasion resistance time of the sized carbon fiber bundle was 2316 times, enhancing by 111.8 % in comparison with that of the desized carbon fiber bundle which was only 1093 times; The filaments breakage decreased from 11.7 mg to 2.7 mg. Accordingly, the handling ability of carbon fiber was dramatically ameliorated via sizing treatment. The ILSS of sized carbon fiber reinforced ABS composite could reach as high as 29.79 MPa, improving by 26.6 % in comparison to that of the desized carbon fiber composite(23.53 MPa). This result indicated that the interfacial bonding strength between carbon fiber and ABS matrix was distinctly increased by the sizing treatment of carbon fiber.