| Fiberglass is an environment friendly inorganic non-metallic materials with excellent performance,which is widely used in various fields.Fiberglass is also one kind of indispensable reinforcement materials of the aerospace,defense,civil and other industries.Sizing agent is the core of glass industry,which plays an important role in lubricating and protecting glass fiber yarns,giving glass fiber strand integrity and joint stock property.Both to meet the glass fiber post-processing operations,and enhance the interfacial adhesion between glass fiber and epoxy resin matrix.In this experiment,corn starch was selected as the experimental raw material,and the starch was chemically modified by epoxy resin.The effects of infrared,viscosity,surface tension,contact angle,fracture strength and morphology were analyzed to investigate starch sizing agent and its effect on glass fiber and the composite materials.The interfacial properties of the composites were also studied.Properties of different composites were compared by means of fracture section scanning,mechanical properties and thermal properties.In this paper,the optimal reaction process of the system is determined by single factor and orthogonal analysis,which solves the difficult problem of complex process such as incineration when the textile type sizing agent is used for reinforcement.The performance test results show that the stability of starch infiltration,coating effect,breaking strength and so on have greatly improved.（1）Epoxy resin E-44 modified corn starch system: Corn starch starch 20 g,epoxy resin E-44 2 g,NaOH 2 g,reaction temperature 95 o C,reaction time 8 h.The performance of the wetting agent is the best under the experiment conditions above.The viscosity,surface tension and contact angle of the sizing agent were 18.0 m Pa·s,51.90 m N·m-1 and 38.93°,respectively,and after infiltration the breaking strength of glass fiber yarn has greatly improved,with breaking strength value of 0.42 N·tex-1.（2）Epoxy resin E-51 modified corn starch system: Considering the methods inliterature to prepare of the modified corn starch in,the optimum conditions for modified corn starch were obtained by single factor and orthogonal experiment.Corn starch starch 20 g,epoxy resin E-51 10 wt.%,NaOH 2 g,and reacted at 95° C for 8 h to prepare the optimal sample.The viscosity,surface tension and contact angle of the sizing agent were 7.50 mPa·s,40.05 mN·m-1and 32.63°,respectively.Sizing agent was more effectively spread on the surface of glass fiber.The glass fiber yarn mechanical properties have greatly improved,with the breaking strength of 0.45 N·tex-1.（3）Epoxy fiberglass composites system: Considering the methods of enhancing the performance of composite interface in literature,epoxy glass fiber composites were fabricated with the best sample of epoxy resin modified starch system.The results show that after modified the interfacial adhesion between glass fiber and epoxy resin has been improved,and the mechanical properties and thermal properties of the epoxy-based glass fiber composite have also been improved.E-44 epoxy resin system,compared with pure resin,after epoxidized modification,tensile strength of composites was increased by 60%,bending strength was increased by 22%,impact strength increased by 72%.Besides,the glass transition temperatures was increased by 4.23 o C.E-51 epoxy resin system,compared to pure E-51 epoxy resin,after epoxidized modification,tensile strength of composites was increased by 33%,the bending strength increased by61%,the impact strength was increased by 73%.Furthermore,the glass transition temperatures was increased by 7.31 oC.The results of epoxy glass composites show that after modification,the bonding property of glass fiber composite interface has been improved,and the mechanical properties and thermal properties have also been greatly improved.The E-51 system was superior to the E-44 system,indicating that the epoxy resin E-51 was more suitable for the field of starch epoxidation and epoxy-based glass fiber composites.This study provides some reference for the deep research of reinforced infiltrating agent and glass fiber composite material. |
PDF Full Text Request