Preparation Of Double Bonded Starch And Its Effect On Interfacial Properties Of Glass Fiber Composite

Glass fiber is a common inorganic nonmetallic material,because of its high strength,anti-corrosive,good insulation and other unique properties,often used as a reinforcement to prepare composite materials.However,due to its smooth surface and not resistant to friction,resulting in the phenomenon of flying wire in the application.For the prepared glass fiber composite material,although its performance has been significantly improved,the bonding strength of the interface is low,easily to become a stress concentration source to be destroyed,thereby affecting the overall performance of composite materia ls.In this paper,starch was used as raw material to prepare modified starch.we studied the overall performance of the modified starch,used as the film-forming agent.Then,the glass fiber composite was prepared by using the glass fiber sized with film-forming agent.The interface properties of the composites were investigated.The properties of modified starch emulsion and infiltration yarn were characterized by FT-IR,NMR,viscometer,surface tension meter,contact angle tester and other means.In addition,the interface compatibility of glass fiber and vinyl ester resin(VE)was investigated by mechanical property test,SEM,thermal analysis and other methods.The main contents and results are as follows:Through chemical modification of starch by all yl glycidyl ether,the optimum preparation conditions were as follows: AGE content 15%,NaOH content 7.5%,reaction temperature 95 ?,reaction time 10 h.In this condition,the effect of modified starch film-forming agent on the glass fiber was better than that of the original starch emulsion,and the mechanical properties and stiffness of the yarn were improved obviously.Using 4-vinyl epoxy cyclohexane to modify the starch to prepare a series of modified starch film forming agent.The results showed that when the content of 4-vinyl epoxy cyclohexane was 10%,the NaOH content was 4%,the reaction temperature was 95 ? and the reaction time was 12 h,the modified starch film forming agent and infiltration yarn have a excellent performance.The interfacial properties of glass fiber composites were studied by using glass fiber and different kinds of infiltration yarns to enhance the vinyl ester resin.The results show that,the glass fiber which sized with two kinds of modified starch film forming agent,their interfacial bonding str ength and mechanical properties of the composite are better than those of the glass fiber and the original starch type.This is mainly because the carbon-carbon double bond on the surface of the glass fiber can participate in the copolymerization of the resin matrix,and strengthen the interface adhesion.In summary,we modified the starch,which was used in the glass infiltration,and prepared glass fiber composite.Through this treatment,the bonding strength of the composite material has greatly improved.