Research On The Properties Of Glass Fiber Mesh/Fly Ash/Thermoplastic Polyurethane Composite Materials

Under the guidance of the basic national policy,local governments and enterprises are actively implementing the big environmental protection project of transforming from“black pollution” to “green industry” to reduce,recycle and reuse the coal measure solid waste—fly ash,which has large output,large stock and heavy environmental impact.There is discontinuity and instability in new energy power generation(wind power and photovoltaic).Burning 1 ton of coal will produce 250～300 kilograms of fly ash coal-fired power capacity reduction,which is not realistic at present.So the comprehensive utilization of fly ash to turn waste into treasure is imminent.By analyzing the physicochemical properties of fly ash,it is found that fly ash can be used as polymer material filler or substitute to improve the performance of composite materials.Therefore,this paper takes thermoplastic polyurethane as the base material,fly ash as the filling material,glass fiber mesh as the reinforcement body,the preparation of two component and three component composite materials,through surface modification to solve the interface compatibility and poor adhesion between fly ash and polyurethane,glass fiber mesh and polyurethane;The structural morphology,mechanical properties and flame retardant properties of the composites were studied,and the optimum ratio of modifier and fly ash was determined.By SEM morphology,contact Angle,EDS spectra and strength analysis,the modification scheme with the complex ratio of silane coupling agent and titanate coupling agent 1:1 successfully completed the chemical coating of fly ash surface,realized the transformation from hydrophilic to oilophilic,and built a molecular bridge for fly ash evenly dispersed in polyurethane matrix and improved interface adhesion.The change law of tensile strength and tearing strength of fly ash filled TPU composite prepared by the optimal modification scheme is that the strength first increases and then decreases with the increase of the filling amount,and the hardness of the composite increases with the increase of the filling amount.The intersection point of the three laws is20%,which is the optimal filling amount of fly ash.The filling of 20% fly ash changed the thermal behavior of the thermoplastic polyurethane and reduced its combustion performance.The peak heat release rate(PHRR)decreased by 35.6%,the smoke release rate(SPR)decreased by 22.22%,and the residual carbon rate reached 18.03%.The silane coupling agent KH-570 modified glass fiber mesh to generate stable Si-OSi bond without weakening the strength of glass fiber.The analysis of tensile strength and section morphology of the modified glass fiber mesh / 20% modified fly ash / 80% TPU reinforced composites shows that the tensile strength of the composites increases first and then decreases with the increase of the mass fraction of silane coupling agent,and the optimal mass fraction of silane coupling agent is 2 wt %.The addition of glass fiber mesh with flame retardant further improves the flame retardant performance of the composite material,reduces the heat release rate,smoke release rate and gas volume,delays the ignition time,increases the amount of carbon residue,and effectively prevents the transfer of heat,oxygen and flammable volatiles.Therefore,fly ash,glass fiber mesh applied in thermoplastic polyurethane and other polymer materials,not only play a good strengthening and toughening,improve the effect of flame retardant,but also realize the fly ash waste into treasure,reduce the cost of composite materials.