Design,preparation And Properties Of Flame Retardant Epoxy Coating Materials Based On Hollow Carbon Spheresabstract

Epoxy resin(EP)has good corrosion resistance,mechanical properties,dimensional stability,and is widely used in coatings,composites,adhesives and electrical industries.However,EP is flammable and releases a large amount of toxic fumes such as carbon monoxide,aromatic compounds,and hydrocarbons,which greatly limit the wide application of EP.Therefore,the design and preparation of new fire-safety EP composite epoxy coating materials have key social needs.In this paper,three kinds of hollow carbon spheres,HCS@Cu2O,HCS@Ni and HCS@ZnO,were synthesized by using copper acetate,nickel acetate,zinc acetate and hollow phenolic resin spheres as raw materials to support transition metals or oxides by blending and calcination.The corresponding flame retardant EP composites were prepared,and the effect and mechanism of HCS@Cu2O,HCS@Ni,HCS@ZnO on the combustion properties and thermal degradation properties of EP composites were studied.The main research contents and conclusions are as follows:1.Research on HCS@Cu2O flame retardant EP.The study found that HCS@Cu2O played a great role in flame retardant and smoke suppression in the EP system.The CCT results showed that HCS@Cu2O can reduce the heat release and smoke release of EP;the peak heat release rate(p HRR)of the EP/HCS1.00 sample was 984.2k W/m2,and the total smoke release(TSR)was 3093.7m2/m2.Adding HCS@Cu2O can reduce the heat release and smoke release of EP;the p HRR of EP/(HCS@Cu2O)1.00 sample was reduced to 660.8k W/m2,and its TSR was reduced to 330.3m2/m2.The maximum CO release rate of EP was 0.39 g/s,and the maximum CO release rate of EP composites with 1.00wt%HCS@Cu2O added was 0.06 g/s,which was 84.6% lower than that of EP.At the same time,the residual carbon residue of EP/(HCS@Cu2O)composites will also increase with the addition of HCS@Cu2O,and the final residual carbon residue of EP/(HCS@Cu2O)1.00 was the largest among all samples,the value of it was 13.75%,which was 7.32% and 5.94% higher than that of pure EP composite and EP/HCS1.00,respectively.2.Research on HCS@Ni flame retardant EP.It was found that Ni improved the thermal stability and smoke suppression performance of the EP system.The p HRR of the EP composite containing 1.00wt% HCS@Ni was the lowest with a value of 716.6k W/m2,which was 27.2% lower than the p HRR of the EP/HCS1.00 sample and lower than that of the pure EP material decreased by 65.9%.In addition,HCS@Ni enhanced the smoke suppression performance of EP composites.The TSR of pure EP was 3275.7m2/m2,and the TSR of EP composite with 1.00wt% HCS added was 3093.7 m2/m2.The TSR of EP/(HCS@Ni)0.25 was 2650.9 m2/m2,which was 19.1% and 14.3% lower than that of EP and EP/HCS1.00,respectively.The maximum CO release rate of the EP composite with the addition of 1.00wt% HCS@Ni was 0.07 g/s,which was 82.1% lower than that of pure EP.This was because the HCS in HCS@Ni blocks the entry of external O2,and Ni can catalyze the conversion of CO to CO2.Therefore,HCS@Ni can reduce the CO generated during the combustion of EP composites and reduce the toxicity of EP.3.Research on HCS@ZnO flame retardant EP.The results showed that HCS@ZnO can improve the densification of the carbon layer of EP,and reduce the heat generated during EP combustion and the emission of flue gas.HCS@ZnO can improve the flame retardancy of EP.The p HRR of EP/(HCS@ZnO)1.00 was reduced to 834.0k W/m2,which was 15.0% lower than that of EP/HCS1.00.When the addition amount of HCS@ZnO was1.00wt%,the total heat release(THR)of the EP composite was 150.2 MJ/m2,the lowest value among all samples.It showed that HCS@ZnO reduced the thermal hazard of EP composites.Compared with pure EP,the residual amount of carbon layer of EP composites with HCS@ZnO was increased,and the residual amount of carbon residue of EP/(HCS@ZnO)1.00 was the highest among all samples,and the value of residual carbon residual amount was 13.75%,which was 7.31% higher than that of EP.Compared with pure EP,the surface of the carbon layer of the EP/HCS composite had a few cracks,while the surface of the carbon layer of the EP/(HCS@ZnO)composite was complete.And the electron microscope pictures showed that the carbon residue of EP/(HCS@ZnO)had good compactness.The above results showed that HCS@ZnO can improve the thermal stability and carbon residue of EP composites,and the flame retardant effect of HCS@ZnO was better than that of HCS.