| China’s resource characteristics of "coal-rich,oil-poor and gas-poor" have determined that coal is still the main energy source.However,the gasification ash produced by coal gasification is not effectively treated for a long time,which has become one of the important factors restricting the sustainable development of coal chemical industry.How to effectively realize the resource utilization of gasification ash slag is an important research topic that needs to be broken through urgently.In this paper,we take coal gasification fine slag(CGFS)as the research object,make it as the filler of polyurethane foam(RPUF),analyze the influence of filler particle size,addition amount and foaming multiplier on the pore structure of the composite material,and further study the comprehensive performance of the composite material according to the pore structure characteristics.The following main conclusions were drawn.It was found that the large particle size CGFS was mainly placed between the bubble pores of the composites after the composite with RPUF,and the uniformity and integrity of the bubble pores were poor.After the small particle size CGFS is compounded with RPUF,the vesicle structure gradually tends to be uniform and complete,and the presence in the composite mainly includes the following three ways:1,adhering to the wall and wall pores by means of adhesion;2,part of the small particle size CGFS can be encapsulated and eventually cured inside the vesicle wall;3,part of it exists in the form of half encapsulation and half exposure.With the reduction of filled CGFS particle size,the overall mechanical properties of the composites are improved.A small amount of CGFS addition can make the composites maintain a more complete structure.When the addition amount of CGFS was 10% and 15%,the bubble pores showed obvious breakage and the pore size became uneven,and when the addition amount reached 20% and 25%,the bubble pore structure tended to be stable.With the increase of CGFS addition,the ultimate oxygen index of the composites was improved,and when the CGFS addition amount reached 25%,the ultimate oxygen index of the composites was increased from 18.75% of the blank sample to 20.40%.The study of the flame retardant mechanism revealed that the carbon layer produced during the combustion process of the composites with CGFS addition was more dense and stable,which effectively prevented the further combustion of the composites.The results of the open flame combustion test also showed that the composites still had the ability to sustain combustion in air after filling with CGFS,but the sustained combustion time was significantly shortened with the increase of CGFS addition.the results of TG(thermogravimetric)analysis showed that CGFS did not affect the initial reaction temperature of the composites,but could reduce the overall pyrolysis rate,and the results of FT-IR(infrared)also showed that that there is only a simple physical composite between CGFS and RPUF.With the increase of foaming multiplicity,the blister breakage of the composite deepens and the pore size increases significantly,which makes the mechanical properties of the composite greatly reduced,but still can meet the requirements of the application.The increase of low thermal conductivity gas in the bubble pore and the decrease of thermal conductivity of solid phase can reduce the thermal conductivity to0.038 W/m·k when the CGFS addition is 20% and the foaming multiplicity is 26.9.Figure [45] Table [14] Reference [110]... |
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