| For gas adsorption materials,the structure and characteristics of the carrier determine the properties of the composite materials.Compared with other carriers,spherical polyacrylate materials have the advantages of low density,high porosity and easy modification of pore surface.However,the spherical polyacrylate matrix prepared by suspension polymerization has some problems,such as low yield,unconcentrated particle size distribution and low strength.Therefore,in order to improve its comprehensive performance,spherical polyacrylate carrier materials were synthesized by the drop ball method.The main research contents are as follows:(1)Spherical polytert-butyl acrylate carrier material was prepared by emulsion polymerization and drop ball method.The effects of emulsion viscosity,polymerization temperature and mechanical parameters on the properties of the materials were studied.Based on the optimal operating conditions,spherical polytert-butyl acrylate carrier materials were prepared.The total yield of the material was 59.7%,in which 75.9%of the spherical particles were in the range of 0.42mm-0.85mm,the mechanical strength was30 MPa,the bulk density was 0.16g/cm~3,and the pore size was mainly distributed in the range of 0.8-2.5μm,with an average pore size of 1.53μm.It has developed and interconnecting pore structure,which is an excellent carrier for gas adsorption materials.(2)Spherical polytert-butyl acrylate carrier material containing nano-metal oxides was prepared by adjusting emulsion composition and drop ball method.The effect of droplet position and metal oxide content on material synthesis was investigated.When the amount of nanometer zinc oxide is 2.5 g,the performance of zinc oxide/polytert-butyl acrylate material synthesized by the way of drop ball under the liquid level is the best.The results show that the total yield of the material is 72.1%,the material with particle size in the range of 0.4-1.0mm accounts for 92.3%,the average mechanical strength is48.0MPa,and the bulk density is 0.26g/cm~3.The pore size of the material is mainly distributed in 0.1-1.0μm,and the average pore size is 1.03μm.When the amount of nano-silica is 2.7g,the performance of nano-silica/polytert-butyl acrylate carrier material synthesized by dropping ball under the liquid level is the best.The specific performance is:the total yield of the material is 74%,the particle size in the range of 0.4-1.0mm material accounted for 87.2%,the average mechanical strength of 51.0MPa,the density of 0.32g/cm~3,with 0.1-1.0μm aperture,the average diameter of1.46μm.The experimental results show that the two materials exhibit good performance parameters,and the structure is stable at the working temperature(60-120℃).However,due to the addition of nano-metal oxides,the average pore diameter of the materials will be reduced,which will affect the adsorption capacity of the subsequent adsorption materials to a certain extent.(3)Two kinds of spherical polytert-butyl acrylate and zinc oxide/polytert-butyl acrylate were studied in small scale,the scale of amplification was about 300 times.When the stirring rate of emulsion kettle was 120 r/min,spherical polytert-butyl acrylate materials with yield of58.71%,average mechanical strength of 27.0 MPa,bulk density of 0.18 g/cm~3and particle size of 0.5-0.9 mm were synthesized.And spherical zinc oxide/polytert-butyl acrylate materials with yield of 69.84%,average mechanical strength of 45.0 MPa,bulk density of 0.28 g/cm~3,particle size mainly distributed in the range of 0.6-1.0 mm.Tests show that the two materials can maintain structural stability in the operating temperature range(60-120℃).After 10 h of dynamic fluidization in a fluidized bed,the wear rate of spherical polytert-butyl acrylate is 0.1 wt.%·h-1.The wear rate of spherical zinc oxide/polytert-butyl acrylate material is 0.06 wt.%·h-1.It has good mechanical properties,thermal stability and wear resistance,and basically eliminates the boundary effect caused by amplification. |
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