聚合物改性粉煤灰制备多孔复合材料及其性能研究

SYNTHESIS AND PROPERTIES OF POLYMER MODIFIED FLY ASH BASED POROUS COMPOSITES

制备了高掺量粉煤灰为基质的聚乙烯醇/纤维素复合多孔材料。该复合材料制备过程简单易行,不需高温高压。通过XRF、XRD、FT-IR、SEM以及压汞法对该粉煤灰复合材料进行了表征和结构分析,探索了原料混合比例、干燥温度对样品结构和性能的影响。研究发现:聚乙烯醇可以有效提高该复合材料的无侧限抗压强度,纤维素可有效改善材料的孔隙结构;材料的孔隙主要来自水分蒸发过程中的气泡聚合,在外部不加压的条件下制备样品,需控制干燥温度对样品内部孔隙结构的影响。当粉煤灰含量为80%,聚乙烯醇含量为10%,纤维素含量为10%时,复合材料具有较好的孔隙率、孔隙结构、抗压强度和吸水性及保水性。有一定强度的以粉煤灰为基质的亲水性材料也适合作为吸附材料或滤料,未来可以进一步通过改善材料内部结构,以及活化功能性官能团以提高材料的综合性能,为粉煤灰的综合利用拓展途径。

In this research,polyvinyl alcohol/cellulose composite porous materials with high content of fly ash were prepared.The preparation process of the composite was simple,without requirement of high-temperature or high-pressure conditions.The characterization of the fly ash composites was analyzed via XRF,XRD,FT-IR,SEM,and mercury porosimetry.The effects of the mixture ratio of raw materials and drying temperature on the properties of the samples were explored.It was found that PVA could effectively increase the unconfined compressive strength of the composites,and cellulose was useful to improve the porous structure of the composites.The pore structure of the composites mainly came from the bubble polymerization in the process of water evaporation.The drying temperature was an essential factor that had influence on the pore structure,when the samples were prepared under the condition without external pressure.When the content of fly ash was 80%,polyvinyl alcohol was 10 wt%and cellulose was 10 wt%,the composite had good properties in porosity,pore structure,compressive strength,water absorption and water retention capacity.The comprehensive performance of the fly ash-based materials could be further developed by improving the internal porous structure and activation of the chemical functional groups.Further research needs to be conducted,to make the hydrophilic fly ash composites with certain compressive strength and provide good alternative for the utilization of fly ash.