铝发泡剂改性水泥基复合发泡材料的制备及性能研究

Preparation and properties of aluminum foaming agent modifiedcement-based composite foaming material

在硅酸盐水泥的基础上引入酚醛树脂,通过掺入不同含量(0,3%,6%和9%)(质量分数)的铝发泡剂,制备了铝发泡剂改性水泥基复合发泡材料。通过万能材料试验机、SEM和平板导热仪等,对该复合发泡材料的力学性能、微观形貌及导热系数等进行了分析。结果表明,随着铝发泡剂含量的增加,复合发泡材料的抗压强度呈现出先升高后降低的趋势,当铝发泡剂的含量为6%(质量分数)时,试样的抗压强度达到最大值,为7.2 MPa;随着铝发泡剂含量的增加,复合发泡材料的容重呈现出先降低后略微升高的趋势,当铝发泡剂的含量为6%(质量分数)时,试样的容重达到最小值,为217.4 kg/m^(3);随着铝发泡剂含量的增加,复合发泡材料的吸水率呈现出先快速上升再缓慢下降后快速上升的趋势,当铝发泡剂的含量为9%(质量分数)时,试样的吸水率达到最大值,为21.7%。SEM分析发现,未掺杂铝发泡剂的基体中气孔含量较少且分布不均,但大尺寸的气孔较多,随着铝发泡剂的掺入,气孔的数量明显增多且分布慢慢变得均匀,而大尺寸的气孔数量明显减少,孔壁处的结构变得更加紧密结实;随着铝发泡剂含量的增加,复合发泡材料的导热系数呈现出逐渐下降的趋势,当铝发泡剂的含量为6%和9%(质量分数)时,试样的导热系数开始缓慢降低,降低幅度仅为5.41%。由此可知,随着铝发泡剂的掺入,基体的保温性能均得到了提升,综合力学性能、容重、吸水率和导热系数等来看,铝发泡剂改性水泥基复合发泡材料中铝发泡剂的最佳掺量为6%(质量分数)。

On the basis of Portland cement,phenolic resin was introduced,and aluminum foaming agent with different contents(0,3wt%,6wt%and 9wt%)was added to prepare aluminum foaming agent modified cement-based composite foaming materials.The mechanical properties,micro morphology and thermal conductivity of the composite foam were analyzed by universal material testing machine,SEM and flat thermal conductivity meter.The results showed that the compressive strength of the composite foam increased first and then decreased with the increased of the content of aluminum foaming agent,when the content of aluminum foaming agent was 6wt%,the compressive strength of the sample reached the maximum value of 7.2 MPa.With the increased of the content of aluminum foaming agent,the bulk density of the composite foams decreased at first and then slightly increased,when the content of aluminum foaming agent was 6wt%,the bulk density of the sample reached the minimum value of 217.4 kg/m^(3).With the increased of the content of aluminum foaming agent,the water absorption of the composite foamed materials showed the trend of rapid rise,slow decline and rapid rise,when the content of aluminum foaming agent was 9wt%fraction,the water absorption of the sample reached the maximum value,which was 21.7%.SEM analysis showed that there were less and uneven pores in the matrix without al foaming agent,but more large pores,with the addition of aluminum foaming agent,the number of pores increased significantly and the distribution gradually became uniform,while the number of large-size pores decreased significantly and the structure of pore wall became more compact.With the increased of the content of aluminum foaming agent,the thermal conductivity of the composite foamed material showed a decreasing trend,when the content of aluminum foaming agent were 6wt%and 9wt%,the thermal conductivity of the sample begins to decreased slowly,and the reduction was only 5.41%.Therefore,with the addition of aluminum foaming agent,the thermal insulation properties of the matrix were improved,considering the mechanical properties,bulk density,water absorption and thermal conductivity,the optimum content of aluminum foaming agent in the modified cement-based composite foaming material was 6wt%.