蔗糖基泡沫碳材料前驱体成形的影响因素研究

Study of Factors Influencing Formation of Sucrose-based Carbon Foam Precursors

采用凝胶注模成形法制备蔗糖基泡沫碳前驱体,重点研究单体引发过程及蔗糖基碳前驱体成形过程。通过凝胶时间测定分析单体的含量、交联剂与单体的配比、引发剂的用量以及聚合反应温度来对凝胶过程的影响,通过弯曲强度测试及扫描电镜分析不同交联剂与单体配比下凝胶注模成形的蔗糖碳前驱体的坯体强度及微观结构。结果表明:丙烯酰胺质量分数28%,N,N-亚甲基双丙烯酰胺质量分数8.4%,引发剂过硫酸铵质量分数2%,50℃的聚合温度下,体系的凝胶时间可以控制在60~130s之间,满足凝胶注模成形所需要的操作时间。上述单体聚合条件下,添加蔗糖50g、造孔剂120 mL,制备的前驱体弯曲强度为0.46 MPa,SEM图像显示前驱体当中的造孔剂颗粒均匀,完整性好,同时蔗糖及凝胶包裹在造孔剂周围,连接强度高。

Sucrose-based carbon precursors were prepared by gel-casting method,focusing on monomer initiation process and sucrose-based carbon precursors molding process.The influence of monomer content,cross-linker-monomer ratio,initiator dosage and polymerization temperature on the gelation process was analyzed by gel time measurement.The strength and microstructure of sucrose-based carbon precursors molded by gel-casting were analyzed by bending strength test and scanning electron microscopy with different cross-linker-monomer ratio.The experimental results showed that the gelation time of the system could be controlled between 60~130 s with 28%of acrylamide,8.4%of N,N-methylenebisacrylamide,2%of ammonium persulfate as initiator and a polymerization temperature of 50℃,which satisfied the operation time required for gel-casting.Under the above monomer polymerization conditions,50 g sucrose and 120 mL pore-forming agent were added,and the bending strength of the prepared precursor was 0.46 MPa.SEM images showed that the pore-forming agent particles in the precursor were uniform with good integrity,while sucrose and gel were wrapped around the pore-forming agent with high connection strength.