以聚氨酯泡沫为模板,糠醇为碳源,采用模板法制得块状泡沫炭材料,扫描电镜(SEM)观察发现:产品是由大孔组成的、具有网状结构的多孔材料。研究了不同炭化终温对产品形貌、残炭率和体积收缩率的影响;考察了对模板聚氨酯泡沫进行NaOH水解预处理的条件,即水解时间、水解温度和碱液浓度对模板及产品结构的影响。结果表明,模板的预处理去除了聚氨酯泡沫闭孔上的隔膜,提高了泡沫的浸渍能力,制得了具有更高开孔率、残炭率以及体密度的产品,说明模板预处理是改善产品结构和性能的有效手段。
Monolith-like carbon foams were prepared via a template method using polyurethane foam as template and furfuryl alcohol as carbon precursor. SEM examinations revealed that the as-obtained carbon foams had an interconnected structure and a large porosity made up of macrospores. The effect of carbonization temperature on the morphology, carbonization yield and volume shrinkage of the products was investigated. The polyurethane foam was pretreated with alkaline solution based on its hydrolysis characteristics. The influence factors, such as time, temperature and alkali concentration were studied. The polymers in the closed-cell of the polyurethane foam were removed and the impregnation ability of the template was enhanced after the pretreatment. The carbon foam with higher open porosity, carbonization yield as well as bulk density could be obtained. The results demonstrated that the pretreatment was efficient and necessary in order to improve the structure and properties of the carbon foam synthesized by the template method.