蜜胺-酚醛树脂-甲醛基有机气凝胶纳米孔在裂解过程中的稳定性研究  

Stability of mesopores in organic aerogels produced from melamine,phenolic resole and formaldehyde in pyrolysis

作　　者：张睿[1] 李雯[2] 胡子君[3] 张琢[1] 高楠[1] 钱惠春[1] 凌立成[2] 

机构地区：[1]上海应用技术学院材料工程系,上海200235 [2]华东理工大学化学化工学院化学工程国家重点实验室,上海200237 [3]航天材料工艺研究所,北京100076

出　　处：《新型炭材料》2009年第1期23-27,共5页New Carbon Materials

基　　金：国家自然科学基金(50872033);国家科技支撑计划项目(2007BAE55B03);973项目(2006CB600907)资助~~

摘　　要：热固型酚醛树脂、蜜胺、间甲酚和甲醛水溶液在碳酸钠催化下,经溶液-溶胶-凝胶过程合成了有机水凝胶,有机水凝胶经溶剂置换和超临界干燥形成了有机气凝胶。研究了裂解条件、固形物浓度、蜜胺/酚醛树脂比和间甲酚/酚醛树脂比对有机气凝胶纳米孔在裂解过程中稳定性的影响。结果表明:在相同的反应物配比下,随裂解温度的升高和时间的延长,气凝胶纳米骨架烧结程度增加,炭气凝胶的中孔分布向小孔方向移动。在酚醛树脂浓度为7.5g/100mL时,有机气凝胶的纳米骨架稳定性好,耐烧结性能好。在蜜胺/酚醛树脂比大或间甲酚/酚醛树脂比小时,有机气凝胶的纳米骨架的稳定性和耐烧结性好。这是由于构成有机气凝胶中孔的纳米骨架稳定性与其连续性及分子间作用力有关。Organic aerogels were synthesized by the solution-sol-gel polymerization of melamine （M）, phenolic resole （PR）, m-cresol （m-C） and formaldehyde in a basic aqueous solution followed by supercritical petroleum ether drying. The stability of the nanostructure of the organic aerogels in pyrolysis was investigated. It was found that bimodal mesopores are formed in organic aerogels and the sintering of a nanonetwork that forms the mesopores occurs during the pyrolysis of the aerogels, leading to a decrease of mesopore size and volume. The sizes and volumes of the large mesopores （5-50 nm） decrease with pyrolysis temperature and/or time for the same reactant formulation. In all cases the small mesopores （2-5 nm） are more stable during pyrolysis than the large mesopores. The large mesopores prepared at PR concentration of 7.5g/100mL are more stable during pyrolysi＇s than those at 10g/100 mL. The stability of the large mesopores during pyrolysis for organic aerogels increases with M/PR ratio or decreases with m-C/PR ratio, which can be ascribed to an increase of intermolecular interaction in the nanonetwork of the organic aerogels with increasing M/PR ratios or with decreasing m-C/PR ratios.

关 键 词：溶胶-凝胶 有机气凝胶 炭气凝胶 裂解 孔 

分 类 号：TQ320.1[化学工程—合成树脂塑料工业]