Zhu Zhaoqi, Niu Ye, Wang Shuo, Su Min, Long Yong, Sun Hanxue, Liang Weidong, Li An
College of Petrochemical Technology, Lanzhou University of Technology, Langongping Road 287, Lanzhou 730050, PR China.
College of Petrochemical Technology, Lanzhou University of Technology, Langongping Road 287, Lanzhou 730050, PR China.
J Colloid Interface Sci. 2022 Apr 15;612:35-42. doi: 10.1016/j.jcis.2021.12.138. Epub 2021 Dec 23.
The development of an environmental-friendly thermal insulation and flame retardant material has attracted widespread attention in modern architecture. In this work, a kind of novel aerogel composites were prepared by incorporation of Mg(OH) coated hollow glass microspheres (HGM) into chitosan (CSA) matrix and then cross-linking by glutaraldehyde (abbreviated as CSA-HGM-Mg(OH)). The as-prepared composite aerogel exhibits vertical directional channel with high porosity and excellent thermal insulation with a low thermal conductivity of 0.035 W m k. Besides, it shows excellent flame retardancy with a high limit oxygen index (LOI) value up to 50.8, which is one of the highest values among the most of flame retardants reported previously. Also, a very low peak heat release rate (pHRR) of 24.12 kW m was obtained which makes the aerogel composite reaching UL-94 V-0 rating. Such results may be attributed to a synergy effect by combination of its abundantly porous structure derived from HGM to give a better thermal insulation and excellent nonflammability of CSA and Mg(OH) to offer a superior flame retardancy. Taking advantages of its high mechanical strength, low cost materials, simple and scalable preparation method, CSA-HGM-Mg(OH) aerogel composites may hold great potential for future thermal insulation and flame retardant applications.
一种环保型保温阻燃材料的开发在现代建筑中引起了广泛关注。在这项工作中，通过将Mg(OH)包覆的空心玻璃微球（HGM）掺入壳聚糖（CSA）基质中，然后用戊二醛交联，制备了一种新型气凝胶复合材料（简称为CSA-HGM-Mg(OH)）。所制备的复合气凝胶呈现出具有高孔隙率的垂直定向通道，并且具有优异的保温性能，热导率低至0.035 W m⁻¹ K⁻¹。此外，它还表现出优异的阻燃性，极限氧指数（LOI）高达50.8，这是此前报道的大多数阻燃剂中最高的值之一。同时，获得了非常低的峰值热释放速率（pHRR），为24.12 kW m⁻²，这使得气凝胶复合材料达到了UL-94 V-0等级。这些结果可能归因于一种协同效应，即由HGM产生的大量多孔结构提供了更好的保温性能，以及CSA和Mg(OH)优异的不燃性提供了卓越的阻燃性。利用其高机械强度、低成本材料、简单且可扩展的制备方法，CSA-HGM-Mg(OH)气凝胶复合材料在未来的保温和阻燃应用中可能具有巨大潜力。
