复合阻燃剂对琼脂/PVA气凝胶的性能影响  

Effect of Compound Flame Retardant on the Properties of Agar-based Aerogel

作　　者：强小虎 欧阳成伟 郭鑫 黄大建 QIANG Xiao-hu;OUYANG Cheng-wei;GUO Xin;HUANG Da-jian(School of Materials Science and Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]兰州交通大学材料科学与工程学院,兰州730070

出　　处：《兰州交通大学学报》2023年第3期124-131,共8页Journal of Lanzhou Jiaotong University

基　　金：甘肃省科技计划资助(20JR2RA002);甘肃省黄河水环境重点实验室(120011060614);临泽县凹凸棒石产业开放课题科技项目(LZKFKT-2103)。

摘　　要：氢氧化镁(MH)是一种在工业中应用广泛的无机阻燃剂,其存在阻燃效率低且与基体材料相容性差等缺点。为解决这一问题,以菱镁矿(MS)为原料,通过煅烧处理制备具有较高活性的氧化镁(MgO),通过水化法在琼脂(AG)/聚乙烯醇(PVA)溶胶基质中原位生成了MH,避免了MH的团聚。为解决单一MH阻燃效率低、填充量大的缺陷,引入了海藻酸钠(SA)、一维纳米粘土凹凸棒石(Pal)作为阻燃协效剂,借助冷冻干燥工艺制备了AG/PVA/SA/MH/Pal复合气凝胶,采用XRD、FT-IR、SEM等表征手段对复合气凝胶的性能进行了研究。结果表明:在SEM下观察到复合气凝胶呈现三维多孔网络状结构,MH呈花簇状且在聚合物多孔基体中分布良好,无明显聚集现象。相较于SA/MH体系,Pal的引入在一定程度上增强了复合气凝胶的力学强度,含20%的MH和20%的Pal的AG/PVA/SA体系气凝胶的压缩模量相较于含40%的MH气凝胶提升了45.26%;TGA测试结果表明Pal的引入能提高复合气凝胶热稳定性。SA/MH/Pal复合体系相较于SA/MH体系具有更理想的阻燃效果,主要表现在降低热释放速率、减少热释放总量以及促进炭层稳定性方面。Magnesium hydroxide(MH)is a kind of inorganic flame retardant which has been widely used in industry,but MH has some shortcomings such as low flame-retardant efficiency and poor compatibility with substrate materials.In order to solve this problem,magnesium oxide(MgO)with high activity was prepared by calcination using magnesite(MS)as raw material.MH was generated in the polyvinyl alcohol(PVA)sol matrix by hydration method,avoiding the agglomeration of MH.In order to solve the defects of low flame retarding efficiency and large filling capacity of single MH,sodium alginate(SA)and one-dimensional nano-clay attapulgite(Pal)were introduced as flame retarding co-effecting agents,and AG/PVA/SA/MH/Pal composite aerogel was prepared by freeze-drying process.The properties of composite aerogel were studied by XRD,FT-IR and SEM.The results show that the composite aerogel presents a three-dimensional porous network structure under SEM,MH presents a flower cluster and is well distributed in the porous polymer matrix,without obvious aggregation phenomenon.Compared with SA/MH system,Pal system enhanced the mechanical strength of composite aerogel to some extent.The compression modulus of AG/PVA/SA system containing 20%MH and 20%Pal system increased by 45.26%compared with 40%MH aerogel.TGA test results show that Pal can improve the thermal stability of composite aerogel.Compared with SA/MH system,SA/MH composite system has better flame retarding effect,mainly in reducing the heat release rate,reducing the total heat release and promoting the stability of carbon layer.

关 键 词：复合气凝胶 氢氧化镁 阻燃 原位生成 

分 类 号：TB332[一般工业技术—材料科学与工程]