凹凸棒石改性聚乙烯醇气凝胶性能研究

Properties of Attapulgite Modified Polyvinyl Alcohol Aerogel

气凝胶是一种具备优异隔热性能的新型材料。本研究以水溶性高分子聚乙烯醇(PVA)作基体材料,富含磷元素的植酸(PA)作交联剂,引入无机粘土凹凸棒石(APT)作增强材料。利用溶胶凝胶法,通过冷冻干燥制备了一系列不同APT质量分数的PVA/PA/APT复合气凝胶。利用扫描电镜(SEM)、傅里叶红外光谱(FTIR)、X射线衍射仪(XRD)表征了复合气凝胶的微观形貌和成分组成;利用万能拉力机测试了复合气凝胶力学性;利用热重测试、锥形量热测试等测试了复合气凝胶的热稳定性及阻燃性能。研究结果表明:APT被成功引入聚合物气凝胶中,与PVA/PA结合良好;APT的加入使得复合气凝胶材料力学性能显著提升。APT添加量达到50%时,压缩模量相较于纯聚合物样品提升了81%。热重测试、锥形量热测试结果表明APT有效地提升了复合气凝胶的热稳定性能;降低了热释放速率及烟雾产生速率。

Aerogel is a new kind of material with excellent thermal insulation properties. In this paper, PVA was used as the matrix material, phosphorus-rich PA as the cross-linking agent and inorganic clay APT was introduced as the reinforcing material. A series of PVA/PA/APT composite aerogels with different APT mass fractions were prepared by freeze-drying using the sol-gel method. The microscopic morphology and composition of the composite aerogels were characterized by scanning electron microscopy, Fourier infrared spectroscopy and X-ray diffraction;the mechanical properties of the composite aerogels were tested by a universal tensile machine;the thermal sta-bility and flame retardant properties of the composite aerogels were tested by thermogravimetric and cone calorimetric tests. The results showed that APT was successfully introduced into the pol-ymer aerogel and bonded well with PVA/PA;the mechanical properties of the composite aerogel were significantly improved with the addition of APT at 50%, and the compressive modulus was in-creased by 81% compared with that of the pure polymer sample. The thermogravimetric and cone calorimetric tests showed that APT effectively improved the thermal stability of the composite aer-ogel and reduced the heat release rate and smoke generation rate.