气体阻隔用聚氨酯材料研究进展

Recent research progress of polyurethane for gas barrier application

聚氨酯是一种具有优异的柔韧性、弹性、可控的硬度、较高的拉伸强度、耐磨性、耐化学品性、低温稳定性及热稳定性的聚合物,适合作为气体阻隔功能的主体材料,在燃油蒸汽隔离、食品包装、轮胎修补、热气球和防火隔离等方面都有广泛的应用。聚氨酯主要由柔性链段和刚性链段共聚而成,两种结构之间由于热动力学稳定性差异所引起的相分离会制约对气体的屏蔽能力,调整分子结构和引入纳米材料强化是提高聚氨酯气体阻隔性的有效手段。蒙脱土和石墨烯是研究较为深入的纳米增强相,通过片层堆叠和引入氢键等机理提高聚氨酯对水蒸气、O_(2)、CO_(2)等气体的阻隔能力。本文从气体扩散与阻隔机理、本征聚氨酯气阻材料、纳米增强聚氨酯气阻材料等几方面阐述了气体阻隔用聚氨酯材料近年来的研究进展,并基于目前的实验进展及理论认知,对材料未来的研究方向如优化本征聚氨酯材料分子结构、提高对纳米增强相分散程度的深入探索和关注小分子气体阻隔性能等方面进行了展望。

Polyurethane is a unique polymer with excellent flexibility,elasticity,controllable hardness,fine tensile strength,abrasion and medium resistant,and stable in both low and high temperature.Since it is suitable for use as a gas barrier material,so it has a wide range of applications in fuel gas isolation,food packing,tire repairing,hot balloon,and flame retardance.The copolymerization of soft segments and hard segments formulated polyurethane,and its gas barrier properties depends on phase separation caused by two thermodynamically incompatible segments.Adjustment of molecular structure and fabrication of nano composites are effective approaches to enhance gas barrier properties.Nanoclay and graphene are widely studied as nano fillers for polyurethane,they improve the barrier ability of polyurethane to water vapor,oxygen,and carbon dioxide and other gases by blocking mechanism of which is reported to be layer stack and hydrogen bonding.In this article,mechanism of gas transport and barrier,intrinsic polyurethane,polyurethane nanocomposites is discussed.Finally,the development direction of polyurethane for gas barrier application is prospected.