阻燃OMMT/WPU纳米复合材料的制备及性能研究

采用端羟基聚丁二烯（HTPB）剥离层状有机蒙脱土（OMMT）为纳米片层，并与异佛尔酮二异氰酸酯（IPDI）、二羟甲基丙酸（DMPA）等单体通过原位聚合法制备了OMMT纳米片改性的水性聚氨酯（OWPU）纳米乳液及胶膜。利用小角XRD、TEM、DLS、EDS、TGA、LOI、CONE以及SEM对样品的结构和性能进行了表征。结果表明，HTPB剥离的OMMT纳米片的衬度均匀，完整性较好；改性后OWPU的乳液粒径增大，胶膜的弹性模量、热稳定性、抗熔滴性和阻燃性能均得到明显地改善，其中弹性模量可提高59.4%，热释放速率峰值可降低36.9%；燃烧炭渣表面形貌显示，瓦片状蒙脱土相互穿插形成了具有团簇结构的蒙脱土覆盖层。

Preparation and properties of flame-retardant OMMT/WPU nanocomposites

The layered organic montmorillonite (OMMT) was first exfoliated into nanosheets by hydroxyl-terminated polybutadiene (HTPB). The OMMT nanosheets with HTPB were then assembled into environment-friendly waterborne polyurethane (OWPU) emulsion and film by in situ polymerization with monomers such as isophorone diisocyanate (IPDI) and dimethylolpropionic acid (DMPA) and so on. Small-angle XRD and TEM examinations indicated that the OMMT nanosheets had uniform contrast and good integrity. DLS, EDS, TGA, LOI, and CONE examinations suggested that the emulsion particle size, elastic modulus, thermal stability, droplet resistance and flame retardant properties of OWPU had been significantly improved. Particularly, the elastic modulus of OWPU nanofilm was increased by a maximum of 59.4% and a peak heat release rate of OWPU nanofilm was decreased by a maximum of 36.9 %. In addition, the surface morphology of the burning char residue showed that the tile-shaped OMMT interpenetrates to form a covering layer with a cluster structure.