有机蒙脱土/聚氨酯弹性体复合材料的微观形貌及力学性能

以十八烷基三甲基氯化铵（OTAC）为改性剂，通过离子交换法改性钠基蒙脱土（MMT）制得有机蒙脱土（OMMT）；以聚丙二醇（PPG）和4，4'-二苯基甲烷二异氰酸酯（MDI）为单体，1，4-丁二醇（BDO）为扩链剂，合成聚氨酯弹性体（PUE）基体；并采用预聚体法制备了OMMT/PUE复合材料。FTIR和XRD测试结果表明:OMMT在2 921 cm-1和1 469 cm-1处出现-CH₂吸收峰，表明OTAC分子链成功插入到OMMT片层，由OMMT的耐热性推算OTAC的插层量为24%，且OMMT的层间距较MMT增加了0.7 nm。OMMT/PUE复合材料的SEM和XRD结果显示:适量的OMMT在PUE基体中均匀分散，且以完全剥离的形式存在，其主要原因是:一方面由于OTAC分子与PUE软链间存在较强的作用，另一方面OMMT表面活性基团与基体间也存在一定的界面作用，两种作用均有利于提高OMMT/PUE复合材料的力学性能。力学性能测试结果表明:当OMMT的含量为3wt%时，OMMT/PUE复合材料的拉伸强度、扯断伸长率及断裂拉伸强度比PUE分别提高了37%、28%和34%，力学性能得到明显改善。 

Micro-morphology and mechanical properties of organic montmorillonite/polyurethane elastomer composite

Sodium montmorillonite (MMT) was modified by octadecyl trimethyl ammonium chloride (OTAC) via cation exchange and organic montmorillonite (OMMT) was got. Polyurethane elastomer (PUE) was synthesized taking 4,4'-diphenylmethane diisocyanate (MDI) and polypropylene glycol (PPG) as the raw materials and 1,4-butanediol (BDO) as chain extender, and then OMMT/PUE composite was prepared by the prepolymer method. The results of FTIR and XRD show that the characteristic peaks of -CH₂(2 921 cm^-1 and 1 469 cm^-1) appear and indicate that the new groups have been introduced into the layers of OMMT, the intercalation quantity of OTAC is about 24% by the heat resistance of MMT and OMMT, and the interlayer spacing of OMMT is 0.7 nm larger than that of MMT. The analytical results of SEM and XRD of OMMT/PUE composites reveal that proper OMMT disperses evenly in the PUE matrix, and OMMT is peeled completely. This phenomenon can be explained by two main reasons, i.e. one is the strong interaction between OTAC molecular and soft segments of PUE, and the other is the interface interaction amid the active groups of OMMT and PUE matrix. The test results of mechanical properties of OMMT/PUE composites display that the maximum tensile strength, elongation at break and breaking tensile strength of OMMT/PUE composite are 37%, 28% and 34% higher than that of PUE matrix, respectively, when the content of OMMT is 3wt%, and the mechanical properties of OMMT/PUE composites are significantly improved.