硅烷功能化蒙脱土/苯乙烯-乙烯-丁二烯-苯乙烯嵌段共聚物纳米复合材料的制备及性能

Preparation and properties of silane functionalized montmorillonite/styrene-ethylene-butadiene-styrene block copolymer nanocomposites

用十六烷基三丁基溴化磷、甲基三甲氧基硅烷连续对钠基蒙脱土(Na+-MMT)进行改性,制得了有机插层蒙脱土(H-OMMT)和硅烷功能化蒙脱土(S-H-OMMT),并采用熔融共混法制备了功能化蒙脱土/苯乙烯-乙烯-丁二烯-苯乙烯嵌段共聚物(SEBS)纳米复合材料,表征了S-H-OMMT微观结构,研究了S-H-OMMT在SEBS基质中的分散性及复合材料的热稳定性、拉伸性能。结果表明,十六烷基三丁基溴化磷和甲基三甲氧基硅烷对Na^+-MMT实现了有机化改性,H-OMMT和S-H-OMMT的层间距相比Na^+-MMT增大,H-OMMT呈明显的片层状,而S-H-OMMT的片层更为松散;H-OMMT和S-H-OMMT均与SEBS形成插层结构,后者甚至产生部分剥离结构,相容性明显改善;少量S-H-OMMT(质量分数小于3%)的加入可改善SEBS的热稳定性和拉伸性能。

Na＋-montmorillonite（ Na＋-MMT） was treated continuously by hexadecyltri-n-butyl phosphonium bromide and methyltrimethoxysilane to obtain intercalated MMT（ H-OMMT） and silane functionalized MMT（ S-H-MMT）,and the functionalized MMT / styrene-ethylene-butadiene-styrene block copolymer（ SEBS） nanocomposites were prepared via melt blending process. The microstructure of S-H-OMMT was characterized,the dispersion of S-H-OMMT in SEBS matrix,and the thermal stability and tensile properties of nanocomposite were studied. The results showed that MMT was modified well,the layer spacing of H-OMMT and S-H-OMMT were larger than that of Na＋-MMT,H-OMMT exhibited obvious lamellar structure,but S-H-OMMT incompact. H-OMMT and S-H-OMMT dispersed in SEBS matrix all in the form of intercalation,and the latter dispersed even in the partially exfoliated structure,resulting in improved compatibility. Only by a small amount of S-H-OMMT（ mass fraction less than3%） could thermal stability and tensile properties of the SEBS nanocomposites be improved.