氢化丁腈橡胶/聚甲基丙烯酸镁/有机蒙脱土纳米复合材料制备及其耐介质老化性能

采用原位聚合和混炼插层相结合技术制备了氢化丁腈橡胶/聚甲基丙烯酸镁/有机蒙脱土(HNBR/PMgMA/OMT)纳米复合材料,通过XRD,SEM和TEM等测试方法研究了HNBR/PMgMA/OMT纳米复合材料的结构、形态和性能.PMgMA离子簇与未反应完全的MgMA单体形成纳米-微米共存形态结构,PMgMA对HNBR有显著的增强效果,HNBR/PMgMA/OMT纳米复合材料具有良好的加工性能、物理机械性能和耐介质老化性能.TEM结果显示MgMA/OMT并用有助于OMT剥离分散,有机蒙脱土在硫化胶中形成以剥离和插层为主、反插层和未插层共存的微观结构;SEM显示当MgMA/OMT用量为20/10份时能明显改善复合材料的界面结合,此时纳米复合材料的拉伸强度、扯断伸长率和扯断永久变形分别为30.2 MPa,520%和30%;同时具有优异的耐热空气和耐油老化性能,耐热水性能也明显改善,在165℃的热空气、水和油中长期老化14天的老化系数分别达到0.61,0.63和0.84,其耐介质老化性能明显好于炭黑增强HNBR硫化胶及HNBR/PMgMA复合材料.良好的蒙脱土片层分散结构是提高HNBR/PMgMA/OMT纳米复合材料耐介质老化性能的主要原因.

PREPARATION OF HNBR/PMgMA/OMT NANOCOMPOSITES AND THEIR AGING RESISTANCE IN DIFFERENT MEDIA

Nanocomposites composed of hydrogenated nitrile rubber/magnesium methacrylate/organic montmorillonite(HNBR/PMgMA/OMT) were prepared by in situ polymerization and mixing intercalation.The structure,morphology and properties of the nanocompostie were investigated by XRD,SEM,TEM,etc.The nano-micro coexistence structure was formed by PMgMA ion clusters and MgMA monomer.MgMA significantly enhanced the properties of HNBR composites.HNBR/PMgMA/OMT nanocomposites have favorable processing,mechanical properties and resistant aging properties in different media.TEM images revealed that MgMA can help OMT in exfoliating and dispersing,while the composition of MgMA/OMT facilitated the peeling and dispersion of OMT.OMT in the vulcanizates formed a microstructure mainly caused by exfoliation and intercalation,and also by the coexistence of de-intercalation and un-intercalation.SEM results indicated that the interface bonding can be significantly improved with a mixing ratio of MgMA/OMT as 20/10,therefore,the tensile strength,elongation at break and permanent deformation reached 30.2 MPa,520% and 30%,respectively;meanwhile,the hot air,oil and water resistant properties were also improved apparently.An aging coefficient of 0.61,0.63 and 0.84 was attained after aging at 165℃ in air,water and oil,respectively,for 14 days.And the resistant aging property of medium is higher than that of the HNBR composite reinforced by carbon black and MgMA,respectively.The improvement of aging resistance in different media is mainly due to the better dispersed layer structure of organic montmorillonite.