低温耐油蒙脱土/ 氢化丁腈的制备和性能研究

采用热机械共混的方法,制备了有机蒙脱土(OMMT)/低温氢化丁腈(HNBR)的橡胶材料.热混炼工艺增强了OMMT在氢化丁腈中的分散性能,从而获得了性能优异的HNBR橡胶.SAXS、SEM和TEM照片展示了OMMT主要以插层结构和少量聚集体存在HNBR橡胶中.DSC曲线和压缩耐寒系数测试表明,少量添加OMMT,可在不明显限制HNBR橡胶分子链的运动条件下,提高HNBR填料网络密度,增加橡胶内部的网络协同密度,从而增强HNBR橡胶的低温弹性.少量OMMT( ＜10 phr)可大幅度提高HNBR橡胶的力学性能,但随着OMMT添加量继续增加,橡胶力学性能提高不明显.DMA测试表明,添加OMMT可提高其和HNBR橡胶的结合力及分散效果,成为增强HNBR橡胶力学性能的主要原因；与纯HNBR相比可提高橡胶的耐油性能.因此OMMT/HNBR复合材料是一种具有低温液压密封应用前景的橡胶材料.

Preparation and Properties of Low-Temperature andOil-Resistance OMMT/ HNBR Rubber

Using the methods of thermal twin roller mixing, the OMMT/ HNBR rubber were prepared. The dispersion
of OMMT in HNBR was enhanced by the preparations, thus good properties of HNBR were obtained. The results
of SAXS, SEM and TEM showed that the OMMT layers were intercalated in the HNBR matrix and formed a few
aggregations. DSC plots and cold-resistance coefficient results displayed that the addition of OMMT is not restricted
the chain segment motions of HNBR, but increased the density of filler networks which thus improved their low-temperature
elasticity. By the addition of OMMT into HNBR, the mechanical properties of nanocomposites increased.
However, when the content of OMMT was beyond 10 phr, the amount of their aggregations increased and thus the mechanical
properties slowly improved. DMA measurements showed that there are strong interfaces between HNBR and
OMMT which lead to high mechanical properties of HNBR. In contrast with pure HNBR, the incorporation of OMMT
is helpful to improve the oil-resistance of HNBR. Therefore, we believe that OMMT/ HNBR rubber is a high-performance
oil-sealing material at the low temperature.