Study Of The Structure And Properties Of The Special Rubber / Ommt Nanocomposites

In this research, several special purpose rubber/OMMT nanocomposites have been prepared by direct mixing intercalation method. Organic montmorillonite were prepared in our lab. The structure of nanocomposite was studied by TEM and XRD. The effects of OMMT content on mechanical properties, oil resistance, thermal stability of rubber/OMMT nanocomposites were studied. The dynamic mechanical properties of nanocomposites were studied by DMTA.The results of TEM and XRD showed that the OMMT layers were intercalated into the FKM matrix, the OMMT layers were exfoliated in the HNBR matrix and the OMMT layers were half-exfoliated in the CSM matrix. The OMMT layers were dispersed well in the rubber matrix. According to statistical data, average thickness of layers was 10nm, and the thickness of the biggest layers was less than 40nm, only a few layers were exfoliated in monolayer whose thickness was about 1nm.The results of mechanical properties showed that the OMMT layers with high aspect ratio and fine dispersed structure endowed the nanocomposites with excellent mechanical properties. The hardness, tensile strength and elongation at break of rubber/OMMT nanocomposites were much higher than those of rubber filled with carbon black. The results showed that the mechanical properties of nanocomposites improved with the increased of OMMT content when the OMMT content is lower.The thermal stability, oil resistance and aging properties of special purpose rubber/OMMT nanocomposites were investigated. The nanocomposites had excellent thermal stability and swell property because of the excellent gas barrier property of OMMT layer. The tensile strength and stress at certain elongation increased after aging due to the improved uniformity and densification of cross-linking network.When the OMMT content is small, the abrasion properties of special purpose rubber/OMMT nanocomposites can be improved. When the OMMT content increased to a certain value, the re-aggregation of OMMT has a negative effect on the nanocomposites.The dynamic mechanical properties of nanocomposites were studied by DMTA. The results showed that the nanocomposites had excellent dynamic mechanical property and a good rolling resistance because the OMMT layers had much more restriction to the rubber chains.