Characterization of organoclay-networks modified low-temperature hydrogenated nitrile butadiene rubber composites

Abstract

The low-temperature grade hydrogenated nitrile butadiene rubber (LTG-HNBR) composites with organoclays were successfully prepared for the purpose of using the clay-networks to improve bulk properties. In order to construct different clay-networks, three montmorillonite (MMT) modified by surfactants were added and then their dispersions and affinities in the rubber were compared. Transmission electron microscope and small-angle X-ray scattering results showed that 10 phr organoclays form partially exfoliated and intercalated structures in the matrix despite of modifier types. FTIR and particle analysis data display that increasing the number of alkyl tails of modifier molecules decreases the affinities of clays and their extent of intercalation in rubber whereas the special modifier with coupling agent enhances their compatibility with the bulk. The mechanical, oil resistance, and thermal properties of the composites are greatly reinforced by clay-networks which parallel their interactions. Importantly, the addition of clays barely changes glassy temperature (Tg) of rubber bulk, but it improves its low-temperature elasticity. Therefore, it is stressed that organoclay hybrid networks are very useful to modify low-temperature rubber. We believe that LTG-HNBR composites with organoclays may serve some applications of oil-sealing products. POLYM. COMPOS., 35:1306–1317, 2014. © 2013 Society of Plastics Engineers