Study On Preparation And Mechanical Properties Of Clay/NBR Nanocomposite

The composite in which at least one dimension size of dispersed phases less than 100nm is defined as nanocomposite (NC). Using effective nano-compounding technique, clay layers can be separated and dispersed as monolayers or collection of layers thinner than 100nm in polymer matrix.A nano-compounding technique called "Clay layers/rubber latex intercalating technique" was put forward by our research group. Clay/NBR (including GNBR and CNBR) nanocomposite was prepared using this technique. A qualitative clay/NBR compounding model was established according to the study on preparation procedure and characters of latex and clay layers. The effects of clay types and its suspension, rubber latex, mixing, flocculation, recipe and cure time on morphology and properties were discussed.When using TEM and XRD to observe and characterize the microstructure of the prepared nanocomposite, it was shown that clay layers were dispersed as nano-level in the NBR matrix.The mechanical properties of Clay/NBR NC and NBR filled with N330 were compared using the volume fraction of filler as a standard. The results showed that the clay layers with ultra high aspect ratio and fine dispersed structure endowed the NC with excellent mechanical properties. The hardness, stress at 100% elongation, tensile strength and elongation at break of clay/NBR NCwere much higher than those of the NBR filled with CB (N330). However the permanent set of the clay/NBR NC was higher than that of CB/NBR system.The gas-permeability, swell property and aging property of the nanocomposite were investigated. The gas barrier property of NC with more than 20 phr clay filling amount was found to exceed that of CllR. The induction of clay into rubber also improved the swell property of NBR. The tensile strength and stress at certain elongation were found to increase after aging due to the improved uniformity and densification of cross-linking network.