Synthesis, Characterization and Properties Evaluation of Polybutadiene Rubber Based Nanocomposites: Ex situ and In situ Approaches

Abstract

In the present study, elastomer nanocomposites based on polybutadiene rubber and dierent kind of nanollers were prepared either by using in situ or ex situ methods. The eects of dierent nanoller and their compounding on the physico-mechanical and thermal properties of BR nanocomposites were investigated. Nanollers like nanosilica, sepiolite, pangel, hydrotalcite, montmorillonite, and CNT were used as reinforcing agent. The textural properties of the nanomaterials were characterized by powder X-ray diraction ( XRD), and BET-surface area measurements. The mechanical properties of various nanocomposites prepared by ex situ method were compared with composites made of conventional llers such as carbon black and silica. The result indicates that composites prepared from nanollers show higher mechanical properties as compared to conventionally lled composites. It is also observed that the performance of nanosilica in BR matrix enhanced in presence of silane as a coupling agent. The composite containing 3 phr loaded Cloisite 20A showed 245% improvement in tensile strength compared to the matrix devoid of nanomaterial. Also the composite containing 5 phr loaded CNT showed 137% improvement in tensile strength. Thermal analysis of the nanocomposites and gum BR vulcanizates itself was done by thermogravimetric analyzer. It showed that the addition of nanoller increses the thermal stability of the nanocomposites. This may be due to the heat shielding eect of the incorporated nanollers in the polymer matrix. The eect of best nanollers, obtained from ex situ method such as CNT and nanosilicasilane at minimum ller concentration, on the mechanical properties of BR nanocomposites is further studied via in situ process. A maximum of 72 % improvement in tensile strength is accomplished using 1 phr nanosilica loaded BR nanocomposites as compared to gum BR vulcanizate. The swelling and thermo gravimetric analysis results of all the BR based nanocomposites are in good agreement with mechanical properties of the same.