Investigation into elastomer nanocomposites based on SBR/epoxy–polyester hybrid/organoclay

Abstract

Elastomer nanocomposites based on styrene butadiene rubber (SBR), epoxy–polyester hybrid (EPH) and cloisite 15A were prepared via melt compounding at 105°C on a laboratory scale internal mixer regarding EPH degradation onset temperature of about 200°C. Different contents of EPH [i.e. 10, 20, 30 and 40 parts per hundred rubber (phr)] and nanoclay (1, 3, 5 and 7 phr) were introduced into the SBR matrix to investigate the effect of composition on the SBR compounds. Optimum cure time and scorch time of SBR/EPH, SBR/nanoclay and SBR/EPH/nanoclay compounds were observed to be shortened with increasing EPH and nanoclay content. Gel content values confirmed the increase observed in cross-link density of samples containing EPH and organoclay. X-ray diffraction results confirmed the intercalation of SBR macromolecular chains within the clay galleries. Mechanical properties, rheological characteristics and scanning electron microscopy (SEM) also confirmed the dispersion of clay and EPH within the SBR matrix. In fact, epoxy–polyester resin facilitates the state of dispersion of clay due to the interactions established between organoclay and EPH evidenced by FTIR spectra and SEM images. According to the mechanical tests carried out, incorporation of EPH and nanoclay into SBR also offers promising improvements in modulus, tensile strength and fatigue life as well as cure characteristics. A synergetic effect was observed in all investigated phenomena for nanocomposite samples containing both EPH and organoclay (SBR/EPH/clay).

Keywords:

• Styrene butadiene rubber
• Epoxy–polyester hybrid
• Organoclay
• Nanocomposite