Tack and Shear Strength of Adhesives Prepared from Styrene-Butadiene Rubber (SBR) Using Gum Rosin and Petro Resin as Tackifiers

Tack and shear strength of styrene-butadiene rubber (SBR)-based pressure-sensitive adhesive were studied using gum rosin and petro resin as the tackifiers. The concentration of the tackifying resin was varied from 0 to 100 parts per hundred parts of rubber (phr). Toluene was used as the solvent throughout the experiment. The rolling ball technique was used to measure the tack of the adhesive, whereas, shear strength was determined by a TA-HDi Texture Analyser. Results show that the tack of the adhesive increases with increasing tackifier loadings for both tackifier systems. However, shear strength indicates the reverse behavior with increasing resin content, an observation which is attributed to the decrease in cohesive strength as the tackifier concentration is increased. Both tack and shear strength of the adhesives increases with molecular weight of SBR. Adhesive containing petro resin consistently exhibits higher values than the gum rosin system due to better wettability and compatibility in the former system.