Viscosity, peel strength, shear strength and tack of styrene-butadiene rubber (SBR)-based pressuresensitive
adhesive were studied using silica as the filler. The silica content was varied from 10-50 parts
per hundred parts of rubber (phr). The tackifying resin, solvent and coating substrate used were gum rosin,
toluene and poly(ethylene terephthalate) (PET) respectively. Viscosity of the adhesive was determined by
a Brookfield Viscometer. Both peel strength, shear strength and tack were measured by a Lloyd Adhesion
Tester operating at 10-60 cm/min. Results show that viscosity increases with silica loading due to the
concentration effect. Peel strength, shear strength and tack passes through a maximum value at 20 phr
silica loading, an observation which is attributed to the culmination of wettability at the optimum silica
content. Peel strength decreases with the angle of testing at a fixed silica loading and coating thickness.
Both peel strength, shear strength and tack increases with coating thickness and testing rates.