Effect of Molecular Weight of Rubber on Tack and Peel Strength of SMR L-Based Pressure-Sensitive Adhesives using Gum Rosin and Petroresin as Tackifiers

摘要

Loop tack and peel strength of natural rubber (SMR L)-based pressure-sensitive adhesive were studied using five different molecular weights of SMR L. Gum rosin and petroresin were used as tackifiers, whereas toluene was chosen as the solvent throughout the experiment. A SHEEN hand coater was used to coat the adhesive on a polyethylene terephthalate (PET) substrate at a coating thickness of 30, 60, 90 and 120 m. Loop tack and peel strength were determined by a Llyod Adhesion Tester operating at 30 cm/min. Results show that maximum values of loop tack and peel strength were obtained at a molecular weight of 8.5 104, an observation which is attributed to maximum wettability of adhesive on the substrate. Loop tack and peel strength increases with coating thickness for all molecular weight of rubber and tackifiers studied.