Statistical analysis on the effect of the molecular weight and testing rate on peel strength of epoxidized natural rubber (ENR 25)-based adhesives

Epoxidized natural rubber (ENR)-based adhesive was prepared using gum rosin and toluene as the tackifier and solvent, respectively. Peel strength of adhesive was determined using a Llyod adhesion tester operating at different rates of testing. Result shows that peel strength increases up to an optimum molecular weight of 6.5 × 104 of ENR 25. This observation is attributed to the combined effects of wettability and mechanical strength of rubber. Differential scanning calorimetry measurement confirms the miscibility of tackifier and ENR 25. Statistical analysis was used to further investigate the effect of molecular weight and testing rate on the peel adhesion of the adhesive.