Effect of molecular weight and testing rate on peel and shear strength of epoxidized natural rubber (ENR 50)‐based adhesives

Abstract

The dependence of peel strength and shear strength of epoxidized natural rubber (ENR-50)-based pressure sensitive adhesive on molecular weight and rate of testing was investigated using coumarone-indene as the tackifying resin. Toluene and polyethylene terephthalate were used as the solvent and substrate respectively, throughout the study. A SHEEN hand coater was used to coat the adhesive on the substrate at a coating thickness of 120 lm. All the adhesion properties were determined by a Llyod Adhesion Tester operating at different rates of testing. Result shows that peel strength and shear strength increases up to an optimum molecular weight of 4.2 Â 10 4 of ENR 50. For peel strength, the observation is attributed to the combined effects of wettability and mechanical strength of rubber at the optimum molecular weight, whereas for the shear strength, it is ascribed to the optimum cohesive and adhesive strength which enhances the shear resistance of the adhesive. Peel strength and shear strength also increases with increase in rate of testing, an observation which is associated to the viscoeslastic response of the adhesive. DSC and FTIR study confirms the miscibility of tackifier and the ENR 50.

Development of hydrolysed protein-based plywood adhesive from slaughterhouse waste: effect of chemical modification of hydrolysed protein on moisture resistance of formulated adhesives

“…Studies on adhesive strength of polymers have revealed that there is an optimum molecular weight of polymers at which the optimum combination of adhesive and cohesive forces is achieved that contributes to the highest shear strength. 37,[39][40][41] Since the curing condition remains same for all the formulations, the decrease in performance of the formulation reacted for 180 minutes is most likely due to the properties of uncured adhesive such as viscosity, ow property, and penetration ability.…”

Active Bio-Based Pressure-Sensitive Adhesive Based Natural Rubber for Food Antimicrobial Applications: Effect of Processing Parameters on Its Adhesion Properties

“…In order to develop the NR-based PSA, the reduction in molecular weight NR was the main factor that affected the adhesion properties of the PSA [ 18 , 19 , 20 , 21 ]. Therefore, the effect of nip gaps has been first investigated by varying in the range 1–4 mm.…”

“…An increase of mastication time led to an increase in the T-peel of NR-PSA/CO for kraft paper, nylon, and Al foil ( Table 3 ). The results suggested that the considerable reduction in the molecular weight of NR during mastication enhanced the adhesion properties of PSA [ 16 , 18 , 19 , 20 ]. Figure 5 shows that there was no residue of NR-PSA/CO appears on all the coating substrates after peeling.…”

“…However, their production cost is found to be still high and the obtained PSAs are non-biodegradable. Therefore, in order to replace synthetic rubber, the PSA based-natural rubber (NR) has been developed because of its non-toxic nature and good tacking with many types of substrate materials especially when its molecular weight is being reduced [ 16 , 17 , 18 , 19 , 20 ]. Moreover, it can be used as a bio-device for a controlled release system [ 21 ].…”

Utilization of Slaughterhouse Waste in Value-Added Applications: Recent Advances in the Development of Wood Adhesives

“…Studies on the adhesive strength of polymers have demonstrated that a balance of cohesive and adhesive strengths results in stronger adhesion, and the most favorable combination of adhesive and cohesive forces is achieved at an optimum molecular weight of the polymers. Further, the interplay between the molecular weight of polymers and their adhesive strength is governed by the extent of physicochemical interactions and/or crosslinking of polymer chains [ 57 , 100 , 101 , 102 , 103 ]. Additionally, chemical crosslinking generates rigid three-dimensional networks of polymers, and enhances the water resistance property.…”