Dependence of Adhesion Properties on Blend Ratio of Ethylene-Propylene-Diene RubberStandard Malaysian Rubber Blend Adhesive

Abstract EN

Viscosity, tack and, peel and shear strengths of ethylene-propylene-diene rubber (EPDM)/standard Malaysian rubber (SMR L) blend adhesive were studied using various blend ratios of the two rubbers, ranging from 0 to 100% EPDM.

Coumarone-indene resin, toluene, and poly(ethylene terephthalate) (PET) were used as the tackifier, solvent, and coating substrate, respectively.

The tackifier content was fixed at 40 parts per hundred parts of rubber (phr).

A SHEEN hand coater was used to coat the adhesive on PET film at four coating thicknesses, that is, 30, 60, 90, and 120 µm.

The viscosity and adhesion properties were determined by a Brookfield viscometer and a Lloyd Adhesion Tester, respectively.

Results show that the viscosity, loop tacks and peel strength of blend adhesives decrease gradually with increasing % EPDM.

This observation is attributed to dilution effect and lowering in wettability and compatibility.

Shear strength, however, passes through a maximum at 20–40% EPDM blend ratio, an observation which is ascribed to culmination of cohesive strength at the optimum EPDM blend ratio.

Increasing coating thickness increases the adhesion properties in all blend ratios in this study.