Influence of EVA-g-MAH compatibilizer on adhesion strength, mechanical properties and thermal behavior of EVA/SBS hot melt adhesive blends

Hot melt adhesives (HMAs) were prepared by compounding ethylene vinyl acetate copolymers (EVA) and styrene-butadiene-styrene block copolymer (SBS). To enhance the compatibility of EVA and SBS, different proportions of EVA-g-MAH were added as compatibilizers. The thermal behavior, rheological properties and adhesion of the EVA/EVA-g-MAH/SBS ternary blends have been systematically investigated. The results revealed that the melt viscosity increased with the addition of EVA-g-MAH, whereas the mechanical strength initially increased with the addition of EVA-g-MAH up to a threshold value (6 wt%), followed by a gradual decrease. These results are consistent with the SEM observations. The adhesion strength of the EVA/EVA-g-MAH/SBS ternary samples was assessed by 180 degrees peeling test of cotton strip/adhesives/stainless steel stack. The results revealed that adhesion performance and compatibility of EVA/SBS composite HMAs were greatly improved due to the addition of EVA-g-MAH. In addition, the sample containing 6 wt% EVA-g-MAH exhibited excellent adhesion performance and optimal compatibility. The peeling strength reached a maximum value of 36 N mm(-1) with cohesive failure mode, which corresponds to a 33.3% increase as compared to the system without compatibilizer.