Blends of high-density polyethylene (HDPE) and a reactive ethylene terpolymer (RET) were developed as a protective coating material for steel. A morphological study with scanning electron microscopy (SEM) indicated that blends of HDPE and RET are immiscible, while high interaction between these two phases was found. Crystallization and thermomechanical behavior of the blends were investigated using differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA). The crystallinity of HDPE decreased with the incorporation of RET slightly due to the disturbance of the highly viscous RET melt during crystallization. Tensile tests indicated that the addition of RET reduced both strength and modulus but increased the strain-to-break. Adhesion to steel substrates was improved with the incorporation of the RET component. An optimum composition of RET loading was detected to be in the range of 25-33 wt %, leading to the best adhesive performance, high tensile strength, and strain-to-failure of the blend material. (c) 2007 Wiley Periodicals, Inc.