Adhesive bond strengths have been determined for lap-shear joints of PS/LLDPE, and PS/CPE, a chlorinated version of polyethylene. Joints were formed at temperatures in the range of 180-280degreesC. In PS/LLDPE, bond strength at lower joining temperatures is compromised by the inability of LLDPE to act as electron acceptor to the donor properties of PS. However, at Tgreater than or equal to260degreesC, PS becomes a fluid capable of interacting through. dispersion forces only, leading to enhanced diffusion across the PS/LLDPE interface and much stronger adhesive bonds. An. acid-base pairing is in effect in joints of PS/CPE, resulting in strong joints made at Tless than or equal to240degreesC. The probable loss of acid-base interaction between the polymers at higher T, coupled with a failure of diffusion across the interface, leads to a lowering of the joint bond strength. Control over interfacial interactions is demonstrated to be a vital factor in the development of adhesive bonds.