Polymer/composite sheets were developed using sand as the filler, and high-density polyethylene (HDPE), by melting extrusion in a melt blender followed by compression molding. The effects of addition of filler, and the addition of polyethylene grafted maleic anhydride (PE-g-MA) as the compatibilizing agent were investigated by observing the morphology, the mechanical performance as well as the wettability characteristic via contact angle measurements. A decreasing trend was observed with filler addition, both for the Young’s modulus and yield stress values of each of the samples, from 1200.81 MPa and 35.15 MPa at 0 wt% to 1182.33 MPa and 23.11 MPa for the non-compatibilized sheet at 35 wt%, to 629.95 MPa and 9.56 MPa in the case of the compatibilized sheet respectively. However, addition of filler did not significantly affect the surface wetting in any case, thereby promoting good anti-wetting performance for both sets of sheets. As a result, the potential use of such synthetic composite sheets could be considered as a good alternative for applications which require reduced ductility or increased anti-wetting performance.