| Composites using a recycled polyethylene matrix and wood fiber filler offer a low-cost, alternative use for recycled plastics. Using additives in the composite to promote interfacial bonding or dispersion of these two incompatible materials has been shown to offer some improvement of mechanical properties. This project studied the effects of combining two additives. The additives studied were stearic acid, a dispersing agent; maleic anhydride modified polypropylene; and ionomer modified polyethylene, both used to improve interfacial bonding. Testing included impact strength, tensile properties, and creep. In all areas except impact strength, the use of additives improved properties. The MAPP/stearic acid additive system exhibited the best overall creep and tensile properties, but decreased impact strength. The stearic acid/ionomer combination was the only one that did not reduce impact strength. None of the dual additive systems offered significant improvement over using single additives. |
