An analysis of the combined effects of isocyanate HMDI and maleic anhydride (MAPE) coupling agents on the mechanical properties of HDPE- wood flour composite

Coupling agents in wood fiber reinforced plastic composites play an important role inimproving compatibility and adhesion between polar wood fiber and non-polar polymermatrices by forming bridges of chemical bonds between the fiber and the matrix. Maleatedpolyethylene (MAPE) and diisocyanate (HMDI) are two most common coupling agents whichare subject to evaluation, singly and in mixture. Polypropylene and wood fibers werecompounded with Maleated polyethylene (MAPE) and diisocyanate (HMDI) in concentration of2% and 4% in solitary form and mixture form (HMDI %2 + MAPE %2) into pellets using acounter-rotating twin-screw extruder and mechanical test specimens were prepared by injectionmolding. The result showed that adding 4% MAPE and 2% HMDI individually lead to increasein flexural and tensile strength of the composites. Also adding (%2HMDI + %2MAPE) causedan increase of flexural, tensile and in particular the impact strength