USING THE BOND-ENERGY DENSITY TO PREDICT THE REINFORCING ABILITY OF A COMPOSITE

A model is proposed to predict the ability of a filler to reinforce a polymer. The model combines the effects of filler particle size, filler surface chemistry and filler volume fraction into one parameter called the bond energy density. Bond energy density is defined as the total interfacial bond energy per unit volume of a polymer composite. Bond energy density is determined by Fowkes's equation. The critical bond energy density, which is equivalent to the bond energy density of the composite when its tensile strength equals that of its matrix, determines whether a filler will reinforce or weaken a polymer. To get a filler reinforcing effect, the bond energy density of the composite must be greater than its critical bond energy density.