Abstract:The effects of various surfactants on properties of the polyethylene glycol (PEG)-Polymethyl methacrylate/Fe-2Ni feedstock are studied. First, one-molecule-layer model is used to calculate theoretically amount of surfactant needed to form onemolecule-layer absorption on powders. Then, different kinds of surfactants , such as, stearic acid, span-20, span-80, tween-60 etc., are added into the binder respectively. It was found that the surfactants increase the maximum powder loading by decreasing contact angle between the binder and the powder, and viscosity of the feedstock. Even the amount of surfactant is much higher than that of one-molecule-layer absorption, the surfactant still have its effective function. The effects of different kinds of surfactants on the properties of feedstock are not the same. By selecting a proper surfactant, the maximum powder loading can reach 55% (volume fraction)for Fe-2Ni carbonyl powder and PEG--based binder.