Modeling the rheology of anaerobic adhesive formulations

In a previous paper. the influence of the two typical major components of anaerobics (fumarate-based thickeners and low-molecular-weight poly(ethylene glycol) dimethacrylate monomers) oil the blend rheology was studied. The blends obtained showed pseudoplastic behavior, and their viscosity at room temperature was established using the Cross equation as a function of the composition and the shear Fate. In addition, the evolution of the zero shear rate viscosity as a function of the thickener weight fraction was studied. and it was shown that two critical concentrations were present. This work has focused oil three-component formulations. based on the two previous components plus a thixotropic agent: fumed silica. Various fumed silicas were evaluated and they showed a significant effect oil the blend pseudoplasticity even at low concentrations. In addition. the mixtures showed both the Bingham effect and thixotropy. These formulations were modeled using non-phenomenological equations. Finally, a method based on the previous models has been proposed to estimate the flow behavior in actual dispensing equipments.