Influence of coating rheology on final coating properties

The paper reports the effects of addition of an associative thickener on th e viscoelastic properties of a wet coating and on dry coating bulk. As the concentration of a hydrophobic thickener increases, wet coating elasticity increases and the final dry coating void fraction increases. A logarithmic equation describes the relationship between elastic modulus and the void fr action and light scattering coefficient. The relationship results from incr eased network strength caused by the polymer. This increased strength incre ases the elastic modulus in the wet state and helps the coating components withstand stresses during coating consolidation. The strengthening results in a direct relationship between the viscoelasticity of the wet coating sus pension and the dry coating bulk. This relationship depends on the coating solids, Increasing solids increases the elasticity of the coating but decre ases the coating bulk. This work is the first attempt to quantify the relat ionship between suspension elasticity and dry coating bulk.