Improved controlled relative humidity dynamic mechanical analysis of artists' acrylic emulsion paints - Part II. General properties and accelerated ageing

After improvements were made to a modified Polymer Labs MkIII DMTA instrument to facilitate repeatable controlled humidity (RH) experiments using isothermal and thermal scanning conditions, the viscoelastic properties of titanium white pigmented artists' acrylic emulsion films were measured in tensile mode. The effects of temperature, relative humidity and accelerated ageing regimes on two brands of titanium white paints were explored. These paints are highly responsive to changes in temperature and relative humidity, formulation differences affect properties slightly, and while light ageing had a negligible effect, thermal ageing resulted in decreased storage modulus and increased film density.