Making polymers colored and stiffer by dyed regenerated cellulose employing Pickering emulsions

We demonstrate the successful use of Pickering emulsions utilizing regenerated cellulose that carry covalently immobilized dye molecules as emulsifiers to color PMMA and enhance its mechanical performance. Due to the use of this biobased dye carrier, the materials we describe exhibit enhanced “green” character. First we show that oil-in-water Pickering emulsions of PMMA can be effectively stabilized by dyed regenerated cellulose. We describe how uniformly colored PMMA-cellulose composites with high transparency in the visible range can be obtained. We provide detailed characterization of the resulting composites. Thermogravimetric analysis shows an increase of onset of degradation temperature, thus indicates improved thermal stability. Also the mechanical properties become improved, as indicated by flexural strength enhancement. The Pickering emulsion-based procedure is simple and cost effective, and could be easily adopted to prepare other polymer-nanocomposite systems.