Preparation and properties of cellulose/PE-co-AA blends

Cellulose/polyethylene-co-acrylic acid blends (cellulose concentration 0-50 wt.%) was prepared via mixing their alkaline solutions. The formed suspension was precipitated and dried, where after the morphology as well the thermal and mechanical properties of the blends were characterized by Differential Scanning Calorimetry (DSC), Scanning Electron Microscopy (SEM), and Dynamic Mechanical Analyses (DMA). In addition, the melt properties of the blend were studied by rotational rheometer following some injection molding trials as well. The polymers were found to be dispersed homogenously in the blend and the crystallization temperature of the PE-co-AA phase was increased similar to 6 degrees C due to the nucleation ability of the cellulose phase. The size of the discontinuous cellulose phase was 5 mu m at the most while at higher cellulose concentrations (30-50 wt.%) the polymers formed co-continuous morphology in the blend. This change in the morphology was observed also in their melt properties which showed that the blend reached so called percolation point at similar to 20 wt.% of cellulose. Finally, the blends were found to be injection moldable over the whole composition range, if only the injection molding became more challenging (i.e. higher mold temperatures and longer mold cooling times were required) after the percholat ion point. (C) 2012 Elsevier Ltd. All rights reserved.