Compatibility studies of polypropylene (PP)-sago starch (SS) blends using DMTA

Sage starch (SS) was melt-blended with polypropylene (PP) with the concentr ation of SS in the blends varied between 10% and 50% by weight. Characteriz ation of the PP/SS blends was carried out to gain some information on the m iscibility between PP and SS and to gain insight into how well these materi als behave thermodynamically with regard to the variation of the storage mo dulus (E') and the loss tangent (tan delta) with temperature. The E' and ta n delta remained unchanged for SS between 10% to 33% but increased as SS re ached 50%. The blend containing 50%SS was superior compared to the other bl ends in the dynamic mechanical thermal analysis (DMTA). Through the use of a Differential Scanning Calorimeter (DSC), the melting endotherm of the mis cible blends was found to increase constantly with the increasing SS conten t. The tensile properties of the blends decreased with SS content. Examinat ion of the blends with a Scanning Electron Microscope (SEM) showed that the SS granules were well dispersed in the PP matrix.