Compatibilization of PUR/PVAC polymer blend by addition of calcium carbonate filler

The influence of untreated and stearic acid surface pretreated calcium carbonate (CaCO ₃ ) nanofiller (U1 – untreated CaCO ₃ and U1S2 – stearic acid treated CaCO ₃ ) on the properties of polyurethane/poly(vinyl acetate) (PUR/PVAC) polymer blends was investigated. Adhesion between fillers and polymers in the polymer blend composite, and filler position in regard to the polymer phases, are predicted on the basis of calculated adhesion parameters and wetting factor ωa of PUR, PVAC, U1, and U1S2. U1 is located in the PUR matrix phase and U1S2 is located at the interface between matrix PUR domain and dispersed PVAC domain. Polymer blend composites with predominant U1S2 showed lower tensile strength and elongation compared to these of polymer blend composites with predominant U1 mainly due to the fillers' different surface properties, which confirmed that the mechanical properties of polymer blend composites were dependent on overall system morphology rather than the filler location. POLYM. COMPOS. 37:1274–1281, 2016. © 2014 Society of Plastics Engineers