engleski

Effect of filler surface modification on properties of filled polyurethane / poly(vinyl acetate) blend

Blending of two polymers is an interesting field of investigations, both scientific and industrial, because it provides an effective route for obtaining materials with improved property/cost performances without the need to synthesize new polymers. Polyurethane (PU) and poly(vinyl acetate) (PVAc) are partially miscible polymers. The aim of this study was to investigate the influence of untreated and surface pretreated calcium carbonate (CaCO3) on interphase properties of the PU/PVAc polymer blends with possible compatibilisation effects when the conditions of effective adhesion are achieved. With the aim to modify the interface between filler and matrices, CaCO3 surface was pretreated by 3- aminopropyltriethoxysilane and after that by grafting of PVAc using 60Co γ -ray irradiation polymerization of vinyl acetate. A series of the PU/PVAc blends without and with the addition of CaCO3 were prepared using a Brabender plasticorder at 140°C. Surface characterization of the PU and PVAc polymers as well as the untreated and surface pretreated CaCO3 fillers was carried out by determination of surface free energy. The adhesion between CaCO3 and phases in the polymer blends as well as the position of the filler (with respect to the each phase) were predicted on the basis of calculated adhesion parameters (interfacial free energy, spreading coefficient and work of adhesion) and the wetting coefficient of blends. Thermal and mechanical properties were investigated by tensile strength measurements and differential scanning calorimetry (DSC). The adhesion parameters as well as the wetting coefficient were correlated with mechanical and thermal properties of the polymer blends.

filler surface modification; filled polyurethane / poly(vinyl acetate) blend

nije evidentirano