Effect of Calcium Carbonate Whisker Content on the Morphology, Crystallization, and Mechanical Properties of Poly(para-dioxanone)/Calcium Carbonate Whisker Composites

In this work, poly(para-dioxanone) (PPDO) was mixed with 0, 1, 5, 10, 20, and 30 weight percent (wt%) calcium carbonate (CaCO3) whiskers by solution coprecipitation. Samples were compression molded into bars using a platen vulcanizing press. It has assessed the influence of the CaCO3 whisker content on the morphology, thermal, mechanical, and crystalline properties of the PPDO/CaCO3 whisker composites, using differential scanning calorimetry (DSC), polarized optical microscopy, scanning electron microscopy, and Xray diffraction. DSC showed that the glass transition temperature (T-g) and crystallization temperature (T-c) of the composites increased with increasing CaCO3 whisker content. At low CaCO3 whisker content (1 wt%), the degree of crystallinity (Dc) of PPDO increased sharply. The addition of higher content of CaCO3 whisker would cause more agglomeration in PPDO matrix, so that the mechanical properties of PPDO/CaCO3 whisker composites would gradually decrease. The mechanical properties of PPDO were changed by the presence of CaCO3 whiskers; the optimal amount of CaCO3 whisker was 1 wt%, which sharply improved the tensile strength of PPDO by 54%. (C) 2015 Society of Plastics Engineers