作者：L. Zha*, Z. Fang
关键字：Polystyrene, CaCO3, compounding, densification, toughening
论文来源：期刊
具体来源：Polymer Composites, 2010.7, 31(7): 1258-1264
发表时间：2010年

The Archimedes’ principle and physical theory are attempted to analysis the densification and structure of the polystyrene (PS) composites by melt compounding with CaCO₃ having different particle size. The difference between the measured specific volume (n) and the theoretically calculated specific volume (n_mix), Dn=n-n_mix,can reflect the densification of the composites. It is clearly demonstrated that the polystyrene composites become more condensed with the reduction of the CaCO₃ particle size. Especially, when the content for nano-CaCO₃ achieves 2 wt%, the Dn value of the composites reaches the least which shows the best densification. Meanwhile, the glass transition temperature (T_g) reaches the maximum value of about 100ºC by differential scanning calorimetry (DSC) and thermal mechanical analysis (TMA), which indirectly reveals the composites microstructure more condensed. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) reveal that 2 wt% nano-CaCO₃ uniformly disperses in polystyrene composites. The CaCO₃ selected in this experiment has certain toughening effect on polystyrene. The impact and tensile strength increase with addition of nano-CaCO₃, but the elongation at break decreases. When nano-CaCO₃ content achieved 2 wt%, the impact and tensile strength present the maximum value of 1.63 KJ/m² and 44.5MPa, which is higher than the pure polystyrene and the composites filled with the same content of micro-CaCO₃.