Material propertiesThermal behavior, dynamic mechanical properties and rheological properties of poly(butylene succinate) composites filled with nanometer calcium carbonate

PBS/nano-CaCO3 composites with various nano-CaCO3 weight fractions were prepared by melt blending. The thermal behavior, dynamic mechanical properties and rheological properties of the composites were investigated. DSC measurements revealed that the nano-CaCO3 particles had little influence on the crystallization and melting behavior of PBS. Thermogravimetric analysis showed that the introduction of nano-CaCO3 tended to improve the thermal stability of PBS. Dynamic mechanical analysis showed that the G′ and G″ of the PBS/nano-CaCO3 composites were improved significantly when the nano-CaCO3 content was not more than 3wt%, while the G′ and G″ were mainly decided by the PBS matrix when the nano-CaCO3 content exceeded 3wt%. Rheological results showed that G′ < G″ over the frequency range, illustrating the viscous behavior of the samples. The η* of all the samples remained almost constant when the frequency was not more than 0.25 rad/s, which showed the characteristic of a Newtonian fluid. A strong shear thinning effect was observed for all the samples when the frequency exceeded 0.25 rad/s. Furthermore, the microstructure and the relaxation mechanism of the PBS/nano-CaCO3 composites mainly depended on the PBS matrix.