Study on the Crystalline Structure and Crystallization of PP/nano-SiO_2 Composite

Crystal structure and characteristics of three polypropylene/nano-SiO-2(PP/nano-SiO-2) composites with different surface-treated SiO-2 are observed and studied by polarizing microscope and DSC respectively.Results show that nano-SiO-2 acts as a nucleation agent in PP and heterogeneous nucleation domains during the crystallization,thus upgrading the crystal temperature and nucleation rate.The spherulites of the crystal become small and even,but basically there is little effect on crystalline degree and melt point.The finer the nano-SiO-2 is,the more even the dispersion is.The same phenomenon occurs while increasing the content of nano-SiO-2.The surface treatment of nano-SiO-2 has obvious influence on crystal structure characteristics of the system.It is concluded that nano-SiO-2 functions as a reinforcing and toughening agent.