The electrostatic compounding technology was used to prepare glass fiberSiO2 (GF-SiO2) and glass fiberMWNTs (GF-MWNTs) reinforcing fibers.Polyamide 6 (PA6)/GF-SiO2 and PA 6/GF-MWNTs composites were prepared by using a torque rheometer.The effects of compounded fibers on the mechanical

thermal properties and crystallization behavior of PA 6 were investigated via scanning electron microscope (SEM)

differential scanning calorimeter (DSC)

thermal mechanical analyzer (DMA) and tensile test.SEM photographs show that nano-SiO2 and MWNTs-COOH were uniformly dispersed on the surfaces of glass fibers.The interfacial adhesion between PA6 matrix and GF-SiO2

GF-MWNTs are better than that between PA6 and untreated GF due to the interaction such as hydrogen/covalent bonds formed among the functional groups of nano-particles and PA6 chains.Addition of GF and compounded fiber increased the crystallization temperature of PA 6

which indicated that GF and nanoparticles played the role of nucleating agent of PA 6.It was revealed that the PA 6/compounded fiber composites had higher tensile strength and dynamic storage modulus than those of PA 6/untreatedGF composites

especially the PA6/GF-MWNTs composites exhibited improved mechanical properties with 21% and 28% increases in tensile strength and dynamic storage modulus respectively.