Nylon short fiber (NSF) and silica were used to fill natural rubber (NR) to prepare composites compatibilized by maleated natural rubber (MNR).Influences of NSF content on dynamic rheological behavior were discussed for the un-compatibilized and the MNR compatibilized NSF/NR compounds.The compatibilized NSF/NR masterbatch was added into NR filled with 30 phr silica

and dynamic rheological behavior of the compounds was investigated with respect to NSF content.The modified two phase model was used to analyze the enhancement effect offiller phaseconstructed by introducing NSF or by introducing both NSF and silica.The changes of storage modulus E' and loss factor tan of vulcanites were studied for clarifying influence of composition on dynamic mechanical behavior.It was indicated that MNR could efficiently enhance the compatibility between NSF and rubber matrix to improve the dispersion of fiber and to construct a strongfiller phasein comparison with that in the un-compatibilized compounds.Introduction of silica greatly improves both the elastic and the viscos contributions of thefiller phasewith a markedly reduced relaxation dynamics

the reinforcing factor and strain amplification factor of NR/NSF/SiO2 compounds were higher than those of NR/NSF compounds.Storage modulus and peak value of loss factor increased and decreased

respectively

with adding of NSF in the NR vulcanites.