Abstract: Mg(OH)₂ whiskers that are surface-modified by sodium stearate and potassium oleate and PVC plastics were made into an Mg(OH)₂ whiskers/PVC composite.The effect of Mg(OH)₂ whiskers' content and distribution on PVC's mechanical properties were studied.The results show that surface-modified Mg(OH)₂ whiskers can be distributed homogeneously in PVC plastic; when the Mg(OH)₂ whiskers amount to 30% of the composite，the PVC composite has the best mechanical properties，with the elastic modulus improved by 41.18% compared with that of pure PVC plastics, and reaching 0.24 GPa.The main reason for this is that Mg(OH)₂ whiskers that are uniformly distributed assume the load transfer in the composite.

Key words: Magnesium hydroxide whiskers, PVC, Composite, Mechanical properties