Abstract: In order to reinforce the nitrile rubber（NBR）with the micro-talc powder，the effects of the particle size and the
content and the surface treatment by the silane coupling agent of the talc on the mechanical properties of NBR are studied in
this paper. It is shown that the talc has better reinforcement results when its particle size is very small with its optimal content
and NBR has the tensile strength of 13.5 MPa and the tearing strength of 41.4 kN/m when the talc has the particle size of 2500
mesh and the content of 60phr，and that the comprehensive properties of NBR can be further raised with the tearing strength of
14.1 MPa and the tearing strength of 48.1kN/m when the surface of the talc is treated by 1%（mass concentration）KH550，and
that the dispersivity and compatibility improved by KH550 between the talc and NBR have been verified through the SEM.

Key words: powder, talc powder, nitrile rubber, reinforcement, mechanical properties