"Regulation of bound acrylonitrile content of nitrile rubber with low acrylonitrile content"

Abstract

The factors affecting the bound acrylonitrile content of NBR product during the polyme-rization process were investigated, including monomer reactivity ratio, monomer conversion, monomer concentration, and polymerization temperature and pressure, the structural composition of the product was analyzed, and the polymerization reaction kinetics and repeatability experiment were carried out. The results showed that under the polymerization temperature of 5.0 ℃ and polymerization pressure of 0.15-0.20 MPa, NBR products with uniform distribution of acrylonitrile structure units and mass fraction of bound acrylonitrile of 17%-19% could be obtained by using multi-stage addition of acrylonitrile and controlling the monomer conversion of 70%-75%. The polymerization formula and process had good repeatability.

Keywords

• nitrile rubber
• bound acrylonitrile content
• monomer reactivity ratio
• monomer conversion
• monomer ratio