New hydrogenation process of HNBR with low Mooney viscosity

摘要

Hydrogenation reaction of two different base NBR are carried out with tris-(triphenylphosphane)-rhodium-chloride as catalyst and chlorobenzene as solvent, in which, both base NBR contain acrylonitrile 36% (wt), whereas molecular weight distribution (MWD) and Mooney viscosity [ML(1+4) 100℃] are different. The new process is developed by adding catalyst solution to vessel at relative lower temperature (50～55℃), premix for 30 min, reaction at (90±3)℃ and (7±0.3) Mpa. and compared with traditional process by charging at 60～65℃, then rising temperature step by step up to 120℃ at last, pressure increasing gradually from 5 MPa to 9 MPa final. Further than that, study on effects of different concentration of catalyst on ML and test properties of HNBR vulcanizates. The results show that MWD and ML of base NBR have a most affection on ML of HNBR; that is 75 and 83 by comparing new with traditional process respectively when using lower ML of base NBR to preparing HNBR of same hydrogenation degree (96%), on the contrary, the value above is changed to 105 and 122 respectively when using higher ML of base NBR; the properties of vulcanizates are not found difference obviously, especially compression set, based on two different NBR; hydrogenation reaction time with new process is about shorter 2 hr than that of traditional process; concentration of catalyst has also more influence on ML of HNBR.