Two=stage, bulk polymerisation of vinyl chloride - with addition of ammonia to give polymer of low colouration

摘要

In a 2-stage, bulk (co)polymsn. of vinyl chloride in which the monomer is first prepolymerised to 5-15% conversion under high shear and then, after opt. addition of more monomer, polymsn. is completed under reduced shear, the improvement consist in introducing NH3 into the reaction medium before the residual vinyl chloride in the (co)polymer has been reduced below 200 ppm. A (co)polymer of weak colouration is produced.