GRAFT CO-POLYMERIZATION OF LIGNOSULFONATE AND STYRENE

A study was made of the graft copolymerization of calcium lignosulfonate with styrene. Heterogenous copolymerization were carried out with methanol as swelling medium, using ferrous ion as catalyst, and ozone and/or hydrogen peroxide as initiator. When using peroxide alone as initiator, monomer conversion was low; after ozonization of lignosulfonates, monomer conversion increased considerably and the grafting efficiency, as well as degree of lignosulfonate grafted, was improved. At 55°C, a 10‐fold increase in conversion was observed for reactions with ozone‐pretreated lignosulfonates. The investigated factors that affected the graft copolymerization were: the amount of peroxide and ozone charged, the reaction temperature and the ratio of styrene/methanol. Copyright © 1979 John Wiley & Sons, Inc.