Towards the production of green/odorless latexes

摘要

The main aspects of post-polymerization and devolatilization for cleaning industrial latexes were analyzed. Monomer partitioning was studied and we found that most of the monomer was portioned into the polymer particles, independently of its water solubility. The knowledge of the mechanisms involved in monomer removal by post-polymerization allowed the development of a mathematical model, which was able to predict both, monomer removal and new VOCs formation when the very efficient organic hydroperoxides were used as initiators. Using this model, the optimal conditions for the removal of the residual monomer in a minimum process time and minimizing the production of new VOCs were determined. Devolatilization involves the mass transfer of monomers and VOCs from polymer particles to the aqueous phase and from this phase to the gas phase. The latter is the rate determining step. In this work, the effect of one of the variables involved in this stage, i.e., the gas flow rate on the devolatilization efficiency was studied, and the relationship between the minimum gas flow rate and total process time, needed to reach a known VOC content, was determined.