Safety in Emulsion Polymerization Reactors: An Experimental Study

The risk parameters of the high-solids-content emulsion copolymerization of vinyl acetate/butyl acrylate/ acrylic acid (78.5/18.5/3 wt.-%) were studied. The effect of the polymer/monomer ratio, the total solids content, the initiator/monomer ratio, the non-swollen polymer particle size, and the process temperature on the onset temperature for runaway, the adiabatic temperature increase, and the maximum temperature and pressure achieved was studied. These data are needed to determine the safety limits for the variables of this system considering the worst case scenario; namely, a runaway reaction under adiabatic conditions. It was found that the onset temperature is always below the typical process temperature for this system (70-80 °C). Therefore, in the case of a cooling system failure (i.e., electrical failure) the runaway reaction will take place. Relatively high pressures (up to 6 bar) were monitored during the runaway.