Application of Calorimetry Technique to Estimate Conversion of Polymerization Reactions in a Standard Lab-Scale Reactor

Reaction calorimetry is a very useful tool for monitoring exothermic polymerization reactions as it uses the measurement of the liberated energy to calculate the reaction rates. Despite the estimation of conversion for homopolymerizations being well established for commercial calorimetry reactors or lab-scale reactors specially constructed to operate as calorimetry reactors, it is still a challenge to use calorimetry to estimate conversion in standard lab-scale reactors. In the present work, a standard lab-scale jacketed stainless steel tank reactor with an internal volume of 5 liters was instrumented to operate as a calorimetric reactor. Water was used as the heating/cooling fluid and its flow rate was kept constant. The isothermal calorimetry and isoperibolic calorimetry were used to determine the conversion of batch vinyl acetate emulsion polymerization. Both results were compared and showed that, even at a relatively high residence time of the cooling fluid in the jacket (∼18 s) and significant heat loss, estimated conversions obtained by the measurements of reactor and jacket temperatures and by the mass and energy balances presented a good agreement with gravimetric data.