| Abstract: | Continuous copolymerization is used in order to achieve a product of uniform composition. However, it is difficult to attain high conversions without resorting to very high residence times in a single tank. The way to avoid this is to use a series of stirred reactors with addition of one comonomer and initiator to each one after the first. The allowable half-life of the initator is a function of the residence time. When all the reactors are equal in volume so that the residence time is the same in each, it can be shown that the incremental conversion in each successive reactor must decrease in a well-ordered manner. As a specific example, a copolymerization is postulated with total polymer concentration restricted to the region where viscosity is manageable with conventional mixing equipment. Under these conditions the relative reactivity ratios are presumed to be constant and temperature can be held within narrow bounds. |
