Polymer process
View Patent ↗Disclosed is a process for controlling the level of in-process monomer in an emulsion polymerization reaction. Also disclosed is a method of controlling particle size by controlling the level of in-process monomer.
1. A method of controlling standing monomer level in a polymerization reaction including the steps of a) detecting coolant temperature at a cooling jacket inlet; b) detecting coolant temperature at a cooling jacket outlet; c) detecting coolant flow rate; d) calculating Q jdyn (raw) and U raw wherein U raw is capped such that U min <U raw <U max ; e) obtaining U filt by inputting U raw into a low pass first order filter, f) calculating, using the values obtained in steps a through e, a value for the dynamic jacket heat removal; g) calculating a heat release value of polymerization using the dynamic jacket heat removal value; h) comparing the calculated heat release value of polymerization to a target heat release value of polymerization; i) calculating, using the value obtained in step h, the level of in-process monomer in the polymerization reaction; and j) controlling the rate of monomer addition to the polymerization reaction, based upon a comparison the value obtained in Step i with a target in-process monomer level, such that a desired level of in-process monomer is maintained.
2. The method of claim 1 wherein the polymerization reaction is an emulsion polymerization.
3. The method of claim 1 wherein the level of in-process monomer is less than about 8% wt, based on the total weight of the reaction mixture.