Methacrylic Acid → Methyl Methacrylate

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A monomer emulsion was formed from 1397 g ethyl acrylate, 386 g methyl methacrylate (as well as <2% by weight of total monomer of methacrylic acid, sodium carbonate and n-dodecylmercaptan) with 499 g DI water and 51.8 g anionic surfactant (30% active) which was emulsified with stirring. 9 g anionic surfactant (30% active) and 547 g DI water were charged to a 4L multi-neck flask fitted with mechanical stirring. The flask contents were heated to 75° C. under nitrogen. To the stirred kettle contents were added 67 g monomer emulsion followed by 0.02 g ferrous sulfate heptahydrate and 0.02 g tetrasodium salt of ethylenediamine-tetraacetic acid in 23.5 g DI water and sodium carbonate (<0.5% based on total monomer). Polymerization was initiated by the addition of 1.2 g sodium persulfate in 36 g DI water followed by 0.6 g sodium hydrosulfite in 5 g DI water. Gradual addition of the monomer emulsion was subsequently initiated. Separate solutions of 3.8 g APS in 160 g DI water and 1 g of D-Isoascorbic acid in 160 g DI water were fed concurrently with the monomer emulsion. After half of the monomer was fed, 55 grams of a 50% solution of ureido methacrylate was added to the remainder of the monomer emulsion. Total addition time for the three feeds was 90-100 minutes. Reactor temperature was maintained at 75° C. throughout the polymerization. 32 g DI water was used to rinse the emulsion feed line to the reactor. After completion of the monomer emulsion addition, the reactor was cooled from 75° C. to 60° C. as the residual monomer was reduced by additional redox pair addition. The polymer emulsion was neutralized to pH 8 with sodium hydroxide solution. Less than 2% by weight of anionic surfactant and preservative were then added. Final particle size was 150 nm and solids content was 50%. The polymer is designated Polymer A.

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