Portal de Periódicos da CAPES

Studies in continuous polymerization

1952; Wiley; Volume: 9; Issue: 2 Linguagem: Inglês

10.1002/pol.1952.120090207

1542-6238

Frederick T. Wall, C. J. Delbecq, Roland E. Florin,

Thermal and Kinetic Analysis

Abstract The theory of continuous polymerization processes has been developed in a form that permits experimental verification. Under selected experimental conditions it has been found possible to predict the asymptotic, or steady state, conversion without recourse to any assumptions concerning the kinetic order of the polymerization reaction. The theory has been compared with results obtained for the continuous solution polymerization of styrene. Emulsion copolymerization of styrene and methyl methacrylate was carried out by a continuous process in the range 35–55°C. These polymerizations were extended over periods up to 48 hours and with the steady state conversions varying between 35 and 85%. The observation that the conversion passes through a maximum and then decreases somewhat to the steady state value has been found to fit in well with Harkins' picture of emulsion polymerization. A method for obtaining a composition fractionation of styrene‐methyl methacrylate copolymer was developed. Batch and continuous emulsion copolymers (obtained at 77% conversion) were fractionated by this method and it was established that the continuously prepared copolymer was compositionally more homogeneous than the other in spite of the complexity of emulsion polymerizations.