A Continuous Bulk Polymerization Process for Crystal Polystyrene

Abstract A proposed styrene polymerization process for the production of crystal polystyrene is evaluated. The present process consists of an autorefrigerated stirred tank, followed by a tubular reactor. A flash tank devolatilizer is then used to remove volatiles from the reactor effluent. A mathematical model has been developed to include three different types of polymerization reactors: (i) polymerization in a stirred tank, (ii) polymerization in a plug flow reactor, and (iii) polymerization in a real tubular reactor. The styrene conversion and polystyrene quality were determined as a function of temperature and residence time in a reactor. It was found that an ideal process would be prepolymerization in a stirred tank to a 70–75% conversion, followed by postpolymerization in a tubular static mixer to 90% conversion. The pipe has an internal diameter of 0.254 m. Equilibrium considerations were used to estimate the content of residual volatiles in the devolatilized polystyrene melt. The results show that...

[1]  J. Wallis,et al.  Continuous production of polystyrene in a tubular reactor: Part I , 1975 .

[2]  B. Finlayson.  Nonlinear analysis in chemical engineering , 1980 .

[3]  Curtis F. Gerald,et al.  APPLIED NUMERICAL ANALYSIS , 1972, The Mathematical Gazette.

[4]  L. S. Henderson.  Stability analysis of polymerization in continuous, stirred-tank reactors , 1987 .

[5]  R. H. M. Simon,et al.  Technology of Styrenic Polymerization Reactors and Processes , 1979 .

[6]  A Method for Viscosity Measurements of Concentrated Polymer Solutions in Volatile Solvents at Elevated Temperatures , 1979 .

[7]  A. Husain,et al.  Thermal polymerization of styrene , 1978 .

[8]  R. Mendelson.  Concentrated Solution Viscosity Behavior at Elevated Temperatures—Polystyrene in Ethylbenzene , 1980 .

[9]  G. Astarita,et al.  DEVOLATILIZATION OF POLYMERS , 1993 .

[10]  C. Denson.  Stripping Operations in Polymer Processing , 1983 .

[11]  J. S. Vrentas,et al.  Thermodynamic properties of some amorphous polymer-solvent systems , 1983 .

[12]  J. A. Biesenberger,et al.  Principles of Polymerization Engineering , 1983 .

[13]  A. Hui,et al.  Thermal polymerization of styrene at high conversions and temperatures. An experimental study , 1972 .

[14]  R. S. Spencer,et al.  Concentrated solution viscosity of polystyrene , 1947 .

[15]  Albert Renken,et al.  BULK POLYMERIZATION OF STYRENE IN A STATIC MIXER , 1983 .

[16]  P. Flory.  Principles of polymer chemistry , 1953 .

[17]  W. Scheiber,et al.  The Density, Thermal Expansion, Vapor Pressure, and Refractive Index of Styrene, and the Density and Thermal Expansion of Polystyrene , 1939 .

[18]  P. Ku.  Polystyrene and styrene copolymers. I. Their manufacture and application , 1988 .