Mathematical model styrene

Considerable work has been done on mathematic models of the extmsion process, with particular emphasis on screw design. Good results are claimed for extmsion of styrene-based resins using these mathematical methods (229,232). With the advent of low cost computers, closed-loop control of... 

Dente and Ranzi (in Albright et al., eds., Pyrolysis Theory and Industrial Practice, Academic Press, 1983, pp. 133-175) Mathematical modeling of hydrocarbon pyrolysis reactions Shah and Sharma (in Carberry and Varma, eds., Chemical Reaction and Reaction Engineering Handbook, Dekker, 1987, pp. 713-721) Hydroxylamine phosphate manufacture in a slurry reactor Some aspects of a kinetic model of methanol synthesis are described in the first example, which is followed by a second example that describes coping with the multiplicity of reactants and reactions of some petroleum conversion processes. Then two somewhat simplified industrial examples are worked out in detail mild thermal cracking and production of styrene. Even these calculations are impractical without a computer. The basic data and mathematics and some of the results are presented. 

Choi et al. [53] have successfully used both water-soluble and oil-soluble initiators in the miniemulsion polymerization of styrene. Alducin and Asua [119] have studied the MWD of polystyrene miniemulsion polymerized with oil-soluble initiators. Rodriguez et al. [61] have developed a mathematical model of seeded miniemulsion polymerization with oil-soluble initiator. Blythe et al. [ 120] have successfully carried out miniemulsion polymerization of styrene with AMBN (oil-soluble). Ghazaly et al. [117] have used AIBN for the miniemulsion copolymerization of a hydrophobic bifunctional macromer. The polymerization progressed much faster when KPS was used than when AIBN was used. This may be due to the tendency of oil-soluble initiator radicals to recombine before initiating polymerization, as discussed by Luo. 

The objective was to develop a model for continuous emulsion polymerization of styrene in tubular reactors which predicts the radial and axial profiles of temperature and concentration, and to verify the model using a 240 ft. long, 1/2 in. OD Stainless Steel Tubular reactor. The mathematical model (solved by numerical techniques on a digital computer and based on Smith-Ewart kinetics) accurately predicts the experimental conversion, except at low conversions. Hiqh soap level (1.0%) and low temperature (less than 70°C) permitted the reactor to perform without plugging, giving a uniform latex of 30% solids and up to 90% conversion, with a particle size of about 1000 K and a molecular weight of about 2 X 10 . 

A mathematical model for styrene polymerization, based on free-radical kinetics, accounts for changes in termination coefficient with increasing conversion by an empirical function of viscosity at the polymerization temperature. Solution of the differential equations results in an expression that calculates the weight fraction of polymer of selected chain lengths. Conversions, and number, weight, and Z molecular-weight averages are also predicted as a function of time. The model was tested on peroxide-initiated suspension polymerizations and also on batch and continuous thermally initiated bulk polymerizations. 

Bamford et al. ( 1 ) have presented the basic kinetics for free-radical polymerization of styrene, and Hamielec et al., (2 ) employing Bamford s nomenclature, developed differential equations that are the starting point for the mathematical model. 

Macaluso (USA) 1996 Use of work areas, historical changes, and mathematical models to obtain cumulative exposure estimates at six North American rubber manufacturing plants 1,3-Butadiene, styrene, benzene ppm-yr... 

The role of sulphur-containing compounds in photopolymerization appears to have attracted some interest. Bis(j -methylpyridazinyl)-3,3 -disulphide has been found to initiate the photopolymerization of styrene but inhibits the thermal polymerization. The role of thiyl radicals (PhS-) in photoinitiated polymerization of vinyl monomers by aromatic thio-compounds has been postulated by several workers. In one study, flash photolysis was used to identify the nature of the radical. Sulphur-containing monomers such as 4-methyl-2-(vinylthio)thiazole and thiocyclanes have been photopolymerized and copolymerized with other vinyl monomers. Luca et al. have devised a mathematical model for the photopolymerization of 2,3-dimethylbutadiene and thiourea. 

Case Study 2 Comparison of Mathematical Models FOR Free Radical Homopolymerization of Vinyl Monomers in scCOj In this case study, a comparison of performance of the different kinetic models proposed in the literature for dispersion polymerization of styrene and MMA in SCCO2 is presented. The models used by Quintero-Ortega et al. [43] (models 1 and 2) and those presented by the groups of Kiparissides [47] (model 3) and Morbidelli... 

Strategies for controlling the copolymer composition and MWD of latices based on linear and non-linear copolymers, such as styrene/butyl acrylate copolymers and methyl methacrylate/n-butyl acrylate copolymers, are described. These strategies involve on-line procedures based on calorimetric measurements and open-loop processes employing a mathematical model for determining the trajectories of the manipulated variables, such as monomer feed flow rates and chain transfer agent. 35 refs. (3rd lUPAC-Sponsored International Symposium on Free-Radical Polymerization Kinetics and Mechanism, II Ciocco (Lucca), Tuscany, Italy, 3rd-9th June, 2001)... 

In this section, effects of the current nonreactive version coil-globule transition in the FRRPP process was introduced using thermodynamic, transport phenomena, and kinetic concepts. Mathematical modeling efforts were applied to the polystyrene/styrene/ether system. This involved a probe into the model predictions... 

Temperature and free-radical concentration are important features that vary along the length of the plug-flow tubular reactor model of the polymerization of ethylene/ Stirred-tank reactor models of the anionic polymerization of styrene and of butadiene have been described and tested against experiments. Mathematical modelling of polymerization reactions receives some attention in the book by Froment and Bischoff. ... 

MATHEMATICAL MODELING FOR A STYRENE MONOMER TUBULAR REACTOR... 

We desire to develop a mathematical model for a styrene monomer pilot plant. The process flow sheet is shown in Figure 6.7. Ethylbenzene is passed through a tubular reactor packed with an iron oxide catalyst, and... 

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