Author : Hugo Vale
Publisher :
ISBN 13 :
Total Pages : 200 pages
Book Rating : 4.:/5 (819 download)
Book Synopsis Population Balance Modeling of Emulsion Polymerization Reactors by : Hugo Vale
Download or read book Population Balance Modeling of Emulsion Polymerization Reactors written by Hugo Vale and published by . This book was released on 2004 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis is a contribution to the development of population balance models of emulsion polymerization and, more particularly, to the modeling of particle formation and particle size distribution (PSD) in vinyl chloride emulsion polymerization. The rst part of the work is dedicated to the acquisition of experimental data. Ab initio polymerizations were done to obtain reliable data regarding the dependence of the particle number on the concentration of surfactant, as well as to analyze the effect of the initiator concentration, stirring rate, and monomer-to-water ratio upon the particle number and the polymerization kinetics. In addition, seeded polymerizations were carried out at different concentrations of seed latex and emulsifier in order to quantify the influence of these factors on the onset and extent of secondary particle formation. Moreover, the adsorption isotherms of SDS and SDBS on poly (vinyl chloride) latex particles were determined. The second part of the manuscript focuses on the development of the population balance model. A special feature of the model proposed in this work is the computation of the coupled radical number and particle size distributions by the zero-one-two population balance equations. Overall, the examples presented show that the model can capture the tendencies observed in the polymerizations with physically reasonable values of the unknown/ adjustable parameters. With respect to particle formation, it was seen that including the possibility of particle nucleation (homogeneous and micellar) by exited radicals helps to explain the high particle numbers observed and the fact that the initiator concentration has a negligible effect on the particle number. Moreover, it was demonstrated that particle coagulation must be taken into account in order to obtain plausible PSDs and to avoid the use of abnormally low values of the efficiency of radical entry into micelles. In the third and last part, two novel numerical methods for the solution of population balances of interest to emulsion polymerization systems are presented and discussed.
