Particle size distribution control in emulsion polymerization

Abstract

Effects of the operating policies-the initial initiator amount; the initial emulsifier amount; the monomer addition mode: batch or semibatch; and the monomer addition rate under "monomer-starved conditions" for the control of particle size distribution (PSD)-were studied through a model that simulates batch and semibatch reactor operations in conventional emulsion polymerization. The population balance model incorporates both the nucleation stage and the growth stage. The full PSDs were reported, which have normally been omitted in earlier studies. It was shown through simulations that the broadness of the distributions, both initial (obtained after the end of nucleation) and final (after complete conversion of monomer), can be controlled by the initial initiator amount and the emulsifier amount. The higher initiator amounts and the lower emulsifier amounts favor narrower initial and final distributions. The shape of the initial PSDs and the trends in the average size and range were preserved with subsequent addition of monomer in the batch or in the semibatch mode, although the final PSD was always considerably narrower than that of the initial PSD. The addition of monomer in the semibatch mode gave narrower distribution compared to that of the batch mode, and also, lower monomer addition rates gave narrower distributions (larger average sizes), which was a new result. It was further shown through simulations that, under monomer-starved conditions, the reaction rate closely matched the monomer feed rate. These conclusions are explained (1) qualitatively-the shorter the length of the nucleation stage and the larger the length of the growth stage (provided the number of particles remains the same), the narrower is the distribution; and (2) mathematically-in terms of the "self-sharpening" effect. Experimental evidence in favor of the self-sharpening effect was given by analyzing the experimental particle size distributions in detail. The practical significance of this work was proposed.

Is Modeling the PSD in Emulsion Polymerization a Finished Problem? An Overview

“…Hosseini et al [210] Sty 0-1 N Y Hosseini et al [23] Sty PB N Y Immanuel et al [211] VAc/BA PB N Y Immanuel et al [212] VAc/BA PB Y Y Jung and Gomes [26] Sty, BA 0-1/PB Y Y Kammona et al [213] Sty/2-EHA PB Y Y Kiparissides et al [214] VCM PB Y Y Marinangelo et al [215] Sty/BA PB N Y Meadows et al [216] Sty 0-1 N N Melis et al [217] VCM PB Y N Park et al [218] VAc/BA PB Y N Pohn et al [219] Sty 0-1 Y N Rajabi-Hamane and Engell [220] Sty PB N N Sajjadi [221] Sty 0-1-2-3 N Y Saldívar et al [4,[222][223][224] various binaries PB N Y Sood [225] Sty PB N N Sood [226] Sty PB N Y Sweetman et al [227] VAc/BA PB Y N Unzueta and Forcada [174] MMA/BA PB Y Y Vale and McKenna [38] VCM 0-1-2 Y Y Wulkow and Richards [228] -0-1-2 N Y Zeaiter et al [158,229] Sty…”

Inferência Por Redes Neurais Da Distribuição De Tamanho De Partícula Em Reações Contínuas De Polimerização Em Emulsão

“…Reator semi-batelada. Sood, (2004) Investigar o comportamento da DTP em reatores de polimerização em batelada e semi-batelada. Colocação ortogonal em elementos finitos é usada para resolver o modelo, sendo este usado para investigar os efeitos do controle operacional da quantidade inicial de iniciador e surfactante sobre a DTP.…”

Inferential closed-loop control of particle size distribution for styrene emulsion polymerization

“…When droplets phase exits (in intervals I and II or V d > 0) concentration of monomer in the particle and aqueous phases and phase volumes are calculated from the following equations (Sood, 2004;Edouard et al, 2005;:…”

“…Some published works have considered open-loop control of PSD in emulsion polymerization (Doyle et al, 2003;Doyle, 2002, 2003a;Sood, 2004). Using the open-loop strategy for PSD control is very sensitive to model uncertainties and disturbances.…”