Cajetan F. Cordeiro

Modeling of particle size distribution in emulsion co-polymerization: comparison with experimental data and parametric sensitivity studies

A detailed model for particle size distribution in a vinyl acetate/butyl acrylate emulsion co-polymerization system is developed, employing the pseudo-homopolymerization approach. Significant changes have been made in modeling the average number of radicals per polymer particle n. The partial differential equation describing the particle population (population balance equation) is discretized using orthogonal collocation on finite elements, and the complete system of differential algebraic equations is solved using DDASSL. Simulation results under semi-batch operations are described and model predictions are compared with experimental results generated from an experimental reactor. A parametric sensitivity study is described with connection to the issue of parameter identification.

Continuous process for the production of vinyl acetate‐ethylene emulsion copolymers

A lab-scale experimental program was conducted to determine the feasibility of producing vinyl acetate-ethylene (VAE) emulsion copolymers via a continuous reaction process, using poly(vinyl alcohol), or PVOH, as a protective colloid. A process configuration of multiple stirred-tanks in series was utilized. Comparisons were made between continuous and batch processes with regard to final-product properties. As expected, notable differences in the breadths of the particle-size distributions obtained via the two processes were observed. However, these differences did not appreciably alter product performance in tile-mortar applications (as measured by plywood-to-quarry-tile adhesive strengths). Additionally, for the continuous process, in-process and final-product samples were compared to determine how polymer properties varied with conversion.

Experimental studies of the sensitivity of particle size distribution in emulsion co-polymerization

The control of particle size distribution (PSD) in semi-batch emulsion polymerization necessitates the identification of the best manipulative variables, with a profound influence on the PSD. The candidate variables include the feed rate of the monomers, surfactants and initiators. The monomer feed predominantly affects the growth rate, but could also influence nucleation rates. The surfactant feed influences the rates of nucleation and coagulation. The initiator feed could influence the rates of nucleation and growth. This paper describes the effect of these manipulative variables on the evolution of PSD, as studied in an experimental reactor system.