MODELING OF MASS-EXCHANGE OF VOLATILE ORG ANIC-COMPOUNDS IN HIGH-VISCOSITY MEDIA

Polymers may contain low-molecular weight organic components as a resu lt of incomplete reaction during polymerisation, contamination of the reactants, and undesired side reactions. Aqueous of polymers are usual ly applied to surfaces (emulsion paints, adhesives, paper finishing ag ents, etc.). Since low molecular components then escape into the air, they are removed after polymerisation by stripping product with an ine rt gas. While the engineering used for this step is well developed, th e mass transfer processes involved have received little yet controvers ial attention. This paper presents a mechanistic mathematical model wh ich includes the transfer steps occurring during stripping in a statio nary continuously operating apparatus with complete back-mixing. Measu rements of the position of phase equilibria and determination of the d epletion achievable in an aerosol jet loop reactor demonstrate that, p rovided that the temperature of treatment exceeds the glass transition temperature, the stripping process is determined solely by the partit ion coefficients of the exchanged components between the phases, the h ydrodynamic parameters, and the reactor operating conditions. This con tradicts the claims of some authors that diffusion processes in the la tex particles are of decisive importance.