Eduardo Díez

Turbidimetric and intrinsic viscosity study of EVA copolymer–solvent systems

Both Hansen solubility parameter and Flory–Huggins interaction parameter of two EVA [Poly(ethylene-co-vinyl acetate)] copolymers with different vinyl acetate content have been obtained by means of intrinsic viscosity measurements. To calculate this last parameter it was also necessary to determine the theta solvent at different temperatures of the two EVA copolymers with turbidimetric measurements. The results indicate that the vinyl acetate content is a variable which influences the composition of the theta solvent and Flory–Huggins parameter (the higher the vinyl acetate content, the lower the Flory–Huggins parameter), although its influence over the Hansen solubility parameter is almost negligible.

Bentonite as an Alternative Adsorbent for the Purification of Styrene Monomer: Adsorption Kinetics, Equilibrium and Process Design

Some problems have been reported regarding the purification of styrene monomer by adsorption onto alumina beds, making this process both difficult and expensive. A study of the adsorption equilibrium and kinetics of t-butylcatechol (TBC) and water onto an alternative adsorbent, bentonite, is presented herein. Experimental equilibrium and kinetic measurements onto silica gel and commercial alumina are also included in order to compare the equilibrium capacities and adsorption rates. In addition, process design and economic evaluation of the adsorption process using bentonite as an adsorbent are also included.