(202e) Mathematical Modeling of the Synthesis of Poly(acrylic acid) Hydrogels

Water-soluble polymers, or hydrogels, have received much attention in recent years due to their unique properties that allow them to be used in various areas. In particular, poly (acrylic acid) hydrogels are on focus because of their response to pH variations and the consequent availability to be applied drug delivery via oral route. Given this importance, this paper focuses on the mathematical representation of the synthesis of poly(acrylic acid) hydrogels. It was developed a kinetic model that represents the synthesis of copolymers of acrylic acid in aqueous solution, using trifunctional crosslinkers such as trimethylolpropane triacrylate. The main objective of this work was to obtain a better understanding of the behavior of this polymerization process. The model developed comprise mass balance equations for species, method of moments, numerical fractionation and a balance of sequences was made in order to take into account the cyclization reactions. The pseudo-steady state hypothesis was applied for species containing radical center. The method of numerical fractionation allows the determination of the gel fraction formed during the reaction and the weight average molecular weight of soluble chains in the post-gelation period. The present model was compared with approaches from literature and similar results were obtained. Experimental studies are underway in order to validate the model.