Characterization of swelling behavior and elastomer properties of acrylate polymers containing 2-ethylhexyl and isobornyl esters

In this work, a comparative study of the swelling behavior of poly((1,7,7-trimethyl-2-bicyclo[2.2.1]heptanyl) prop-2-enoate) (poly(IBOA)) and its copolymer (poly(IBOA)-co-2-EHA)), prepared by radical polymerization with the addition of a low concentration of crosslinking agent and photoinitiator, was performed. The obtained networks were characterized by FTIR to show the conversion of acrylic band before and after polymerization and by differential scanning calorimetry. The copolymer network has a single glass transition temperature (T ) that decreases relative to the poly(IBOA). The swelling study of poly(IBOA-co-2-EHA) was carried out by gravimetric method, in a series of polar (methanol, ethanol, propan-1-ol, butan-1-ol, pentan-1-ol, hexan-1-ol and heptan-1-ol) and non-polar (toluene) isotropic solvents. Solubility, interaction and diffusion parameters that influence the swelling of copolymer in the solvents were calculated. The well-established order of swelling (toluene > heptan-1-ol > hexan-1-ol > pentan-1-ol > butan-1-ol > propan-1-ol > ethanol > methanol) in the copolymer was clearly observed, and moreover, the degree of swelling increased with the presence of EHA in the copolymer. A simple diffusion model was applied (Fick's model) to interpret the swelling data. It was found that the nature of solvent shifts the mechanism from diffusion-controlled in the case of alcohols to non-Fickian one for toluene. For a long period, the experimental results were well correlated with the second-order diffusion kinetics of Schott. Graphic abstract: [Figure not available: see fulltext.].