| Affiliation: | 1. Univ. Lille, CNRS, INRAE, Centrale Lille, UMR 8207 – UMET – Unité Matériaux et Transformations, Lille, France
Laboratoire de Recherche sur les Macromolécules (LRM), Faculté des Sciences, Université Aboubakr Belkaïd de Tlemcen, Tlemcen, Algeria;2. Laboratoire Physico-Chimie des Matériaux-Catalyse et Environnement (LPCM-CE), Université des Sciences et de la Technologie d'Oran Mohamed Boudiaf (USTOMB), Oran, Algeria;3. Unité de Dynamique et Structure des Matériaux Moléculaires (UDSMM), Université du Littoral - Côte d'Opale (ULCO), Calais Cedex, France;4. Laboratoire de Recherche sur les Macromolécules (LRM), Faculté des Sciences, Université Aboubakr Belkaïd de Tlemcen, Tlemcen, Algeria;5. Univ. Lille, CNRS, INRAE, Centrale Lille, UMR 8207 – UMET – Unité Matériaux et Transformations, Lille, France |
| Abstract: | A series of linear acrylic copolymers based on Isobornyl acrylate (IBOA) and isobutyl acrylate (IsoBA) were elaborated by radical photopolymerization. In addition, several photochemically crosslinked poly(IBOA-co-IsoBA) were prepared by introducing small amounts of 1,6-hexanedioldiacrylate as crosslinking agent. The evolution of the glass transition temperature was determined experimentally by differential scanning calorimetry as a function of composition for both linear and crosslinked poly(IBOA-co-IsoBA), yielding Tg values ranging from (~249) to (~315 K). Theoretical modeling was performed applying Fox, Gordon-Taylor and Couchman-Karasz models by simple calculations using experimental data, leading to only fair agreement between theoretical and experimental values, or by applying fitting procedures involving one or two adjustable parameters. Likewise, the Kwei model, known to take into account hydrogen bonding interactions between monomers, could not describe well the evolution of Tg, indicating the existence of other factors influencing Tg. Finally, a thermodynamic approach based on entropy considerations allowed to attribute an explanation of the evolution of Tg. |
