Facile elaboration of polymethylmethacrylate/polyurethane interpenetrating networks using Diels-Alder reactions
Résumé
Thermo-reversible PMMA/PU interpenetrating polymer networks were successfully prepared by Diels-Alder (DA) reaction using a furan-functionalized polymethyl methacrylate, furan-functionalized polyurethane and a maleimide-based coupling agent. First, homo-networks were synthesized and characterized in order to predict the characteristics of the corresponding interpenetrating network. Polyurethane networks were confirmed to be reversible with a temperature of retro-Diels-Alder varying from 135 degrees C to 144 degrees C depending on the cross-linking density. PMMA/PU blends are completely immiscible as shown by the presence of two Tgs corresponding to the two phases in DSC results. Due to the presence of supramolecular interactions, no phase separation was observed in the simultaneously cross-linked PMMA/PU networks. Thermal behavior and de-cross-linking of the IPNs were studied by DSC, solubility tests and rheology. Swelling tests allowed the evaluation of the networks density.