PMMA thermoreversible networks by Diels-Alder reaction

Reversibly crosslinked polymethylmethacrylate were prepared by Diels-Alder (DA) reaction using multi-furan and multi-imide precursors. Furan functionalized PMMA were obtained by reactive extrusion (transesterification) between a commercial PMMA and furfuryl alcohol using tin(II)2-ethylhexanoate (Sn(oct)2) or 1,5,7-Triazabicyclo[4.4.0]dec-5-ene (TBD) catalysts. Maleimide based coupling agents were prepared by amine-anhydride reaction. Thermomechanical properties of the PMMA precursors and issued networks were analyzed. Two G′ and G″ cross-over temperatures were obtained during the heating and cooling cycles. The first one at 110 °C can be assimilated to physical gel formation and the second one at 160 °C to its breaking. When the network was formed, an increasing of these temperatures is observed. Also, the G′ between these temperatures increased with the network density. The obtained network had a shape memory behavior.