Chemical and mechanical reprocessed resins and bio-composites based on five epoxidized vegetable oils thermosets reinforced with flax fibers or PLA woven
Résumé
Bio-epoxy resins based on five epoxidized vegetable oils were formulated with an arom. disulfide crosslinker with diacid functionality, 2,2'-dithiodibenzoic acid (DTBA), to obtain recyclable epoxy thermosets. Flax fibers (FF) and PLA woven were used as bio-based reinforcements for these matrixes. Different percentages of reinforcement were tested and the effect of the natural fibers on the matrix's crosslinking reaction was studied by DSC anal. Then, the obtained materials were analyzed by differential scanning calorimetry, thermogravimetric anal., dynamic mech. anal., water absorption and SEM. The reinforcements improved the thermal and mech. properties of the neat resins, with tan δ values varying from 91 to 148°C showing a good compatibility matrix-FF but a reduced one in case of matrix-PLA woven. The dynamic nature of the networks crosslinking allowed the chem. and mech. recycling of both resins and bio-composites. Moreover, the obtained results show the possibility to recuperate the natural FF filler for the prepn. of second-life generation bio-composites.