02655nas a2200289   4500008004100000022001400041245008500055210006900140260000800209490000800217520171400225653001601939653003101955653002201986653001602008653001302024100002902037700002502066700001802091700002302109700002002132700002202152700002302174700003102197700001702228856012002245       2026                        eng d  a1022-135200aVanillin-based recyclable thermosets and their glass fiber reinforced composites0 aVanillinbased recyclable thermosets and their glass fiber reinfo  cJAN0 v2273 a<p>
	The accumulation of end-of-life plastic materials and composite reinforcement waste materials has brought much attention to developing sustainable alternatives and their re-processability. Incorporating covalent adaptable networks (CANs) into the crosslinked network bridges the concept of reversibility into the otherwise conventional non-reversible networks. This study investigates the structure-property relation in two reversible hardener systems derived from vanillin using Schiff base chemistry. The ``CAN'' systems were synthesized by condensation of vanillin with two amines, 4,4'-oxydianiline and tris(2-aminoethyl)amine, respectively, to form Va_ODA and Va_TAEA. The epoxy thermosets exhibited glass transition temperatures (T-g) of 125 degrees C and 115 degrees C, respectively, for Va_ODA and Va_TAEA, which is superior to most reversible vanillin-based systems reported. The vitrimer-thermosets exhibited promising mechanical and thermal properties, and reshaping abilities as a function of applied temperatures, indicating the dynamic nature of linkages. Chemical degradability was demonstrated by heating to 80 degrees C for 12 h in aqueous acidic medium or excess amine. The fabricated glass fiber composites exhibited good mechanical properties with tensile strength of 361 MPa and degradability in acetic acid/water mixture with a fiber recovery of &gt;98 %. The recovered glass fiber exhibited almost similar tensile strength as the virgin glass fiber, demonstrating its potential reusability. The epoxy vitrimers underwent mechanical reprocessing through hot-pressing, as well as chemical reprocessing via 3D printing and by regeneration of imine bonds to form an epoxy resin.</p>
10a3D printing10acovalent adaptable network10are-processability10aSchiff base10aVanillin1 aVeetil, Ashwani, Puthiya1 aRavikumar, Aniruddha1 aRajput, Tejas1 aSingh, Aman, Kumar1 aThakur, Tamanna1 aKrishna, Abhijith1 aPol, Harshawardhan1 aShanmuganathan, Kadhiravan1 aAsha, S., K.  uhttps://library.ncl.res.in/content/vanillin-based-recyclable-thermosets-and-their-glass-fiber-reinforced-composites