02056nas a2200241   4500008004100000022001400041245009200055210006900147260000800216300001400224490000700238520127500245653001601520653002801536653001401564653000901578100001801587700001601605700001901621700001901640700003101659856012401690       2026                        eng d  a0969-023900aSimple two-step gelation process to strengthen 3D printed carboxy methyl cellulose gels0 aSimple twostep gelation process to strengthen 3D printed carboxy  cMAR  a2015-20300 v333 a<p>
	Carboxymethyl cellulose (CMC) is a water-soluble cellulose ether that is widely utilized in hydrogel applications due to its exceptional water absorption and biocompatibility. This study reports a simple two step strategy to make mechanically robust CMC gels without any additional chemical crosslinkers and how it could be leveraged to strengthen 3D printed CMC gels. These hydrogels, prepared through acid-induced gelation followed by freeze-thawing, exhibited a compressive modulus of 12.4 +/- 0.92 kPa and a compressive strength of 491.0 +/- 18.1 kPa. They could be leveraged for strengthening 3D printing hydrogels of intricate shapes by direct ink writing. Small amplitude oscillatory shear (SAOS) tests indicated an order of magnitude higher storage modulus for freeze-thawed gels (FC) as compared to only acid-induced CMC gels (HCMC). Nonetheless, stress relaxation experiments revealed that FC, as well as HCMC gels, relax at similar time scales. FC gels exhibited clear birefringence under crossed polarizers, indicating molecular ordering that is consistent with the presence of ordered/crystalline domains. Such ordered domains likely contribute to the higher elastic modulus and compressive strength observed in FC gels as compared to HCMC gels.</p>
10a3D printing10aCarboxymethyl cellulose10acellulose10aGels1 aRajput, Tejas1 aSathe, Asmi1 aGopal, Animesh1 aSharma, Aakash1 aShanmuganathan, Kadhiravan  uhttps://library.ncl.res.in/content/simple-two-step-gelation-process-strengthen-3d-printed-carboxy-methyl-cellulose-gels02655nas 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