Sustainable and recyclable thermosets with performances for high technology sectors. An environmental friendly alternative to toxic derivatives

This study focuses on the development of environmentally friendly and chemically recyclable thermosets using or a renewable based monomer, the triglycidyl ether of phloroglucinol (TGPh), or a commercial non-toxic tris(4-hydroxyphenyl) methane triglycidyl ether (THPMTGE) monomer. The recyclable polyester thermosets were prepared by crosslinking the two monomers with hexahydro-4-methylphthalic anhydride (HMPA) or methyl nadic anhydride The TGPh-based formulations exhibited lower reaction temperatures and narrower reaction intervals. Additionally, these systems showed higher tan d values (189 degrees C-199 degrees C), higher crosslinking densities (7.6-7.8 mmol cm(-3)) and compact networks, crucial for high-performance industries. Tensile tests demonstrated the remarkable mechanical properties of the thermosets, including high Young modulus (1.3-1.4 GPa), tensile stress (55-69 MPa), and an elongation at break around 3%-8%. Moreover, the thermosets exhibited complete dissolution at a temperature of 170 degrees C, with depolymerization times of approximately 2.5 h for TGPh-based resins and 4.5 h for THPMTGE-based formulations. In conclusion, this study shows that sustainable and eco-friendly thermosets with excellent physico-chemical and thermo-mechanical properties, low hydrophilicity, and rapid dissolution capacity can be developed. These thermosets offer a viable alternative to non-recyclable and toxic resins in high-end industrial applications.