High-performance acetosolv lignin-incorporated DGEBA cured with aprotic imidazolium-based ionic liquid: Polymerization, chemical, thermal and combustion aspects of the thermosetting materials.

The lignin valorization constitutes a chemical platform for several segments of chemical industry. The aim of this work was to evaluate the potential of acetosolv coconut fiber lignin (ACFL) as an additive to DGEBA, curing it using an aprotic IL ([BMIM][PF6]) and analyze the properties of the obtained thermosetting materials. ACFL was obtained by mixing coconut fiber with 90 % acetic acid and 2 % HCl at 110 °C during 1 h. ACFL was characterized by FTIR, TGA and 1H NMR. The formulations were fabricated by mixing DGEBA and ACFL at different concentrations (0-50 % wt.). The curing parameters and [BMIM][PF6] concentrations were optimized by DSC analyses. The cured ACFL-incorporated epoxy resins were characterized by gel content (GC), TGA, MCC and chemical resistance in different media. ACFL undergone a selective partial acetylation that favored its miscibility with DGEBA. High GC values were obtained at high curing temperatures and ACFL concentration. The crescent ACFL concentration did not affect the Tonset of the thermosetting materials significantly. ACFL has increased the resistance of DGEBA to combustion and different chemical media. ACFL has shown a great potential to be used as a bio-additive for enhancing the chemical, thermal and combustion properties of high-performance materials.

Development of a phosphorous-based biorefinery process for producing lignocellulosic functional materials from coconut wastes.

This work aimed to develop a phosphorous-based biorefinery process for obtaining phosphorylated lignocellulosic fractions in a one-pot protocol from coconut fiber. Natural coconut fiber (NCF) was mixed with 85 % m/m H3PO4 at 70 °C for 1 h to yield the modified coconut fiber (MCF), aqueous phase (AP), and coconut fiber lignin (CFL). MCF was characterized by its TAPPI, FTIR, SEM, EDX, TGA, WCA, and P content. AP was characterized regarding its pH, conductivity, glucose, furfural, HMF, total sugars and ASL contents. CFL structure was evaluated by FTIR, 1H, 31P and 1H-13C HSQC NMR, TGA and P content and was compared to that of milled wood lignin (MWL). It was observed that MCF and CFL were phosphorylated during the pulping (0.54 and 0.23 % wt., respectively), while AP has shown high sugar levels, low inhibitor content, and some remaining phosphorous. The phosphorylation of MCF and CFL also showed an enhancement of their thermal and thermo-oxidative properties. The results show that a platform of functional materials such as biosorbents, biofuels, flame retardants, and biocomposites can be created through an eco-friendly, simple, fast, and novel biorefinery process.