200
stability than those cured with DETA. However, the thermal stability of all ligninbased samples was comparable to the thermal properties of petroleum-based epoxy
resins. In addition, the char yield at 800 °C for the DKL-DDM formulation (38%)
was much higher than conventional bisphenol A-based epoxy resins. This suggests
that the DKL-DDM formulation could be a promising substitute for petroleumbased epoxy resins.
Ferdosian et al. (2016a) continued studying bisphenol A-based epoxy resins containing DOL and DKL as composites. These results showed that maximum degradation temperature (T max ) was almost stable between 397 and 404 °C, and this was
very similar to bisphenol A-epoxy resin (405 °C). In addition, the oxygen limiting
index (LOI) of all lignin-based epoxy composites was higher than that of conventional bisphenol A-based epoxy resin, and they also showed greater thermal resistance even when compared to the diglycidylether bisphenol A (DGEBA)-cured
epoxy resin. In particular, the 100% DKL-DDM formulation was the most thermally resistant system, and 75% DKL-DDM, 100% DKL-DDM, and 100% DOLDDM formulations can be classified as self-extinguishing materials.
Ferdosian et al. (2016b) also studied the synthesis of biobased epoxy resin using
DHL obtained from low pressure de-polymerization. They found that Mw of DHL
varied from 2100 g mol to 5530 g/mol after the epoxidation reaction, and the thermal degradation activation energy of the DHL-epoxy-DDM system was greater
than the DGEBA-DDM system during the curing process, which can be associated
with low molecular mobility of the DHL-epoxy resin and the highest Mw and viscosity. In addition, mechanical properties such as tensile strength, flexural strength,
Young’s modulus and flexural modulus decreased significantly when the percentage
of lignin-based epoxy resin was higher. This suggests the potential of using ligninrich wastes and by-products to obtain greater added-value biobased materials.
The study of epoxy resins cured with Ligno Boost™ softwood kraft lignin (KL)
isolated from the original black liquor was reported by Jablonskis et al. (2018). For
this, lignin-based epoxy resins were obtained in two ways: extraction with acetone
of glycidylated lignin and glycidylation of the acetone-soluble lignin fraction. They
found that the addition of 2–10% of commercial bisphenol A-based Araldite LY1564
decreased the T max and increased the following mechanical parameters: stress at
break, Young’s modulus, and strain at break, and also a tendency to increase the
Young’s modulus of lignin-containing cured epoxy resins was observed. The lignin
incorporated into the cured commercial epoxy resin matrix acts as a charcoal forming promoter in the high temperature treatment.
Sasaki et al. (2013) extracted lignin from bamboo moso using the steam explosion methodology followed by water and methanol extractions for the synthesis of
epoxy resins of lignin cured with DGEBA or 1-(2-cyanoethyl)-2-ethyl-4methylimidazole (2E4MZ-CN). These authors determined that thermal decomposition properties of the lignin-based epoxy resins exceeded the dip-solder resistance
(250–280 °C), and the mechanical properties indicated the potential usefulness of
manufactured resins.
Asada et al. (2015a) studied the synthesis of the epoxy resin containing lignin
extracted from bamboo moso (Phyllostachys pubescens), cedar (Cryptomeria
C. Asada et al.
stability than those cured with DETA. However, the thermal stability of all ligninbased samples was comparable to the thermal properties of petroleum-based epoxy
resins. In addition, the char yield at 800 °C for the DKL-DDM formulation (38%)
was much higher than conventional bisphenol A-based epoxy resins. This suggests
that the DKL-DDM formulation could be a promising substitute for petroleumbased epoxy resins.
Ferdosian et al. (2016a) continued studying bisphenol A-based epoxy resins containing DOL and DKL as composites. These results showed that maximum degradation temperature (T max ) was almost stable between 397 and 404 °C, and this was
very similar to bisphenol A-epoxy resin (405 °C). In addition, the oxygen limiting
index (LOI) of all lignin-based epoxy composites was higher than that of conventional bisphenol A-based epoxy resin, and they also showed greater thermal resistance even when compared to the diglycidylether bisphenol A (DGEBA)-cured
epoxy resin. In particular, the 100% DKL-DDM formulation was the most thermally resistant system, and 75% DKL-DDM, 100% DKL-DDM, and 100% DOLDDM formulations can be classified as self-extinguishing materials.
Ferdosian et al. (2016b) also studied the synthesis of biobased epoxy resin using
DHL obtained from low pressure de-polymerization. They found that Mw of DHL
varied from 2100 g mol to 5530 g/mol after the epoxidation reaction, and the thermal degradation activation energy of the DHL-epoxy-DDM system was greater
than the DGEBA-DDM system during the curing process, which can be associated
with low molecular mobility of the DHL-epoxy resin and the highest Mw and viscosity. In addition, mechanical properties such as tensile strength, flexural strength,
Young’s modulus and flexural modulus decreased significantly when the percentage
of lignin-based epoxy resin was higher. This suggests the potential of using ligninrich wastes and by-products to obtain greater added-value biobased materials.
The study of epoxy resins cured with Ligno Boost™ softwood kraft lignin (KL)
isolated from the original black liquor was reported by Jablonskis et al. (2018). For
this, lignin-based epoxy resins were obtained in two ways: extraction with acetone
of glycidylated lignin and glycidylation of the acetone-soluble lignin fraction. They
found that the addition of 2–10% of commercial bisphenol A-based Araldite LY1564
decreased the T max and increased the following mechanical parameters: stress at
break, Young’s modulus, and strain at break, and also a tendency to increase the
Young’s modulus of lignin-containing cured epoxy resins was observed. The lignin
incorporated into the cured commercial epoxy resin matrix acts as a charcoal forming promoter in the high temperature treatment.
Sasaki et al. (2013) extracted lignin from bamboo moso using the steam explosion methodology followed by water and methanol extractions for the synthesis of
epoxy resins of lignin cured with DGEBA or 1-(2-cyanoethyl)-2-ethyl-4methylimidazole (2E4MZ-CN). These authors determined that thermal decomposition properties of the lignin-based epoxy resins exceeded the dip-solder resistance
(250–280 °C), and the mechanical properties indicated the potential usefulness of
manufactured resins.
Asada et al. (2015a) studied the synthesis of the epoxy resin containing lignin
extracted from bamboo moso (Phyllostachys pubescens), cedar (Cryptomeria
C. Asada et al.