On the Development of Phenol-Formaldehyde Resins Using a New Type of Lignin Extracted from Pine Wood with a Levulinic-Acid Based Solvent

Abstract

Resole resins have many applications, especially for foam production. However, the use of phenol, a key ingredient in resoles, has serious environmental and economic disadvantages. In this work, lignin extracted from pine wood using a “green” solvent, levulinic acid, was used to partially replace the non-sustainable phenol. The physicochemical properties of this novel resin were compared with resins composed of different types of commercial lignins. All resins were optimized to keep their free formaldehyde content below 1 wt%, by carefully adjusting the pH of the mixture. Substitution of phenol with lignin generally increases the viscosity of the resins, which is further increased with the lignin mass fraction. The addition of lignin decreases the kinetics of gelification of the resin. The type and amount of lignin also affect the thermal stability of the resins. It was possible to obtain resins with higher thermal stability than the standard phenol-formaldehyde resins without lignin. This work provides new insights regarding the development of lignin-based resoles as a very promising sustainable alternative to petrol-based resins.

Sub‐Micro Organosolv Lignin as Bio‐Based Epoxy Polymer Component: A Sustainable Curing Agent and Additive

“…The ability of the OBs sub-micro lignin powder to effectively redisperse into a colloidal suspension is of high importance for relevant, water-based industrial and commercial applications of lignin, such as its utilization in the production of phenol-formaldehyde resins, where it replaces a significant part of petroleum-derived phenol. [40,41]…”

“…So far, lignin has been successfully utilized at commercial production level in phenol‐formaldehyde (PF) resins, by substituting a high portion (up to ca. 50 wt %) of the petroleum derived phenol [40,41] . Furthermore, intensive research has initiated for the incorporation of lignin in various polymers, including polyesters like polylactic acid (PLA) and polyethylene terephthalate (PET), polyurethanes, epoxy resins, and rubbers [38,42–45] .…”

“…50 wt %) of the petroleum derived phenol. [40,41] Furthermore, intensive research has initiated for the incorporation of lignin in various polymers, including polyesters like polylactic acid (PLA) and polyethylene terephthalate (PET), polyurethanes, epoxy resins, and rubbers. [38,[42][43][44][45] Depending on the nature, reactive groups and polarity of the pristine polymer, lignin can be also modified in order to enhance the chemical interaction with the (pre)polymer.…”

Performance and characterization of phenol-formaldehyde resin with crude bio-oil by model compound method

“…However, petroleum is a non-renewable natural resource and its continued use is not sustainable. Therefore, in recent decades, many researchers are shifting focus towards renewable materials as a substitute for phenol to produce bio-based PF, such as lignin [ 3 , 4 ], tannin [ 5 ], and cardanol [ 6 ]. Compare with PF, lignin-based PF showed higher adhesion strength [ 4 ], tannin-based PF had less impact on the environment [ 5 ], and cardanol-based PF had better thermal performance [ 6 ].…”

Preparation of High-Toughness Lignin Phenolic Resin Biomaterials Based via Polybutylene Succinate Molecular Intercalation

“…Previous research on lignin phenolic resins has mostly been focused on phenolic foams, adhesives, and other thermosetting resins. The poor processability of the resin limits its applicability [ 6 , 7 , 8 , 9 ].…”