Green Phenolic Resins from Oil Palm Empty Fruit Bunch (EFB) Phenolated Lignin and Bio-Oil as Phenol Substitutes for Bonding Plywood

• Published in: Polymers
• Main Author: Lim K.Y.; Yasim-Anuar T.A.T.; Sharip N.S.; Ujang F.A.; Husin H.; Ariffin H.; Md Tahir P.; Li X.; Lee S.H.; Yusof M.T.
• Format: Article
• Language: English
• Published: MDPI 2023
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85149778640&doi=10.3390%2fpolym15051258&partnerID=40&md5=5cd607e9264eefe78d779dc3cf7cd47f

Lignin is a natural biopolymer with a complex three-dimensional network and it is rich in phenol, making it a good candidate for the production of bio-based polyphenol material. This study attempts to characterize the properties of green phenol-formaldehyde (PF) resins produced through phenol substitution by the phenolated lignin (PL) and bio-oil (BO), extracted from oil palm empty fruit bunch black liquor. Mixtures of PF with varied substitution rates of PL and BO were prepared by heating a mixture of phenol–phenol substitute with 30 wt.% NaOH and 80% formaldehyde solution at 94 °C for 15 min. After that, the temperature was reduced to 80 °C before the remaining 20% formaldehyde solution was added. The reaction was carried out by heating the mixture to 94 °C once more, holding it for 25 min, and then rapidly lowering the temperature to 60 °C, to produce the PL−PF or BO−PF resins. The modified resins were then tested for pH, viscosity, solid content, FTIR, and TGA. Results revealed that the substitution of 5% PL into PF resins is enough to improve its physical properties. The PL−PF resin production process was also deemed environmentally beneficial, as it met 7 of the 8 Green Chemistry Principle evaluation criteria. © 2023 by the authors.