From Waste to Valuable Resource: Lignin as a Sustainable Anti-Corrosion Coating

Abstract

In this study, a waste of biorefinery—lignin—is investigated as an anticorrosion coating on stainless steel. Corrosion behavior of two lignin types (hardwood beech and softwood spruce) was studied by electrochemical measurements (linear sweep voltammetry, open circuit potential, potentiostatic polarization, cyclic potentiodynamic polarization, and electrochemical impedance measurements) during exposure to simulated body fluid (SBF) or phosphate buffer (PBS). Results from linear sweep voltammetry of lignin-coated samples, in particular, demonstrated a reduction in corrosion current density between 1 and 3 orders of magnitude cf. blank stainless steel. Furthermore, results from cross cut adhesion tests on lignin-coated samples demonstrated that the best possible adhesion (grade 0) of ISO 2409 standard was achieved for the investigated novel coatings. Such findings suggest that lignin materials could transform the field of organic coatings towards more sustainable alternatives by replacing non-renewable polymer coatings.

Spherical lignin particles: a review on their sustainability and applications

“…(ii) reproducibility (iii) easy application and cost-effectiveness (iv) tailored surface morphology and (v) environmental friendliness. 131 Spherical lignin particles seem beneficial regarding many of the above requirements, since lignin can provide surfaces with UV-protection, 132 corrosion inhibition, 133,134 antimicrobial activity, 129,130 removable/self-healable, 135 as well as fire-retardant 136 and drug release properties, 137 making lignin attractive for functional coating purposes.…”

Construction of ecofriendly anticorrosive composite film ZnAl‐LDH by modification of lignin on AA 7075 surface

“…[ 46,48 ] The peak at 856 cm −1 rose from C–H out‐of‐plane vibration. [ 40 ] The peaks originated from carboxyl and carbonyl stretching can be hardly observed, suggesting that phenolic units were much more abundant than the carboxyl groups in the lignin. This result demonstrates that the lignin used in our work possessed excellent metal complexing property, because the phenolic sites had a higher affinity for metal ions than the carboxylic sites according to the reported literature.…”

“…[ 29,37–39 ] Some researchers reported that phenolic–OH groups in lignin were more likely to form metal–lignin compounds than carboxylic groups due to the higher affinity of phenolic sites than the carboxylic sites. [ 38,40 ] As mentioned above, defects always appear in LDH films on alloy surface, and lignin is proposed in this study to form a complex with the metal ions in the defects and inhibit the further dissolution of metal substrate in the defect. Thus, the limitations of LDH film with defects on alloy surface are aimed to be addressed in this way; meanwhile, the value of lignin can be improved and its application potential can be further exploited as well.…”

Nontargeted Analysis Strategy for the Identification of Phenolic Compounds in Complex Technical Lignin Samples

“…[6] By synthesizing two poly(ether amide)s from lignin-derived precursors, Saenz and Scott showed that lignin-based polymers are achievable. [7] Other recent studies have shown that lignin could also be used to produce UV-curable coatings, [8] nanoparticles, [9] elastomers, [10] anticorrosion coating for metal surfaces, [11] and carbon fibers. [12] Chaleawlert-umpon et al and Mukhopadhyaye tal.…”