top of page

Arman Dastpak: Performance of Lignin as a Sustainable Anticorrosion Coating

Fri, 13 May

|

Espoo

This thesis investigates the performance of technical lignin—a primary waste from biomass processing industries—as an organic binder in anticorrosion coatings, with a focus on the industrial applicability of these materials and associated deposition techniques.

There is no need to register. Please join the defense through the link provided below.
See other events
Arman Dastpak: Performance of Lignin as a Sustainable Anticorrosion Coating
Arman Dastpak: Performance of Lignin as a Sustainable Anticorrosion Coating

Time & Location

13 May 2022, 12:00 – 15:00

Espoo, Lecture hall Aluminium, Vuorimiehentie 2, 02150 Espoo, Finland

About the Event

Abstract:

Synthetic polymers play a pivotal role in many industrial applications that includes their utilization as barrier coatings for corrosion protection of metal surfaces. However, use of such non-renewable coatings results in environmental pollution both during production and use. As such, there is a global effort to find/produce more sustainable metal coatings from renewable resources including biomass-based polymers. Consequently, this thesis investigates the performance of technical lignin—a primary waste from biomass processing industries—as an organic binder in anticorrosion coatings, with a focus on the industrial applicability of these materials and associated deposition techniques.

Electrochemical properties of stainless steel spin-coated with two different organosolv lignin (dissolved in 1,4-Dioxane) were investigated. Results showed that the coatings enhanced the resistance of surfaces against corrosion with a lignin source-dependent variation of the barrier properties. In order to address the limited lignin solubility in many organic solvents, the screening of a series of industrially-applicable organic solvents was undertaken. Findings indicated that two solvents—diethylene glycol monobutyl ether (DEGBE) and propylene glycol monomethyl ether (PGME)—act as strong solvents for a kraft and an organosolv lignin, and that DEGBE also has a plasticizing effect on lignin. However, electrochemical analysis of lignin-coated steel prepared from PGME following prolonged immersion (24 hours) in 5 wt.% NaCl, showed that these coatings offer limited protection. Furthermore, cracking of lignin-PGME coatings was observed, which was found to be mitigated by addition of triethyl citrate (TEC) as a plasticizer.

An alternative and more environmentally benign route for the preparation of lignin-based coatings was further achieved by the preparation of aqueous dispersions of colloidal lignin particles (CLPs) using DEGBE as the starting solvent in a solvent-exchange procedure. Consequently, it was possible to prepare combined lignin-cellulose composite coatings using electrophoretic deposition (EPD) from aqueous dispersions at low deposition potentials, and resulted in coatings with enhanced durability during long term immersion (15 days) in 3.5 wt.% NaCl electrolyte. An important outcome of this process was the coalescense of CLPs during drying—as a result of the DEGBE—that enabled the formation of compact coatings. Such techniques and coalescing characteristics could be exploited in the preparation of water-borne lignin layers with enhanced corrosion protection capabilities as part of a future fully sustainable coating formulation.

Follow the remote defencehttps://aalto.zoom.us/j/63652927222

Opponents: Professor Iris De Graeve, Vrije Universiteit Brussel, Belgium

Supervisor: Professor Mari Lundström, Aalto University, Department of Chemical and Metallurgical Engineering

Link to electronic thesis: Performance of Lignin as a Sustainable Anticorrosion Coating

Share This Event

bottom of page