PhD Defense of Assira Keralta – PhD in Wood and Bio-based Materials Engineering November 17, 2026, from 9:00 a.m. to 12:00 p.m.
You are cordially invited to attend the PhD thesis defense of Assira Keralta, a doctoral candidate in Wood and Bio-based Materials Engineering, which will be held in a hybrid format on Tuesday, November 17, 2026, from 9:00 a.m. to 12:00 p.m.
Online Participation
Those wishing to attend remotely may join the defense via Zoom: https://ulaval.zoom.us/j/68294405517?pwd=QAHaLSbpWOk3yJxNFp5Y8daEk0riak.1
Meeting ID: 682 9440 5517
Passcode: 719766
Information
Tuesday, November 17, 2026, at 9:00 a.m.
Gene-H.-Kruger Building (GHK)
Gilbert-Tardif Room, 2320-2330
Université Laval, Québec, Canada
Examination Committee
Chair: André Desrochers, Faculty of Forestry, Geography and Geomatics, Université Laval
Research Supervisor: Véronic Landry, Faculty of Forestry, Geography and Geomatics, Université Laval
Co-supervisor: Julien Chamberland, Faculty of Agricultural and Food Sciences, Université Laval
Co-supervisor: Marie-Josée Dumont, Faculty of Science and Engineering, Université Laval.
External Examiner: Philippe Gerardin, Laboratoire d’Études et de Recherche sur le Matériau Bois, Université de Lorraine
Examiner: Alain Cloutier, Faculty of Forestry, Geography and Geomatics, Université Laval
Examiner: Ahmed Koubaa, Research Institute on Forests, Université du Québec en Abitibi-Témiscamingue
Examiner: Pierre Blanchet, Faculty of Forestry, Geography and Geomatics, Université Laval
Title: Wood Stabilization in a Circular Economy Context
Abstract:
Wood is a renewable, bio-based material that contributes to carbon storage; however, its susceptibility to moisture and microorganisms can limit its service life under certain conditions. At the same time, the dairy industry generates significant quantities of whey ultrafiltration permeate (UF permeate), a lactose-rich coproduct whose valorization remains limited. This thesis explored a novel approach to transforming this coproduct into a resource for enhancing wood performance within a circular economy framework.
The research focused on the polyesterification of wood, a chemical modification technique in which a polyol and a carboxylic acid react within the wood cell wall. Lactose contained in UF permeate was first investigated as a potential source of hydroxyl groups in combination with various bio-based carboxylic acids.
The reactivity of the formulations and the resulting products were then studied to identify conditions suitable for wood modification. Formulations based on UF permeate combined with either citric acid or malic acid were subsequently applied to various North American wood species. Following impregnation and heat treatment, the modified wood exhibited an anti-swelling efficiency exceeding 40% and a low leaching rate, indicating effective fixation of the compounds within the wood structure.
Formulations based on UF permeate and citric acid also achieved Durability Class 1 (very durable wood) according to EN 350 (2016), compared with Classes 4 and 5 (non-durable wood) observed for untreated wood under the same test conditions. Bending strength was better preserved than with citric acid alone, while surface hardness increased. These findings demonstrate the potential of UF permeate as a renewable source of reagents for wood modification, while also providing a new valorization pathway for a dairy industry coproduct.
This research opens promising avenues for the development of value-added wood products and wood modification processes aligned with circular economy principles. Additional work will nevertheless be required to scale up the process, evaluate new functional properties, and assess its environmental impact.