Defense of Manon Beaufils-Marquet’s thesis – Doctorate in wood and bio-based materials engineering – Thursday, January 30, 2025 at 1pm!
You are cordially invited to attend the PhD thesis Manon Beaufils-Marquet‘s defense, Ph.D. student in wood and bio-based materials engineering, which will take place on Thursday, January 30, 2025, at 1 p.m., in the Gilbert-Tardif room (GHK-2320-2330) of the Gene-H.-Kruger Pavilion.
Connection link for those wishing to attend online: https://ulaval.zoom.us/j/63008334588?pwd=w3s4UltBH55R5mJdwBhYWaHmC3j9vc.1
Jury members:
President: Marie-Hélène Vandersmissen – Faculty of Forestry, Geography and Geomatics, Laval University
Research supervisor: Véronic Landry – Faculty of Forestry, Geography and Geomatics, Laval University
Co-supervisor: Pierre Blanchet – Faculty of Forestry, Geography and Geomatics, Laval University
Non-UL examiner: Flavia Braghiroli – University of Québec in Abitibi-Témiscamingue
UL Examiner: Denis Rodrigue – Faculty of Science and Engineering, Université Laval
External reviewer: Wendy Rodriguez Castellanos – Innofibre
Thesis Title: Development of Alternatives to Spray Foam Insulation in Wood Construction
Abstract: The construction sector accounts for 37% of greenhouse gas emissions and consumes 30% of the world’s energy, mostly derived from fossil fuels. This energy use is split between the construction phase and the operational phase of buildings. Insulating buildings reduces energy consumption during use by optimizing heating efficiency. However, traditional insulation materials like spray polyurethane foam rely on non-renewable fossil resources. Bio-based insulators, such as cellulose wadding or hemp fiber, are already being considered as alternatives, but their properties fall short of matching the thermal conductivity, air, and moisture permeability performance of polyurethane foam.
This research project investigates the substitution of petroleum-based compounds with bioresources in spray polyurethane foam, focusing on cellulose filaments (CFs) produced by Kruger Inc. from northern softwood bleached kraft pulp, which preserves the length of the produced filaments. Cellulose, the most abundant biopolymer in nature, offers significant potential due to its mechanical and thermal properties as well as its availability. Additionally, its hydroxyl groups make it chemically modifiable. The main objective of this project is to develop a sprayable insulation material for wood construction by leveraging this resource, reducing the use of petroleum-based materials while maintaining the performance of current insulators.
The potential of CFs as a filler in polyurethane foam was evaluated, and performance was compared with reference foams prepared in the lab without bio-based components. Foam formulations were adjusted by adding CFs at different percentages, and their properties (viscosity, morphology, water vapor permeability, density, thermal conductivity, and compressive strength) were analyzed. CFs significantly impacted foam properties, particularly cell size and vapor sorption. The studied quantities of filaments (1% w/w CF, 2.5% w/w CF, and 5% w/w CF) allowed compliance with the standard requirements for medium-density spray polyurethane foams. However, results showed minimal improvements in properties without replacing petrochemical components. Excessive CF quantities, i.e., greater than or equal to 5% w/w, deteriorated material properties, limiting integration to less than 5% w/w CF. Using cellulose solely as a filler showed its limitations and proved insufficient to reduce the environmental impact of polyurethane foams. This underscores the need to focus on substituting petroleum-based components in foams.
The chemical modification of CFs to substitute petroleum-based polyol was then investigated. Two etherification methods (using glycerol in one case and glycidol and ethylene carbonate in another) were employed to modify CFs, producing reactive functions accessible via hydroxyl groups to react with the present isocyanate. The resulting bio-based polyols and polyurethane foams were characterized. The same properties as in the first part were studied. Results revealed reduced reactivity of bio-based polyols, affecting cell size and openness, and causing mechanical property deterioration, leading to non-compliance with Canadian standards for polyurethane foams. Nevertheless, promising thermal conductivity results were achieved, remaining competitive with conventional insulation materials (e.g., mineral wool or wood fiber).
Finally, this study evaluated the modification of CFs as a sustainable flame-retardant solution to enhance the environmental performance of polyurethane foam and reduce its toxicity in case of fire. The current commercial petroleum-based flame retardant, tris(1-chloro-2-propyl) phosphate (TCPP), a chlorinated compound, emits toxic fumes during fires. CFs were treated with nitrogen- and phosphorus-based compounds to obtain polyelectrolyte complexes (PECs) and layer-by-layer (LbL) coatings. Morphology, thermogravimetric properties, fire behavior, and water vapor sorption were characterized. Although phosphorus impregnation levels were low compared to the literature, modified CFs demonstrated promising properties comparable to the commercial flame retardant at equivalent phosphorus content, while producing less smoke.