Développement d'une nouvelle génération de composites biosourcé avancés à base de coproduits issus de la production d'éthanol cellulosique

Following the COP21 conference in Paris, Canada and especially Quebec have made ambitious commitments to reduce their greenhouse gas (GHG) emissions 37.5% below 1990's level by 2030. To achieve this goal, the development of biobased materials may represent an interesting solution since it would allow sequestering carbon, while replacing compounds originating from fossil fuels. The proposed project aims at developing a fully biobased composite material from a coproduct of the cellulosic ethanol production process developed at the Biomass Technology Laboratory (BTL). The coproducts that will be used will be biobased as well and the latter will be combined with lignin and microcrystalline cellulose. Numerous studies have demonstrated the ability of the lignin to form a three-dimensional crosslinked network, which possess good mechanical properties and durability in the presence of a suitable polymerization intermediate. Indeed, the interest of lignin for the production of glues or thermosetting composites has been demonstrated repetitively in open literature [1,2]. In addition, microcrystalline cellulose also has the property of reinforcing composites. Professor Lavoie's team previously showed that microcrystalline cellulose could significantly improve the mechanical properties of thermoplastic polymers. Cellulose is also known to have better compatibility with thermosetting polymers over thermoplastic polymers and therefore does not require a compatibilization agent. The composition of coproducts having carboxylic acid functions is therefore suitable to produce a composite having good mechanical properties. Lignin makes it possible to form a thermosetting resin acting as the matrix of the composite while microcrystalline cellulose plays the role of fibrous reinforcement. In order to allow the polymerization of lignin, the polymerization agent used will have acid functions as well as being biobased and available at industrial scale. Various studies indicate that carboxylic acid functions are functional as polymerization agent with lignocellulosic biomass, especially for the production of particle board. In this project, the composite production parameters such as polymerization agent/ lignin ratio, temperature, pressure, time and shaping pressure will be optimized to maximize mechanical properties. The resulting composite will be characterized to determine the most suitable applications. Different shaping processes will also be tested such as molding. The applications for this composite are potentially large, for example it could be used in the field of construction and in the motor industry.