Assessing the suitability of an enzymatic pretreatment for enhancing refining effectiveness and surface modification during the production of nanofibrillated celluloses

近年来，对加拿大纸浆纤维的需求下降，导致对传统纸浆资源衍生的新的高价值产品进行广泛的研究和开发。这些产品包括工业纤维素，如纳米晶和纳米原纤化纤维素。这些材料在许多非传统市场中具有高价值的应用，包括作为纤维塑料复合材料中的增强材料，作为涂料、化妆品和工业流体中的流变改性剂，以及作为混凝土中的强度增强剂。目前对这些材料的成本效益生产的挑战包括精炼的高能量要求、精炼后材料的异质性以及与将这些材料并入最终产品相关的困难（例如当将纤维素并入塑料复合材料时的表面改性和复合挑战）。先前降低精炼能量和产品异质性的工作成功地在精炼前的预处理步骤中使用了许多经典纤维素酶。然而，自从这项工作进行以来，已经鉴定出几种新的酶家族，它们特异性地促进纤维素纤维的原纤化和“无定形”。在这里提出的项目中，将评估这些新酶家族提高机械精炼过程效率和有效性的能力。此外，将使用许多定制的表面改性聚合物来评估这些酶增强纤维素对表面改性的敏感性的能力。最后，将精制产品混配成塑料，以评估原纤化纤维素的性质如何影响最终复合材料的机械性能。总的来说，该项目旨在提高高科技应用中高度精制纤维素材料的效率，质量和适用性。具有成本效益地生产这些新的原纤化纤维素材料的能力将使加拿大纸浆和造纸部门能够使其产品流多样化，并进入新的、非传统的、高价值的市场，为振兴这一关键工业部门提供一条有希望的道路。

In recent years, falling demand for Canadian pulp fibres has led to extensive research and development into new high-value products derived from traditional pulp resources. These products include technical celluloses such as nanocrystalline and nanofibrilated cellulose. These materials have high-value applications in a number of non-traditional markets, including as reinforcing material in fibre-plastic composites, as rheology modifiers in paints, cosmetics, and industrial fluids, and as strength reinforcing agents in concrete. Current challenges to the cost-effective production of these materials include the high energy requirements of refining, the heterogeneity of the material after refining, and difficulties associated with incorporating these materials into the final products (such as surface modification and compounding challenges when incorporating the cellulose into plastic composites). Previous work into reducing refining energy and product heterogeneity successfully used a number of classical cellulase enzymes in a pretreatment step prior to refining. However in the years since this work was performed several new enzyme families have been identified which specifically promote fibrillation and 'amorphogenesis' of cellulosic fibers. In the project proposed here, these new enzyme families will be assessed for their ability to enhance the efficiency and effectiveness of the mechanical refining process. Additionally, the ability of these enzymes to enhance the susceptibility of the cellulose to surface modification will be assessed, using a number of tailor-made surface modification polymers. Finally, the refined products will be compounded into plastics to assess how the properties of the fibrillated celluloses affect the mechanical properties of the final composite materials. Overall, this project aims to improve the efficiency, quality and suitability of highly refined cellulosic materials for high-tech applications. The ability to cost-effectively produce these new fibrillated cellulosic materials will enable the Canadian pulp and paper sector to diversify its product streams and enter into new, non-traditional, high-value markets, providing a promising path to revitalizing this key industrial sector.