The development of sustainable materials that can replace commercial petrochemical based materials is an incitement for collaboration between academia and industry. Different bio-based product alternatives such as polylactic acid, chitosan, starch and gluten have been considered but cellulosic alternatives such as microfibrillated cellulose (MFC) show unique physical and mechanical properties due to the crystalline nature, high specific surface area and the propensity to form fibrous networks even at low concentrations. Shear-thinning and thixotropic behavior of MFC suspensions also makes them suitable candidates as reinforcing elements or rheology modifiers for/in different industrial applications. MFC has shown large promise in applications such as adhesives and coatings, reinforcing elements in construction materials and packaging materials and finally as additives in printing paper grades. On the other hand, its properties are still not fully understood due to the heterogeneous structure in terms of size and surface charge distribution. In this study, we aimed addressing the challenges in the characterization of heterogeneous biomaterials by fractionating. A commercially available MFC was fractionated into four size components using a recently developed approach in which two physical screening steps were combined with an additional centrifugation step to obtain two coarser and two finer fractions. Each MFC fraction was characterized based on their morphology and surface charge. That data was linked to their viscoelastic properties to reveal the contribution of each size fraction to the rheological properties of the unfractioned water suspension. It was shown that the rheology of the MFC fractions was strongly influenced by the size of the components, and the finest fraction enhanced the gel behavior of the MFC suspension which was reflected in the highest storage modulus. Flow characteristics of each fraction were also analyzed, and all fractions showed non-linear flow behavior.

Influence of microfibrillated cellulose fractions on the rheology of water suspensions: Colloidal interactions and viscoelastic properties

256th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.