Tuning Properties of High-consistency Enzymatically Fibrillated Cellulose (HefCel) for Various Applications

Description

Cellulose nanomaterials are promising renewable, bio-based and biodegradable materials, which have been explored for numerous applications such as, packaging, biotechnology, drug delivery, 3D printing, rheology modification, electronics, etc. These exciting applications have led to development of various production methods for nanocellulose materials worldwide, some of which are already commercial. However, challenges related to production costs still prevail and often the resulting material is at low consistency, typically between 1%–5%, which limits logistics and applications in areas demanding low water amount during processing. To overcome these problems, a high-consistency enzymatic fibrillation (HefCel) technology was developed at VTT, allowing nanocellulose production at 10%–25% consistency with significantly lower energy consumption compared to other manufacturing methods. Additionally, this technology offers the ability to tune the properties of fibrillated material according to the end-use. This work explores the effect of raw materials and enzyme dosage on the fibrillated cellulose properties relevant for papermaking, film forming and coating applications.
Enzymatically fibrillated cellulose was produced from three different bleached chemical pulps viz. never-dried softwood, once-dried softwood, and once-dried hardwood pulp. Three different enzyme dosage levels were used to produce nine different HefCel grades. All HefCel grades were characterized to ascertain their carbohydrate composition, fiber morphology, water retention, rheological behavior and film-forming properties. Morphology of the HefCel grades was correlated with their corresponding dewatering and rheological behavior (both in terms of viscosity and viscoelasticity) in order to develop a structure-property relationship map. For demonstrating the performance of these grades in a typical application, films were produced and characterized for their mechanical and barrier properties.
HefCel technology was found quite flexible in tuning the final properties of the fibrillated material. Irrespective of raw material choice, changing enzyme dosage level allowed significant modification of fiber morphology (which governs dewatering and rheology), while keeping the carbohydrate composition intact.

Period	15 Jun 2021 → 16 Jun 2021
Event title	TAPPI Nano 2021
Event type	Conference
Degree of Recognition	International