Nanocellulose Hybrid Lignin Complex Reinforces Cellulose to Form a Strong, Water-Stable Lignin–Cellulose Composite Usable as a Plastic Replacement

Abstract

The significant challenges in the use of cellulose as a replacement for plastic are its mechanical properties’ degradation and uncontrolled deformation during the rewetting process. Herein, inspired by the reinforcement of cellulose by lignin in natural plant tissue, a strong and water-stable lignin–cellulose composite (LCC) was developed. A nanocellulose hybrid lignin complex (CHLC) created from bagasse residue after enzymatic hydrolysis was added into a pulp of bleached fibre extracted from pine to produce a lignin–cellulose sheet. The lignin as a water-stable reinforcing matrix, via the hydrogen bonding of the nanocellulose in the CHLC with the fibre was efficiently introduced onto the fibres and the fibre network voids. Compared with a typical lignin-free cellulose sheet, the dry strength and wet strength of the LCC were 218% and 2233% higher, respectively. The developed LCC is an eco-friendly and biodegradable alternative to plastic.

Beyond waste: Transforming wheat straw into oxygen and UV‐resistant cellulose films

“…This shows that the addition of lignin can improve the wet strength of the film to a certain extent. There are three reasons: The hydroxyl group in lignin forms intermolecular hydrogen bond with the hydroxyl group of cellulose, which reduces the destruction of hydrogen bond of cellulose by water molecule; lignin contains some hydrophobic bonds, but also effective resistance to water molecules on the film damage; the hydrophobic lignin can fill the blank of the fiber network, and form a network between lignin to strengthen the fiber network, which limits the water absorption and expansion of the fiber, and improves the tensile strength of the film 36 . In the analysis of significant variance, we can also see that the addition of lignin to improve the tensile strength of the film is significant ( p < 0.05).…”

Lignin-enhanced wet strength of cellulose-based materials: a sustainable approach

“…Bai et al enzymatically hydrolyzed bagasse to produce lignin from bagasse residues. 112 They added different mass proportions of lignin to the bleached fiber pulp extracted from pine trees and then hot-pressed these pulps at 150 °C and 4 MPa for 30 min to produce lignin-cellulose flakes. The introduction of enzymatic lignin significantly improved the tensile strength and water stability of cellulose.…”

The Formation of All-Silk Composites and Time–Temperature Superposition

“…Raw fibre sheets of these biomaterials have inherent flaws compared to composites. Existing voids act as water channels to allow degradation by wetting, and hydrogen bonds can be broken by water molecules, which allows solvation and plasticisation [ 68 ]. This and other issues can be overcome by their inclusion in composites, which can improve material properties.…”