Polylactic Acid Cellulose Nanocomposite Films Comprised of Wood and Tunicate CNCs Modified with Tannic Acid and Octadecylamine

Abstract

Herein, a one-pot strategy was used to prepare hydrophobic cellulose nanocrystals (CNCs) surface-modified with tannic acid and octadecylamine. By this strategy, CNCs derived from wood (W-CNC) and tunicates (T-CNC) were modified in situ and incorporated into a polylactic acid (PLA) matrix using two methods, without first drying the CNCs. Films of PLA-CNC nanocomposites were prepared both by solution casting and by wet compounding in a thermo-kinetic mixer, followed by melt extrusion. Various properties of these PLA nanocomposites were evaluated herein, along with an assessment of how these properties vary with the type of CNC reinforcement. Cast films with a hybrid mixture of wood and tunicate CNCs displayed improved mechanical properties compared to either wood or tunicate CNCs, but extruded films did not show this hybrid effect. The water vapor permeability of the extruded nanocomposite films with 1% CNCs was reduced by as much as 60% compared to the PLA films. The composite films also showed enhanced biodegradation compared to neat PLA films. These results demonstrate that wet compounded PLA composites produced with wood or tunicate CNCs modified using a one-pot, water-based route have improved barrier and biodegradation properties, indicating a potential for packaging applications without having to dry the CNCs.

Improvement of Poly(lactic acid)-Poly(hydroxy butyrate) Blend Properties for Use in Food Packaging: Processing, Structure Relationships

“…To avoid aggregation, nanocrystals generally undergo hydrophobic surface modifications before nanocomposite preparations [ 24 , 29 , 30 ]. Unfortunately, these hydrophobic surface modifications frequently have significant economic and environmental drawbacks, which limit their industrial potential [ 31 ]. Previously, a scalable liquid-assisted extrusion approach was proposed to improve the dispersion of nanocrystals and, as a consequence, improve the final properties of the final formulations [ 32 , 33 , 34 ].…”

Accelerating the Biodegradation of Poly(lactic acid) through the Inclusion of Plant Fibers: A Review of Recent Advances

“…A recent study investigated the anaerobic digestion of PLAcellulose nanocrystal biocomposites under mesophilic conditions using a modified version of the ISO 14853 standard. 130 In the study, the authors prepared two composites incorporating either wood cellulose nanocrystals or tunicate cellulose nanocrystals, which are derived from the tunics or coats of some marine creatures and typically have a very high cellulose content. Biocomposite films were mixed in a reactor with inoculum and sludge from a pollution control plant, lactose, and starch.…”

Manipulation of Crystallization Nucleation and Mechanical Properties of PBAT Films by Octadecylamine-Cellulose

“…Octadecylamine (ODA) is a low-cost chemical reagent used to hydrophobically modify cellulose and improve its wettability in organic solvents. This is achieved through a simple, free coupling-agent amidation reaction, in a mixture of ethanol and water, making the production process environmentally friendly, sustainable, and safe, 17,18 and also further enhanced polymer's mechanical behavior. 19 Mechanical and barrier properties and heat resistance of material is influenced by cystallization.…”