Cellulose–Chitosan Biodegradable Materials for Insulating Applications

Abstract

Bio-based lightweight porous materials have attracted attention due to their unique properties and have become an interesting alternative to petroleum-based foams such as expanded polystyrene (EPS) and polyurethane foams. In this work, biodegradable cellulose pulp−chitosan foams were obtained through a low-cost, simple, and scalable method. A full factorial design was carried out to study the effects of three experimental factors (chitosan content, foaming agent concentration, and foaming time) on apparent density and mechanical properties. The prepared foams displayed low apparent densities (0.06−0.12 g/cm 3 ), good mechanical performance (elastic modulus: 0.18−1.20 MPa, compressive strength: 0.02−0.11 MPa), excellent thermal insulation properties (thermal conductivities: 0.03−0.04 W/mK), and high biodegradation rates. The increase of chitosan content improved the water resistance and mechanical strength. Finally, these materials could be suitable for several applications in which thermal insulation, mechanical resistance, and water stability are crucial, including packaging and construction, as an alternative to traditional nonbiodegradable materials.

A Review of Natural Polysaccharides-Based Flocculants Derived from Waste: Application Efficiency, Function Mechanism, and Development Prospects

“…Countries such as India, Poland, Japan, the United States, Norway, and Australia have extracted CS from marine waste and have completed commercial production. CS products have the advantages of nontoxic, antibacterial, strong cell affinity, positive biocompatibility and biodegradability, which is usually considered biologically safe, making them widely respected in water purification engineering. , Unlike most negatively charged plant polysaccharides, CS has amphoteric functional groups in its molecular structure, which enables it to produce an ideal electrostatic adsorption capacity for amphoteric pollutants. , The charge neutralization ability of the flocculant can be further strengthened by modifying the characteristic functional groups of CS. The activated hydroxyl group in the polysaccharide structure is usually used as the reaction site for the modified monomer to attack preferentially, and the grafting reaction is mostly introduced by the deprotonation of the hydroxyl group.…”

“…CS products have the advantages of nontoxic, antibacterial, strong cell affinity, positive biocompatibility and biodegradability, 33 which is usually considered biologically safe, making them widely respected in water purification engineering. 31,34 Unlike most negatively charged plant polysaccharides, CS has amphoteric functional groups in its molecular structure, which enables it to produce an ideal electrostatic adsorption capacity for amphoteric pollutants. 31,35 The charge neutralization ability of the flocculant can be further strengthened by modifying the characteristic functional groups of CS.…”

Chitosan-Functionalized Methacrylate Monoliths for Mixed-Mode Hydrophilic/Electrostatic Interaction Capillary Liquid Chromatography

“…Chitosan is a linear polysaccharide composed of randomly distributed β-(1–4)-linked d -glucosamine (deacetylated unit) and N-acetyl- d -glucosamine (acetylated unit), derived from deacetylation of chitin. − It is a unique stimulus-responsive structure polymer with a pH-dependent net charge and solubility which has been used in sorbent and stationary phase materials. − Among the various merits, chitosan carries many −OH and −NH 2 groups, which promote strong hydrophilic interaction and formation of hydrogen bonds. Furthermore, the chitosan amino group provides a positive charge under acidic conditions, furnishing an electrostatic interaction.…”

Chitin/Chitosan Biocomposite Foams with Chitins from Different Organisms for Sound Absorption

“…Chitin, whether in its pure form or in solution, has seen limited utilization, highlighting an immediate necessity for application on a larger scale. While chitosan and related polysaccharides have been extensively used for biocomposite materials/hybrid materials, − including soft hydrogels, foams, and solid composite materials. , Lightweight insulation materials based on cellulose-chitosan for practical applications are also already known, stressing the importance of mechanical resistance and low density . Significantly less work has been reported about chitin. − In particular chitin-based foams were little explored. − For example, graphene oxide/chitin nanofibrils composite foams to dispose pollutants in aqueous solutions or chitin/chitosan-based nanofibril-reinforced starch foams possessed enhanced flammability and mechanical properties through chitin nanofibrils. , As Achinivu et al showed through the extraction of several different chitin biomass sources that processability, appearance, and mechanical properties highly depend on the chitin biomass source .…”

“…30,31 Lightweight insulation materials based on cellulose-chitosan for practical applications are also already known, stressing the importance of mechanical resistance and low density. 32 Significantly less work has been reported about chitin. 33−36 In particular chitinbased foams were little explored.…”