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Chitosan, Chitin, and Cellulose Nanofiber Biomaterials

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A special issue of Polymers (ISSN 2073-4360). This special issue belongs to the section "Biomacromolecules, Biobased and Biodegradable Polymers".

Deadline for manuscript submissions: closed (31 May 2022) | Viewed by 35172

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Prof. Dr. Anayancy Osorio-Madrazo

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1. Institute of Microsystems Engineering IMTEK, University of Freiburg, 79110 Freiburg im Breisgau, Germany
2. Freiburg Materials Research Center FMF, University of Freiburg, 79104 Freiburg im Breisgau, Germany
3. Freiburg Center for Interactive Materials and Bioinspired Technologies FIT, University of Freiburg, 79110 Freiburg im Breisgau, Germany
Interests: polymers; polymer chemistry; polymer physical chemistry; biomaterials; hydrogels; composites; scaffolds; spun fibers; nanofibers; additive manufacturing; tissue engineering; 3D bioprinting; biocompatible materials; biopolymers; polysaccharides; polyelectrolyte complex nanoparticles; colloids; biodegradable materials; organ-on-a-chip; drug controlled release; mechanical properties; functional polymer materials; microparticles; beads; X-ray scattering techniques, microstructure characterization; knitted fabrics; membranes; coatings; biomedical applications; biosensors
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Dear Colleagues,

There is increasing interest in using natural polymers and fiber-filled composites to achieve the development of functional biomaterials for the most varied applications. Commonly used biopolymers are the polysaccharides chitosan, chitin, cellulose, and their derivatives. Chitosan is a copolymer of β(1®4)-linked D-glucosamine and N-acetyl D-glucosamine, mainly produced by deacetylation of chitin – the second most abundant polysaccharide worldwide, whose major source is the crustacean cuticle. The degree of acetylation and molecular weight are the most important copolymer parameters, defining the physico-chemistry and properties of the chitinous compound. Chitosan structurally belongs to the glycosaminoglycan family, which bioactivity has been revealed in tissue engineering studies centered on skin, bone, cartilage, and more recently intervertebral disc. Chitinous biomaterial biocompatibility together with bioactivity documents its great potential for biomedical applications. Fundamental research relating chitosan/chitin physico-chemistry with biological properties is only addressed by a relatively minor number of studies.

Many biological materials consist of composites reinforced by fibers. Native cellulose presents a microfibrillated structure consisting of crystalline (40-80%) and amorphous regions. The microfibrils present very high aspect ratio. They are very large in length with diameters of few decades of nanometers and width of elementary fibrils of around 5 nm. Cellulose nanofibers (CNF) unique mechanical properties and renewability increasingly motivate their use as filler in nanocomposites. There is the perspective of efficient production and valorization of this excellent nanoreinforcement in advantage to other natural and synthetic fibers. As a nanomaterial, the question on CNF toxicity and environmental impact has been addressed. Good CNF biocompatibility has been also reported. The chitosan bioactivity and the outstanding CNF mechanical properties, with non-toxic properties and low environmental risk promise safe biomedical applications.

This special issue is oriented to all types of biomaterials (biological materials, bio-based materials and biomaterials for biomedical applications) presenting chitosan, chitin, and/or cellulose nanofibers. Special attention will be given to researches: (i) getting insight into the microstructure-properties relationship in both biological and engineering materials; (ii) covering the understanding of biopolymer physical-chemistry behavior to achieve biomaterial appropriate physical forms and properties for target applications and functionalities, by interrelating processing-microstructure-function-biological response. It will be emphasized in biomedical applications, but the special issue will not be limited to this field.

Prof. Dr. Anayancy Osorio-Madrazo
Guest Editor

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Keywords

chitosan
chitin
cellulose nanofibers
composites
biomaterials
drug delivery
tissue engineering
3D (bio)printing
micro-/nanoparticles
hydrogels
fibers
scaffolds

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Chitosan and its Derivatives: Structure, Properties, and Applications in Polymers (50 articles)

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Research

15 pages, 4018 KiB

Open AccessArticle

Evaluating Non-Conventional Chitosan Sources for Controlled Release of Risperidone

by Sara Garcinuño, Inmaculada Aranaz, Concepción Civera, Concepción Arias and Niuris Acosta

Polymers 2022, 14(7), 1355; https://doi.org/10.3390/polym14071355 - 26 Mar 2022

Cited by 6 | Viewed by 1866

Abstract

In this work, two chitosan samples from cuttlebone and squid pen are produced and characterized. We studied the formation of thermoresponsive hydrogels with β-glycerol phosphate and found proper formulations that form the hydrogels at 37 °C. Gel formation depended on the chitosan source being possible to produce the thermoresponsive hydrogels at chitosan concentration of 1% with cuttlebone chitosan but 1.5% was needed for squid pen. For the first time, these non-commercial chitosan sources have been used in combination with β-glycerol phosphate to prepare risperidone formulations for controlled drug delivery. Three types of formulations for risperidone-controlled release have been developed, in-situ gelling formulations, hydrogels and xerogels. The release profiles show that in-situ gelling formulations and particularly hydrogels allow an extended control release of risperidone while xerogels are not appropriate formulations for this end since risperidone was completely released in 48 h. Full article

(This article belongs to the Special Issue Chitosan, Chitin, and Cellulose Nanofiber Biomaterials)

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15 pages, 4584 KiB

Open AccessArticle

Biological Behavior of Xenogenic Scaffolds in Alcohol-Induced Rats: Histomorphometric and Picrosirius Red Staining Analysis

by Dayane Maria Braz Nogueira, André Luiz de Faria Figadoli, Patrícia Lopes Alcantara, Karina Torres Pomini, Iris Jasmin Santos German, Carlos Henrique Bertoni Reis, Geraldo Marco Rosa Júnior, Marcelie Priscila de Oliveira Rosso, Paulo Sérgio da Silva Santos, Mariana Schutzer Ragghianti Zangrando, Eliana de Souza Bastos Mazuqueli Pereira, Miguel Ângelo de Marchi, Beatriz Flavia de Moraes Trazzi, Jéssica de Oliveira Rossi, Samira Salmeron, Cláudio Maldonado Pastori, Daniela Vieira Buchaim and Rogerio Leone Buchaim

Polymers 2022, 14(3), 584; https://doi.org/10.3390/polym14030584 - 31 Jan 2022

Cited by 9 | Viewed by 2745

Abstract

In this experimental protocol, the objective was to evaluate the biological behavior of two xenogenic scaffolds in alcohol-induced rats through histomorphometric and Picrosirius Red staining analysis of non-critical defects in the tibia of rats submitted or not to alcohol ingestion at 25% v/v. Eighty male rats were randomly divided into four groups (n = 20 each): CG/B (water diet + Bio-Oss^® graft, Geistlich Pharma AG, Wolhusen, Switzerland), CG/O (water diet + OrthoGen^® graft, Baumer, Mogi Mirim, Brazil), AG/B (25% v/v alcohol diet + Bio-Oss^® graft), and AG/O (25% v/v alcohol diet + OrthoGen^® graft). After 90 days of liquid diet, the rats were surgically obtained, with a defect in the tibia proximal epiphysis; filled in according to their respective groups; and euthanized at 10, 20, 40 and 60 days. In two initial periods (10 and 20 days), all groups presented biomaterial particles surrounded by disorganized collagen fibrils. Alcoholic animals (AG/B and AG/O) presented, in the cortical and medullary regions, a reactive tissue with inflammatory infiltrate. In 60 days, in the superficial area of the surgical cavities, particles of biomaterials were observed in all groups, with new compact bone tissue around them, without complete closure of the lesion, except in non-alcoholic animals treated with Bio-Oss^® xenograft (CG/B), where the new cortical interconnected the edges of the defect. Birefringence transition was observed in the histochemical analysis of collagen fibers by Picrosirius Red, in which all groups in periods of 10 and 20 days showed red-orange birefringence, and from 40 days onwards greenish-yellow birefringence, which demonstrates the characteristic transition from the formation of thin and disorganized collagen fibers initially to more organized and thicker later. In histomorphometric analysis, at 60 days, CG/B had the highest volume density of new bone (32.9 ± 1.15) and AG/O the lowest volume density of new bone (15.32 ± 1.71). It can be concluded that the bone neoformation occurred in the defects that received the two biomaterials, in all periods, but the Bio-Oss^® was superior in the results, with its groups CG/B and AG/B displaying greater bone formation (32.9 ± 1.15 and 22.74 ± 1.15, respectively) compared to the OrthoGen^® CG/O and AG/O groups (20.66 ± 2.12 and 15.32 ± 1.71, respectively), and that the alcoholic diet interfered negatively in the repair process and in the percentage of new bone formed. Full article

(This article belongs to the Special Issue Chitosan, Chitin, and Cellulose Nanofiber Biomaterials)

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16 pages, 4762 KiB

Open AccessArticle

In Vivo Study of Nasal Bone Reconstruction with Collagen, Elastin and Chitosan Membranes in Abstainer and Alcoholic Rats

by Fabricio Egidio Pandini, Fabíola Mayumi Miyauchi Kubo, Ana Maria de Guzzi Plepis, Virginia da Conceição Amaro Martins, Marcelo Rodrigues da Cunha, Vinicius Rodrigues Silva, Vinicius Barroso Hirota, Everton Lopes, Marcos Antonio Menezes, André Antonio Pelegrine, Tiago Negrão de Andrade, Amilton Iatecola, Bruna da Cruz Britto, Victor Augusto Ramos Fernandes, Luis Felipe Orsi Gameiro, Ronny Rodrigues Correia, Marcelo Lucchesi Teixeira, Getúlio Duarte Júnior, Carlos Henrique Bertoni Reis, Eliana de Souza Bastos Mazuqueli Pereira, Daniela Vieira Buchaim, Karina Torres Pomini, Daniel de Bortoli Teixeira, Rogerio Leone Buchaim and Edmir Américo Lourenço Show full author list Hide full author list

Polymers 2022, 14(1), 188; https://doi.org/10.3390/polym14010188 - 04 Jan 2022

Cited by 12 | Viewed by 2374

Abstract

The aim of the present study was to evaluate the use of collagen, elastin, or chitosan biomaterial for bone reconstruction in rats submitted or not to experimental alcoholism. Wistar male rats were divided into eight groups, submitted to chronic alcohol ingestion (G5 to G8) or not (G1 to G4). Nasal bone defects were filled with clot in animals of G1 and G5 and with collagen, elastin, and chitosan grafts in G2/G6, G3/G7, and G4/G8, respectively. Six weeks after, all specimens underwent radiographic, tomographic, and microscopic evaluations. Bone mineral density was lower in the defect area in alcoholic animals compared to the abstainer animals. Bone neoformation was greater in the abstainer groups receiving the elastin membrane and in abstainer and alcoholic rats receiving the chitosan membrane (15.78 ± 1.19, 27.81 ± 0.91, 47.29 ± 0.97, 42.69 ± 1.52, 13.81 ± 1.60, 18.59 ± 1.37, 16.54 ± 0.89, and 37.06 ± 1.17 in G1 to G8, respectively). In conclusion, osteogenesis and bone density were more expressive after the application of the elastin matrix in abstainer animals and of the chitosan matrix in both abstainer and alcoholic animals. Chronic alcohol ingestion resulted in lower bone formation and greater formation of fibrous connective tissue. Full article

(This article belongs to the Special Issue Chitosan, Chitin, and Cellulose Nanofiber Biomaterials)

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13 pages, 4590 KiB

Open AccessArticle

Catalyst-Free Crosslinking Modification of Nata-de-Coco-Based Bacterial Cellulose Nanofibres Using Citric Acid for Biomedical Applications

by Rabiu Salihu, Mohamed Nainar Mohamed Ansari, Saiful Izwan Abd Razak, Nurliyana Ahmad Zawawi, Shafinaz Shahir, Mohd Helmi Sani, Muhammad Hanif Ramlee, Mohammed Ahmad Wsoo, Abdul Halim Mohd Yusof, Nadirul Hasraf Mat Nayan and Ahmad Mohammed Gumel

Polymers 2021, 13(17), 2966; https://doi.org/10.3390/polym13172966 - 31 Aug 2021

Cited by 3 | Viewed by 3483

Abstract

Bacterial cellulose (BC) has gained attention among researchers in materials science and bio-medicine due to its fascinating properties. However, BC’s fibre collapse phenomenon (i.e., its inability to reabsorb water after dehydration) is one of the drawbacks that limit its potential. To overcome this, a catalyst-free thermal crosslinking reaction was employed to modify BC using citric acid (CA) without compromising its biocompatibility. FTIR, XRD, SEM/EDX, TGA, and tensile analysis were carried out to evaluate the properties of the modified BC (MBC). The results confirm the fibre crosslinking phenomenon and the improvement of some properties that could be advantageous for various applications. The modified nanofibre displayed an improved crystallinity and thermal stability with increased water absorption/swelling and tensile modulus. The MBC reported here can be used for wound dressings and tissue scaffolding. Full article

(This article belongs to the Special Issue Chitosan, Chitin, and Cellulose Nanofiber Biomaterials)

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15 pages, 3197 KiB

Open AccessArticle

Study of Different Chitosan/Sodium Carboxymethyl Cellulose Proportions in the Development of Polyelectrolyte Complexes for the Sustained Release of Clarithromycin from Matrix Tablets

by Víctor Guarnizo-Herrero, Carlos Torrado-Salmerón, Norma Sofía Torres Pabón, Guillermo Torrado Durán, Javier Morales and Santiago Torrado-Santiago

Polymers 2021, 13(16), 2813; https://doi.org/10.3390/polym13162813 - 21 Aug 2021

Cited by 17 | Viewed by 3147

Abstract

This study investigated the combination of different proportions of cationic chitosan and anionic carboxymethyl cellulose (CMC) for the development of polyelectrolyte complexes to be used as a carrier in a sustained-release system. Analysis via scanning electron microscopy (SEM) Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and powder X-ray diffraction (PXRD) confirmed ionic interactions occur between the chitosan and carboxymethyl cellulose chains, which increases drug entrapment. The results of the dissolution study in acetate buffer (pH 4.2) showed significant increases in the kinetic profiles of clarithromycin for low proportions of chitosan/carboxymethyl cellulose tablets, while the tablets containing only chitosan had high relaxation of chitosan chains and disintegrated rapidly. The Korsmeyer–Peppas kinetic model for the different interpolymer complexes demonstrated that the clarithromycin transport mechanism was controlled by Fickian diffusion. These results suggest that the matrix tablets with different proportions of chitosan/carboxymethyl cellulose enhanced the ionic interaction and enabled the prolonged release of clarithromycin. Full article

(This article belongs to the Special Issue Chitosan, Chitin, and Cellulose Nanofiber Biomaterials)

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14 pages, 2944 KiB

Open AccessArticle

Biosynthesis of Bacterial Cellulose by Extended Cultivation with Multiple Removal of BC Pellicles

by Ekaterina A. Skiba, Nadezhda A. Shavyrkina, Vera V. Budaeva, Anastasia E. Sitnikova, Anna A. Korchagina, Nikolay V. Bychin, Evgenia K. Gladysheva, Igor N. Pavlov, Andrey N. Zharikov, Vladimir G. Lubyansky, Elena N. Semyonova and Gennady V. Sakovich

Polymers 2021, 13(13), 2118; https://doi.org/10.3390/polym13132118 - 28 Jun 2021

Cited by 2 | Viewed by 1975

Abstract

Extended cultivation with multiple removal of BC pellicles is proposed herein as a new biosynthetic process for bacterial cellulose (BC). This method enhances the BC surface area by 5–11 times per unit volume of the growth medium, improving the economic efficiency of biosynthesis. The resultant BC gel-films were thin, transparent, and congruent. The degree of polymerization (DP) and elastic modulus (EM) depended on the number of BC pellicle removals, vessel shape, and volume. The quality of BC from removals II–III to VII was better than from removal I. The process scale-up of 1:40 by volume increased DP by 1.5 times and EM by 5 times. A fact was established that the symbiotic Medusomyces gisevii Sa-12 was adaptable to exhausted growth medium: the medium was able to biosynthesize BC for 60 days, while glucose ran low at 24 days. On extended cultivation, DP and EM were found to decline by 39–64% and 57–65%, respectively. The BC gel-films obtained upon removals I–VI were successfully trialed in experimental tension-free hernioplasty. Full article

(This article belongs to the Special Issue Chitosan, Chitin, and Cellulose Nanofiber Biomaterials)

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13 pages, 3296 KiB

Open AccessArticle

Controlled Polyelectrolyte Association of Chitosan and Carboxylated Nano-Fibrillated Cellulose by Desalting

by Sarah Amine, Alexandra Montembault, Matthieu Fumagalli, Anayancy Osorio-Madrazo and Laurent David

Polymers 2021, 13(12), 2023; https://doi.org/10.3390/polym13122023 - 21 Jun 2021

Cited by 12 | Viewed by 2550

Abstract

We prepared chitosan (CHI) hydrogels reinforced with highly charged cellulose nanofibrils (CNF) by the desalting method. To this end, the screening of electrostatic interactions between CHI polycation and CNF polyanion was performed by adding NaCl at 0.4 mol/L to the chitosan acetate solution and to the cellulose nanofibrils suspension. The polyelectrolyte complexation between CHI polycation and CNF polyanion was then triggered by desalting the CHI/CNF aqueous mixture by multistep dialysis, in large excess of chitosan. Further gelation of non-complexed CHI was performed by alkaline neutralization of the polymer, yielding high reinforcement effects as probed by the viscoelastic properties of the final hydrogel. The results showed that polyelectrolyte association by desalting can be achieved with a polyanionic nanoparticle partner. Beyond obtaining hydrogel with improved mechanical performance, these composite hydrogels may serve as precursor for dried solid forms with high mechanical properties. Full article

(This article belongs to the Special Issue Chitosan, Chitin, and Cellulose Nanofiber Biomaterials)

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25 pages, 8068 KiB

Open AccessArticle

Development of Bioinspired Functional Chitosan/Cellulose Nanofiber 3D Hydrogel Constructs by 3D Printing for Application in the Engineering of Mechanically Demanding Tissues

by Arnaud Kamdem Tamo, Ingo Doench, Lukas Walter, Alexandra Montembault, Guillaume Sudre, Laurent David, Aliuska Morales-Helguera, Mischa Selig, Bernd Rolauffs, Anke Bernstein, Daniel Hoenders, Andreas Walther and Anayancy Osorio-Madrazo

Polymers 2021, 13(10), 1663; https://doi.org/10.3390/polym13101663 - 20 May 2021

Cited by 35 | Viewed by 6245

Abstract

Soft tissues are commonly fiber-reinforced hydrogel composite structures, distinguishable from hard tissues by their low mineral and high water content. In this work, we proposed the development of 3D printed hydrogel constructs of the biopolymers chitosan (CHI) and cellulose nanofibers (CNFs), both without any chemical modification, which processing did not incorporate any chemical crosslinking. The unique mechanical properties of native cellulose nanofibers offer new strategies for the design of environmentally friendly high mechanical performance composites. In the here proposed 3D printed bioinspired CNF-filled CHI hydrogel biomaterials, the chitosan serves as a biocompatible matrix promoting cell growth with balanced hydrophilic properties, while the CNFs provide mechanical reinforcement to the CHI-based hydrogel. By means of extrusion-based printing (EBB), the design and development of 3D functional hydrogel scaffolds was achieved by using low concentrations of chitosan (2.0–3.0% (w/v)) and cellulose nanofibers (0.2–0.4% (w/v)). CHI/CNF printed hydrogels with good mechanical performance (Young’s modulus 3.0 MPa, stress at break 1.5 MPa, and strain at break 75%), anisotropic microstructure and suitable biological response, were achieved. The CHI/CNF composition and processing parameters were optimized in terms of 3D printability, resolution, and quality of the constructs (microstructure and mechanical properties), resulting in good cell viability. This work allows expanding the library of the so far used biopolymer compositions for 3D printing of mechanically performant hydrogel constructs, purely based in the natural polymers chitosan and cellulose, offering new perspectives in the engineering of mechanically demanding hydrogel tissues like intervertebral disc (IVD), cartilage, meniscus, among others. Full article

(This article belongs to the Special Issue Chitosan, Chitin, and Cellulose Nanofiber Biomaterials)

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20 pages, 5280 KiB

Open AccessArticle

Functional Bionanocomposite Fibers of Chitosan Filled with Cellulose Nanofibers Obtained by Gel Spinning

by Sofia Marquez-Bravo, Ingo Doench, Pamela Molina, Flor Estefany Bentley, Arnaud Kamdem Tamo, Renaud Passieux, Francisco Lossada, Laurent David and Anayancy Osorio-Madrazo

Polymers 2021, 13(10), 1563; https://doi.org/10.3390/polym13101563 - 13 May 2021

Cited by 24 | Viewed by 3967

Abstract

Extremely high mechanical performance spun bionanocomposite fibers of chitosan (CHI), and cellulose nanofibers (CNFs) were successfully achieved by gel spinning of CHI aqueous viscous formulations filled with CNFs. The microstructural characterization of the fibers by X-ray diffraction revealed the crystallization of the CHI polymer chains into anhydrous chitosan allomorph. The spinning process combining acidic–basic–neutralization–stretching–drying steps allowed obtaining CHI/CNF composite fibers of high crystallinity, with enhanced effect at incorporating the CNFs. Chitosan crystallization seems to be promoted by the presence of cellulose nanofibers, serving as nucleation sites for the growing of CHI crystals. Moreover, the preferential orientation of both CNFs and CHI crystals along the spun fiber direction was revealed in the two-dimensional X-ray diffraction patterns. By increasing the CNF amount up to the optimum concentration of 0.4 wt % in the viscous CHI/CNF collodion, Young’s modulus of the spun fibers significantly increased up to 8 GPa. Similarly, the stress at break and the yield stress drastically increased from 115 to 163 MPa, and from 67 to 119 MPa, respectively, by adding only 0.4 wt % of CNFs into a collodion solution containing 4 wt % of chitosan. The toughness of the CHI-based fibers thereby increased from 5 to 9 MJ.m⁻³. For higher CNFs contents like 0.5 wt %, the high mechanical performance of the CHI/CNF composite fibers was still observed, but with a slight worsening of the mechanical parameters, which may be related to a minor disruption of the CHI matrix hydrogel network constituting the collodion and gel fiber, as precursor state for the dry fiber formation. Finally, the rheological behavior observed for the different CHI/CNF viscous collodions and the obtained structural, thermal and mechanical properties results revealed an optimum matrix/filler compatibility and interface when adding 0.4 wt % of nanofibrillated cellulose (CNF) into 4 wt % CHI formulations, yielding functional bionanocomposite fibers of outstanding mechanical properties. Full article

(This article belongs to the Special Issue Chitosan, Chitin, and Cellulose Nanofiber Biomaterials)

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11 pages, 2860 KiB

Open AccessArticle

Nanofibrillated Cellulose-Based Aerogels Functionalized with Tajuva (Maclura tinctoria) Heartwood Extract

by Rodrigo Coldebella, Marina Gentil, Camila Berger, Henrique W. Dalla Costa, Cristiane Pedrazzi, Jalel Labidi, Rafael A. Delucis and André L. Missio

Polymers 2021, 13(6), 908; https://doi.org/10.3390/polym13060908 - 16 Mar 2021

Cited by 6 | Viewed by 2462

Abstract

Aerogels are 3-D nanostructures of non-fluid colloidal interconnected porous networks consisting of loosely packed bonded particles that are expanded throughout their volume by gas and exhibit ultra-low density and high specific surface area. Cellulose-based aerogels can be obtained from hydrogels through a drying process, replacing the solvent (water) with air and keeping the pristine three-dimensional arrangement. In this work, hybrid cellulose-based aerogels were produced and their potential for use as dressings was assessed. Nanofibrilated cellulose (NFC) hydrogels were produced by a co-grinding process in a stone micronizer using a kraft cellulosic pulp and a phenolic extract from Maclura tinctoria (Tajuva) heartwood. NFC-based aerogels were produced by freeze followed by lyophilization, in a way that the Tajuva extract acted as a functionalizing agent. The obtained aerogels showed high porosity (ranging from 97% to 99%) and low density (ranging from 0.025 to 0.040 g·cm⁻³), as well a typical network and sheet-like structure with 100 to 300 μm pores, which yielded compressive strengths ranging from 60 to 340 kPa. The reached antibacterial and antioxidant activities, percentage of inhibitions and water uptakes suggest that the aerogels can be used as fluid absorbers. Additionally, the immobilization of the Tajuva extract indicates the potential for dentistry applications. Full article

(This article belongs to the Special Issue Chitosan, Chitin, and Cellulose Nanofiber Biomaterials)

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13 pages, 4883 KiB

Open AccessArticle

Glycerol Assisted Pretreatment of Lignocellulose Wheat Straw Materials as a Promising Approach for Fabrication of Sustainable Fibrous Filler for Biocomposites

by Hamayoun Mahmood, Saqib Mehmood, Ahmad Shakeel, Tanveer Iqbal, Mohsin Ali Kazmi, Abdul Rehman Khurram and Muhammad Moniruzzaman

Polymers 2021, 13(3), 388; https://doi.org/10.3390/polym13030388 - 26 Jan 2021

Cited by 6 | Viewed by 2713

Abstract

Glycerol pretreatment is a promising method for the environmentally-friendly transformation of lignocellulosic materials into sustainable cellulose-rich raw materials (i.e., biopolymer) to fabricate biocomposites. Here, a comparison of aqueous acidified glycerol (AAG) pretreatment of wheat straw (WS) with alkaline, hot water, and dilute acid pretreatments on the thermal and mechanical characteristics of their fabricated composite board is presented. A comparison of total energy expenditure during WS pretreatment with AAG and other solutions was estimated and a comparative influence of AAG processing on lignocellulosic constituents and thermal stability of WS fiber was studied. Results imply that AAG pretreatment was superior in generating cellulose-rich fiber (CRF) as compared to other pretreatments and enhanced the cellulose contents by 90% compared to raw WS fiber. Flexural strength of acidic (40.50 MPa) and hot water treated WS composite (38.71 MPa) was higher compared to the value of 33.57 MPa for untreated composite, but AAG-treated composites exhibited lower values of flexural strength (22.22 MPa) compared to untreated composite samples. Conversely, AAG pretreatment consumed about 56% lesser energy for each kg of WS processed as compared to other pretreatments. These findings recognize that glycerol pretreatment could be a clean and new pretreatment strategy to convert agricultural waste into high-quality CRF as a sustainable raw material source for engineered biocomposite panels. Full article

(This article belongs to the Special Issue Chitosan, Chitin, and Cellulose Nanofiber Biomaterials)

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