Materials

Research

13 pages, 6070 KiB

Open AccessArticle

Three-Dimensional Characterization of Polyurethane Foams Based on Biopolyols

by Lorenleyn De la Hoz Alford, Camila Gomes Peçanha de Souza, Sidnei Paciornik, José Roberto M. d’Almeida, Brenno Santos Leite, Harold C. Avila, Fabien Léonard and Giovanni Bruno

Materials 2023, 16(5), 2118; https://doi.org/10.3390/ma16052118 - 6 Mar 2023

Viewed by 1958

Abstract

Two biopolyol-based foams derived from banana leaves (BL) or stems (BS) were produced, and their compression mechanical behavior and 3D microstructure were characterized. Traditional compression and in situ tests were performed during 3D image acquisition using X-ray microtomography. A methodology of image acquisition, [...] Read more.

Two biopolyol-based foams derived from banana leaves (BL) or stems (BS) were produced, and their compression mechanical behavior and 3D microstructure were characterized. Traditional compression and in situ tests were performed during 3D image acquisition using X-ray microtomography. A methodology of image acquisition, processing, and analysis was developed to discriminate the foam cells and measure their numbers, volumes, and shapes along with the compression steps. The two foams had similar compression behaviors, but the average cell volume was five times larger for the BS foam than the BL foam. It was also shown that the number of cells increased with increasing compression while the average cell volume decreased. Cell shapes were elongated and did not change with compression. A possible explanation for these characteristics was proposed based on the possibility of cell collapse. The developed methodology will facilitate a broader study of biopolyol-based foams intending to verify the possibility of using these foams as green alternatives to the typical petrol-based foams. Full article

(This article belongs to the Special Issue Advanced Biopolymer Materials: Preparation, Characterization and Applications)

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14 pages, 1794 KiB

Open AccessArticle

Natural Cellulose from Ziziphus jujuba Fibers: Extraction and Characterization

by Aicha Amior, Hamid Satha, Fouad Laoutid, Antoniya Toncheva and Philippe Dubois

Materials 2023, 16(1), 385; https://doi.org/10.3390/ma16010385 - 31 Dec 2022

Cited by 7 | Viewed by 2344

Abstract

Nowadays, due to their natural availability, renewability, biodegradability, nontoxicity, light weight and relatively low cost, natural fibers, especially lignocellulosic fibers, present attractive potential to substitute non-eco-friendly synthetic fibers. In this study, Ziziphus jujuba fibers were used, thanks to their low lignin content, as [...] Read more.

Nowadays, due to their natural availability, renewability, biodegradability, nontoxicity, light weight and relatively low cost, natural fibers, especially lignocellulosic fibers, present attractive potential to substitute non-eco-friendly synthetic fibers. In this study, Ziziphus jujuba fibers were used, thanks to their low lignin content, as an alternative of renewable resource for the production of cellulosic fibers with suitable characteristics and minimal time and energy consumption. In fact, due to their valuable chemical composition, it was possible to remove the amorphous fractions and impurities from the fiber surface by applying ultrasounds coupled with alkaline treatment (80 °C, 5 wt.% NaOH), followed by a bleaching step. The efficient dissolution of the noncellulosic compounds was confirmed by Fourier Transform Infrared Spectroscopy (FTIR). The resulted increase in the crystallinity index (from 35.7% to 57.5%), occurred without impacting the crystalline structure of the fibers. The morphological analysis of the fibers evidences the higher surface area of the obtained fibers. Based on the obtained results, Ziziphus jujuba fibers were found to present a suitable sustainable source for the production of cellulosic fibers. Full article

(This article belongs to the Special Issue Advanced Biopolymer Materials: Preparation, Characterization and Applications)

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17 pages, 5460 KiB

Open AccessArticle

Impact-Resistant Poly(3-Hydroxybutyrate)/Poly(ε-Caprolactone)-Based Materials, through Reactive Melt Processing, for Compression-Molding and 3D-Printing Applications

by Fouad Laoutid, Hadrien Lenoir, Adriana Molins Santaeularia, Antoniya Toncheva, Tim Schouw and Philippe Dubois

Materials 2022, 15(22), 8233; https://doi.org/10.3390/ma15228233 - 19 Nov 2022

Cited by 9 | Viewed by 1895

Abstract

Biobased and biocompatible polymers, such as polyhydroxyalkanoates (PHAs), are of great interest for a large range of applications in the spirit of green chemistry and upcoming reuse and recycling strategies. Polyhydroxybutyrate (PHB), as a promising biocompatible polymer belonging to PHAs, is subject to [...] Read more.

Biobased and biocompatible polymers, such as polyhydroxyalkanoates (PHAs), are of great interest for a large range of applications in the spirit of green chemistry and upcoming reuse and recycling strategies. Polyhydroxybutyrate (PHB), as a promising biocompatible polymer belonging to PHAs, is subject to increased research concern regarding the high degree of crystallinity and brittle behavior of the resulting materials. Therefore, the improvement of PHB’s physico-mechanical properties aims to decrease the Young’s modulus values and to increase the ductility of samples. Here, we proposed an ambitious approach to develop melt-processed materials, while combining PHB characteristics with the ductile properties of poly(ε-caprolactone) (PCL). In order to compatibilize the poorly miscible PHB/PCL blends, dicumyl peroxide (DCP) was used as a free-radical promotor of polyester interchain reactions via the reaction extrusion process. The resulting PHB/PCL-DCP materials revealed a slight increase in the elongation at break, and significant improvement in the impact resistance (7.2 kJ.m⁻²) as compared to PHB. Additional decrease in the Young’s modulus values was achieved by incorporating low molecular polyethylene glycol (PEG) as a plasticizer, leading to an important improvement in the impact resistance (15 kJ.m⁻²). Successful 3D printing using fused deposition melting (FDM) of the resulting PHB/PCL-based blends for the design of a prosthetic finger demonstrated the great potential of the proposed approach for the development of next-generation biomaterials. Full article

(This article belongs to the Special Issue Advanced Biopolymer Materials: Preparation, Characterization and Applications)

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18 pages, 6844 KiB

Open AccessArticle

Synthesis and Anticancer Activity of Bagasse Xylan/Resveratrol Graft-Esterified Composite Nanoderivative

by Bin Zhao, Heping Li, Yue Su, Kexin Tian, Zhiming Zou and Wenli Wang

Materials 2022, 15(15), 5166; https://doi.org/10.3390/ma15155166 - 26 Jul 2022

Cited by 3 | Viewed by 1886

Abstract

Biomass materials are high-quality raw materials for the preparation of natural, green and highly active functional materials due to their rich active groups, wide sources and low toxicity. Bagasse xylan (BX) and resveratrol (Res) were used as raw materials to introduce ethylene glycol [...] Read more.

Biomass materials are high-quality raw materials for the preparation of natural, green and highly active functional materials due to their rich active groups, wide sources and low toxicity. Bagasse xylan (BX) and resveratrol (Res) were used as raw materials to introduce ethylene glycol dimethacrylate (EGDMA) via grafting reaction to obtain the intermediate product BX/Res-g-EGDMA. The intermediate was esterified with 3-carboxyphenylboronic acid (3-CBA) to obtain the target product 3-CBA-BX/Res-g-EGDMA. The BX/Res-composite-modified nanoderivative with antitumor activity was synthesized with the nanoprecipitation method. The effects of the reaction conditions on the grafting rate (G) of BX/Res-g-EGDMA and the degree of substitution (DS) of 3-CBA-BX/Res-g-EGDMA were investigated using single-factor experiments. The results showed that under the optimized process conditions, G and DS reached 142.44% and 0.485, respectively. The product was characterized with FTIR, XRD, TG-FTC, ¹H NMR and SEM, and its anticancer activity was simulated and tested. The results showed that 3-CBA-BX/Res-g-EGDMA had a spherical structure with an average particle size of about 100 nm and that its crystalline structure and thermal stability were different from those of the raw materials. In addition, 3-CBA-BX/Res-g-EGDMA showed the best docking activity with 2HE7 with a binding free energy of −6.3 kJ/mol. The inhibition rate of 3-CBA-BX/Res-g-EGDMA on MGC80-3 (gastric cancer cells) reached 36.71 ± 4.93%, which was 18 times higher than that of BX. Therefore, this material could be a potential candidate for biomedical applications. Full article

(This article belongs to the Special Issue Advanced Biopolymer Materials: Preparation, Characterization and Applications)

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20 pages, 3451 KiB

Open AccessArticle

Synthesis and In Vitro/Ex Vivo Characterizations of Ceftriaxone-Loaded Sodium Alginate/poly(vinyl alcohol) Clay Reinforced Nanocomposites: Possible Applications in Wound Healing

by Shabana Bibi, Sadullah Mir, Wajid Rehman, Farid Menaa, Alia Gul, Fatima Saad Salem Alaryani, Ali M. Alqahtani, Sirajul Haq and Magda H. Abdellatif

Materials 2022, 15(11), 3885; https://doi.org/10.3390/ma15113885 - 30 May 2022

Cited by 14 | Viewed by 2649

Abstract

(1) Background: Nanocomposite films are widely applied in the pharmaceutical industry (e.g., nanodrug delivery systems—NDDS). Indeed, these nanomaterials can be produced at a large industrial scale and display valuable properties (e.g., antibacterial, renewability, biodegradability, bioavailability, safety, tissue-specific targeting, and biocompatibility), which can enhance [...] Read more.

(1) Background: Nanocomposite films are widely applied in the pharmaceutical industry (e.g., nanodrug delivery systems—NDDS). Indeed, these nanomaterials can be produced at a large industrial scale and display valuable properties (e.g., antibacterial, renewability, biodegradability, bioavailability, safety, tissue-specific targeting, and biocompatibility), which can enhance the activity of conventional marketed drugs. (2) Aim: To fabricate and investigate the in vitro properties of the antibiotic ceftriaxone sodium (CTX) once encapsulated into sodium alginate (SA)/poly(vinyl alcohol)PVA-clay reinforced nanocomposite films. (3) Methods: Different ratios of the polymers (i.e., SA, PVA) and CTX drug were used for the synthesis of nanocomposite films by solvent casting technique. Montmorillonite (MMT), modified organically, was added as a nanofiller to increase their thermal and mechanical strength. The prepared samples were physically characterized by thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electronic microscopy (SEM), and energy-dispersive X-ray analysis (EDX). The physicochemical behavior (i.e., swelling, erosion, dissolution/drug release behavior and rat skin permeation) was also assessed. Comparisons were made with the currently marketed free CTX dosage form. (4) Results: TGA of the nanoformulation showed increased thermostability. XRD revealed its semi-crystalline nature. SEM depicted a homogeneous drug-loaded SA/PVA nanocomposite with an average size ranging between 300 and 500 nm. EDX confirmed the elemental composition and uniform distribution of mixing components. The water entrapment efficiency study showed that the highest swelling and erosion ratio is encountered with the nanoformulations S100(3) and S100D15(3). Ex vivo permeation revealed a bi-step discharge mode with an early burst liberation chased by continued drug discharge of devised nanoparticles (NPs). The dissolution studies of the drug-loaded polymer nanocomposites elicited sustained pH-dependent drug release. The cumulative drug release was the highest (90.93%) with S100D15(3). (5) Conclusion: S100D15(3) was the finest formulation. To the best of our knowledge, we also pioneered the use of solvent casting for the preparation of such nanoformulations. Polymers and reinforcing agent, concentrations and pH were rate-deterring features for the preparation of the optimized formulation. Thus, CTX-loaded SA/PVA-MMT reinforced nanocomposite appeared as a promising nanodrug delivery system (NDDS) based on its in vitro physicochemical properties. Full article

(This article belongs to the Special Issue Advanced Biopolymer Materials: Preparation, Characterization and Applications)

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12 pages, 2623 KiB

Open AccessArticle

Biopolymer-Based Films from Sodium Alginate and Citrus Pectin Reinforced with SiO₂

by Luís Marangoni Júnior, Camila Rodrigues Fozzatti, Ewelina Jamróz, Roniérik Pioli Vieira and Rosa Maria Vercelino Alves

Materials 2022, 15(11), 3881; https://doi.org/10.3390/ma15113881 - 29 May 2022

Cited by 22 | Viewed by 3224

Abstract

Blend films based on sodium alginate (SA) and citrus pectin (P) reinforced with different concentrations of SiO₂ (0–10% w/w) were developed in this study. From the morphological (SEM) and structural (FT-IR) evaluation, it was verified that the incorporation of [...] Read more.

Blend films based on sodium alginate (SA) and citrus pectin (P) reinforced with different concentrations of SiO₂ (0–10% w/w) were developed in this study. From the morphological (SEM) and structural (FT-IR) evaluation, it was verified that the incorporation of the reinforcing agent did not drastically modify the microstructure of the films, nor did new chemical bonds form. However, the XRD results suggested a slight reduction in the crystallinities of the blends by the incorporation of SiO₂. Among the formulations prepared, the addition of a 5% reinforcing agent was responsible for the simultaneous improvement of mechanical and barrier properties. Comparing the control sample (SA/P) with the SA/P/5.0%SiO₂ film, the tensile strength increased from 27.7 ± 3.7 to 40.6 ± 4.5 MPa, and the water-vapor transmission rate decreased from 319.8 ± 38.7 to 288.9 ± 23.5 g m⁻² day⁻¹. Therefore, SiO_2, as a reinforcing agent in SA/P blends, represents a simple and effective strategy for improving the properties of biopolymer-based films in applications, such as packaging. Full article

(This article belongs to the Special Issue Advanced Biopolymer Materials: Preparation, Characterization and Applications)

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20 pages, 45073 KiB

Open AccessArticle

Antibacterial and Biodegradable Polysaccharide-Based Films for Food Packaging Applications: Comparative Study

by Weronika Janik, Michał Nowotarski, Divine Yutefar Shyntum, Angelika Banaś, Katarzyna Krukiewicz, Stanisław Kudła and Gabriela Dudek

Materials 2022, 15(9), 3236; https://doi.org/10.3390/ma15093236 - 29 Apr 2022

Cited by 23 | Viewed by 3764

Abstract

One of the major objectives of food industry is to develop low-cost biodegradable food packaging films with optimal physicochemical properties, allowing for their large-scale production and providing a variety of applications. To meet the expectations of food industry, we have fabricated a series [...] Read more.

One of the major objectives of food industry is to develop low-cost biodegradable food packaging films with optimal physicochemical properties, allowing for their large-scale production and providing a variety of applications. To meet the expectations of food industry, we have fabricated a series of solution-cast films based on common biodegradable polysaccharides (starch, chitosan and alginate) to be used in food packaging applications. Selected biopolymers were modified by the addition of glycerol and oxidized sucrose (starch), glycerol (chitosan), and glycerol and calcium chloride (alginate), as well as being used to form blends (starch/chitosan and starch/alginate, respectively). A chestnut extract was used to provide antibacterial properties to the preformed materials. The results of our studies showed that each modification reduced the hydrophilic nature of the polymers, making them more suitable for food packaging applications. In addition, all films exhibited much higher barrier properties to oxygen and carbon dioxide than commercially available films, such as polylactic acid, as well as exhibiting antimicrobial properties against model Gram-negative and Gram-positive bacteria (Escherichia coli and Staphylococcus epidermidis, respectively), as well as yeast (Candida albicans). Full article

(This article belongs to the Special Issue Advanced Biopolymer Materials: Preparation, Characterization and Applications)

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16 pages, 3344 KiB

Open AccessArticle

Sodium Alginate–Gelatin Nanoformulations for Encapsulation of Bacillus velezensis and Their Use for Biological Control of Pistachio Gummosis

by Mojde Moradi Pour, Roohallah Saberi Riseh and Yury A. Skorik

Materials 2022, 15(6), 2114; https://doi.org/10.3390/ma15062114 - 13 Mar 2022

Cited by 51 | Viewed by 4126

Abstract

Biopolymer-based nanocomposites are favorable materials for the encapsulation of biofertilizers and biocontrol agents. In this research, sodium alginate, a widely used natural polymer, was extracted and purified from Macrocystis pyrifera. Its composition was confirmed using ¹H NMR and FTIR analyses, and [...] Read more.

Biopolymer-based nanocomposites are favorable materials for the encapsulation of biofertilizers and biocontrol agents. In this research, sodium alginate, a widely used natural polymer, was extracted and purified from Macrocystis pyrifera. Its composition was confirmed using ¹H NMR and FTIR analyses, and its molecular weight and mannuronic acid/guluronic acid ratio were obtained. Sodium alginate–gelatin microcapsules enriched with carbon nanotubes and SiO₂ nanoparticles were prepared to encapsulate Bacillus velezensis, and the biological effects of this formulation on the control of pistachio gummosis and growth parameters were investigated. Microscopy examination showed that the microcapsules had quite globular shapes. XRD confirmed the occurrence of an electrostatic interaction when sodium alginate was blended with gelatin. The survival rate of the encapsulated bacteria was about 10⁷ CFU/mL and was maintained after one year of storage. The aim of this study was to achieve a unique formulation containing beneficial bacteria and nanoparticles for the synergistic control of Phytophthora drechsleri. Full article

(This article belongs to the Special Issue Advanced Biopolymer Materials: Preparation, Characterization and Applications)

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17 pages, 17525 KiB

Open AccessArticle

Active Double-Layered Films Enriched with AgNPs in Great Water Dock Root and Pu-Erh Extracts

by Ewelina Jamróz, Agnieszka Cabaj, Lesław Juszczak, Joanna Tkaczewska, Małgorzata Zimowska, Agnieszka Cholewa-Wójcik, Paweł Krzyściak and Pavel Kopel

Materials 2021, 14(22), 6925; https://doi.org/10.3390/ma14226925 - 16 Nov 2021

Cited by 12 | Viewed by 2558

Abstract

A novel, eco-friendly, and biocompatible method was applied to form silver nanoparticles (AgNPs) in great water dock (Lapathi radix) (KB) and pu-erh (Camellia sinensis) (PE) extracts. The surface plasma resonance peak of green synthesized AgNPs at 451.8 nm for [...] Read more.

A novel, eco-friendly, and biocompatible method was applied to form silver nanoparticles (AgNPs) in great water dock (Lapathi radix) (KB) and pu-erh (Camellia sinensis) (PE) extracts. The surface plasma resonance peak of green synthesized AgNPs at 451.8 nm for AgNPs+KB and 440.8 nm for AgNPs+PE was observed via spectral analysis of UV absorbance. In this study, double-layered biopolymer films (FUR/CHIT+HGEL) with AgNPs incorporated in KB solution (AgNPs+KB) and AgNPs in PE solution (AgNPs+PE), were successfully prepared using the casting method. The SEM, XRD, zeta potential and size analyses confirmed the presence of AgNP in the films. The addition of AgNPs in plant extracts improved antimicrobial and antioxidant activity and thermal stability, whereas WVTR experienced a decrease. The nanocomposite films’ orange-brown colour may aid in the protection of food products against UV rays. The composite films demonstrated antibacterial activity against food-borne pathogens and may offer potential in food packaging applications. Full article

(This article belongs to the Special Issue Advanced Biopolymer Materials: Preparation, Characterization and Applications)

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11 pages, 1450 KiB

Open AccessArticle

Effect of Free Volume on Curcumin Release from Various Polymer-Based Composite Films Analyzed Using Positron Annihilation Lifetime Spectroscopy

by Jong-Whan Rhim, Saygin Kuzeci, Swarup Roy, Necmettin Akti, Cumali Tav and Ugur Yahsi

Materials 2021, 14(19), 5679; https://doi.org/10.3390/ma14195679 - 29 Sep 2021

Cited by 10 | Viewed by 2367

Abstract

This work reports the effects of free volume on curcumin release in various polymer-based composite films. Curcumin-reinforced biocomposite films were fabricated with natural biopolymers (carrageenan and chitosan) and bioplastics (poly(lactide) (PLA) and poly (butylene adipate-co-terephthalate) (PBAT)) via the solvent casting method. The curcumin [...] Read more.

This work reports the effects of free volume on curcumin release in various polymer-based composite films. Curcumin-reinforced biocomposite films were fabricated with natural biopolymers (carrageenan and chitosan) and bioplastics (poly(lactide) (PLA) and poly (butylene adipate-co-terephthalate) (PBAT)) via the solvent casting method. The curcumin release test was performed using an aqueous medium, and it was found that it was released the fastest in the carrageenan film, followed by the chitosan, PLA, and PBAT films, presumably owing to the dissimilarity of the polymer matrix. The free volume of the polymer films was determined using positron annihilation lifetime spectroscopy (PALS) to understand the release phenomena of curcumin. The free volume fraction was varied and reliant on the type of polymer, with the highest in the PBAT-based film followed by the PLA-, chitosan-, and carrageenan-based films. The free volume method helps analyze the release of bioactive compounds in a polymer matrix and may help to achieve a better understanding of the release of bioactive compounds. Full article

(This article belongs to the Special Issue Advanced Biopolymer Materials: Preparation, Characterization and Applications)

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17 pages, 1402 KiB

Open AccessArticle

The Application of Spray-Dried and Reconstituted Flaxseed Oil Cake Extract as Encapsulating Material and Carrier for Probiotic Lacticaseibacillus rhamnosus GG

by Łukasz Łopusiewicz, Elżbieta Bogusławska-Wąs, Emilia Drozłowska, Paulina Trocer, Alicja Dłubała, Kinga Mazurkiewicz-Zapałowicz and Artur Bartkowiak

Materials 2021, 14(18), 5324; https://doi.org/10.3390/ma14185324 - 15 Sep 2021

Cited by 12 | Viewed by 3043

Abstract

Agro-industrial by-products are promising source of biopolymers, including proteins and polysaccharides. This study was designed to evaluate the flaxseed oil cake extract (FOCE) as natural encapsulating material and carrier for probiotic Lacticaseibacillus rhamnous GG (LGG). The powders were obtained using three spray drying [...] Read more.

Agro-industrial by-products are promising source of biopolymers, including proteins and polysaccharides. This study was designed to evaluate the flaxseed oil cake extract (FOCE) as natural encapsulating material and carrier for probiotic Lacticaseibacillus rhamnous GG (LGG). The powders were obtained using three spray drying inlet temperatures (110 °C, 140 °C, 170 °C), and reconstituted. The influence of temperature on water activity, morphology, chemical composition, flowability and cohesiveness of the powders was estimated. For all variants, the survival of bacteria during spray drying, and simulated passage through the gastrointestinal tract was evaluated. The preservation of LGG probiotic features such as cholesterol reduction, hydrophobicity and adhesion to mucin were examined. Results revealed that all physicochemical and functional characteristics of the powders were affected by the inlet temperature. This study demonstrated that FOCE is an appropriate matrix for spray drying (due to flaxseed proteins and polysaccharides) providing high survivability of bacteria (89.41–96.32%), that passed meaningfully through the simulated gastrointestinal tract (4.39–5.97 log reduction), largely maintaining their probiotic properties, being a promising environmentally-friendly carrier for probiotic LGG. Full article

(This article belongs to the Special Issue Advanced Biopolymer Materials: Preparation, Characterization and Applications)

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16 pages, 2858 KiB

Open AccessArticle

Development and Characterization of Active Gelatin Films Loaded with Rapeseed Meal Extracts

by Alicja Tymczewska, Bliss Ursula Furtado, Jacek Nowaczyk, Katarzyna Hrynkiewicz and Aleksandra Szydłowska-Czerniak

Materials 2021, 14(11), 2869; https://doi.org/10.3390/ma14112869 - 27 May 2021

Cited by 12 | Viewed by 2717

Abstract

The use of industrial waste as a material for the development of natural innovative and active packaging is economically and environmentally appealing. The aim of this study was to develop and characterize active gelatin films incorporating rapeseed oil industry waste. Water (RM-WE) and [...] Read more.

The use of industrial waste as a material for the development of natural innovative and active packaging is economically and environmentally appealing. The aim of this study was to develop and characterize active gelatin films incorporating rapeseed oil industry waste. Water (RM-WE) and methanolic (RM-MWE) extracts of rapeseed meal (RM) were used as active agents in film formulations. The active films were produced by a casting technique. The physicochemical, mechanical, optical, morphological, radical scavenging, and antibacterial properties of the films were analyzed. The addition of RM-WE and RM-MWE in the concentrations range between 4 and 12% promoted an increase of Young’s modulus (YM) and radical scavenging properties of films investigated by the direct QUick, Easy, New, CHEap and Reproducible procedure using 2,2-diphenyl-1-picrylhydrazyl (QUENCHER_DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (QUENCHER_ABTS) radicals. The antibacterial properties of films were examined against five bacterial strains: E. coli, S. enterica, M. luteus, L. monocytogenes, and S. aureus. Additionally, color and opacity of the control and fortified films differed significantly. The gelatin films with RM extracts are resistant to the microbial spoilage and could be used to produce active packaging for food that is vulnerable to rancidity effects. Full article

(This article belongs to the Special Issue Advanced Biopolymer Materials: Preparation, Characterization and Applications)

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15 pages, 7294 KiB

Open AccessArticle

Evaluation of Dynamic Properties of Sodium-Alginate-Reinforced Soil Using A Resonant-Column Test

by Seongnoh Ahn, Jae-Eun Ryou, Kwangkuk Ahn, Changho Lee, Jun-Dae Lee and Jongwon Jung

Materials 2021, 14(11), 2743; https://doi.org/10.3390/ma14112743 - 22 May 2021

Cited by 7 | Viewed by 2837

Abstract

Ground reinforcement is a method used to reduce the damage caused by earthquakes. Usually, cement-based reinforcement methods are used because they are inexpensive and show excellent performance. Recently, however, reinforcement methods using eco-friendly materials have been proposed due to environmental issues. In this [...] Read more.

Ground reinforcement is a method used to reduce the damage caused by earthquakes. Usually, cement-based reinforcement methods are used because they are inexpensive and show excellent performance. Recently, however, reinforcement methods using eco-friendly materials have been proposed due to environmental issues. In this study, the cement reinforcement method and the biopolymer reinforcement method using sodium alginate were compared. The dynamic properties of the reinforced ground, including shear modulus and damping ratio, were measured through a resonant-column test. Also, the viscosity of sodium alginate solution, which is a non-Newtonian fluid, was also explored and found to increase with concentration. The maximum shear modulus and minimum damping ratio increased, and the linear range of the shear modulus curve decreased, when cement and sodium alginate solution were mixed. Addition of biopolymer showed similar reinforcing effect in a lesser amount of additive compared to the cement-reinforced ground, but the effect decreased above a certain viscosity because the biopolymer solution was not homogeneously distributed. This was examined through a shear-failure-mode test. Full article

(This article belongs to the Special Issue Advanced Biopolymer Materials: Preparation, Characterization and Applications)

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17 pages, 4020 KiB

Open AccessArticle

Novel Polymeric Biomaterial Based on Naringenin

by Malgorzata Latos-Brozio, Anna Masek and Małgorzata Piotrowska

Materials 2021, 14(9), 2142; https://doi.org/10.3390/ma14092142 - 23 Apr 2021

Cited by 24 | Viewed by 2898

Abstract

Biomaterials prepared based on raw plant materials are becoming more and more popular due to their specific properties and environmental friendliness. Naringenin is a flavonoid naturally occurring in citrus fruit with antioxidant and pharmacological activity. Polymeric materials based on flavonoids may have favorable [...] Read more.

Biomaterials prepared based on raw plant materials are becoming more and more popular due to their specific properties and environmental friendliness. Naringenin is a flavonoid naturally occurring in citrus fruit with antioxidant and pharmacological activity. Polymeric materials based on flavonoids may have favorable properties in comparison to monomeric polyphenols, such as stronger antioxidant and antimicrobial properties. One of the methods of obtaining the polymeric form of flavonoids is polymerization with a cross-linking compound. This method has already been used to obtain poly(quercetin) and poly(rutin) from a flavonol group as well as poly(catechin) from the flavan-3-ol group of flavonoids. However, to date, no polymeric forms of flavanones have been prepared in a cross-linking reaction; the aim of this study was to obtain poly(naringenin) by reaction with a cross-linking compound using glycerol diglycide ether GDE. The degree of conversion of naringenin to poly(naringenin) determined by FTIR spectroscopy was 85%. In addition, the thermal, antioxidant and antimicrobial properties of poly(naringenin) were analyzed. Poly(naringenin) was characterized by greater resistance to oxidation and better thermal stability than monomeric naringenin. Moreover, polymeric naringenin also had a better ability to scavenge ABTS and DPPH free-radicals. In contrast to monomeric form, poly(naringenin) had antimicrobial activity against Candida albicans. Polymeric biomaterial based on naringenin could potentially be used as a natural stabilizer and antimicrobial additive for polymer compositions, as well as pro-ecological materials. Full article

(This article belongs to the Special Issue Advanced Biopolymer Materials: Preparation, Characterization and Applications)

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14 pages, 4041 KiB

Open AccessArticle

Characterizing Mat Formation of Bamboo Fiber Composites: Horizontal Density Distribution

by Yu’an Hu, Mei He, Kate Semple, Meiling Chen, Hugo Pineda, Chenli Zhou and Chunping Dai

Materials 2021, 14(5), 1198; https://doi.org/10.3390/ma14051198 - 4 Mar 2021

Cited by 10 | Viewed by 2336

Abstract

Bamboo fiber composite (BFC) is a unidirectional and continuous bamboo fiber composite manufactured by consolidation and gluing of flattened, partially separated bamboo culm strips into thick and dense panels. The composite mechanical properties are primarily influenced by panel density, its variation and uniformity. [...] Read more.

Bamboo fiber composite (BFC) is a unidirectional and continuous bamboo fiber composite manufactured by consolidation and gluing of flattened, partially separated bamboo culm strips into thick and dense panels. The composite mechanical properties are primarily influenced by panel density, its variation and uniformity. This paper characterized the horizontal density distribution (HDD) within BFC panels and its controlling factors. It revealed that HDD follows a normal distribution, with its standard deviation (SD) strongly affected by sampling specimen size, panel thickness and panel locations. SD was lowest in the thickest (40 mm) panel and largest-size (150 × 150-mm²) specimens. There was also a systematic variation along the length of the BFC due to the tapering effect of bamboo culm thickness. Density was higher along panel edges due to restraint from the mold edges during hot pressing. The manual BFC mat forming process is presented and found to effectively minimize the density variation compared to machine-formed wood composites. This study provides a basic understanding of and a quality control guide to the formation uniformity of BFC products. Full article

(This article belongs to the Special Issue Advanced Biopolymer Materials: Preparation, Characterization and Applications)

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