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Environmentally Friendly Polymeric Blends from Renewable Sources

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A special issue of Materials (ISSN 1996-1944). This special issue belongs to the section "Advanced Composites".

Deadline for manuscript submissions: closed (31 May 2021) | Viewed by 36436

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Special Issue Editors

Prof. Dr. Barbara Gawdzik

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Guest Editor

Department of Polymer Chemistry, Maria Curie-Sklodowska University, Lublin, Poland
Interests: synthesis of new monomers and polymers; chemical modification of synthetic and natural polymers; synthesis of porous polymers for applications in various chromatographic techniques; synthesis of novel polymer-based adsorbents having desired properties for health and environmental protection; synthesis and applications of imprinted polymers; synthesis and investigations of carbon adsorbents from synthetic and natural polymers; chromatographic analysis; investigations of porous structure of polymeric materials; use of recycled polymers in the synthesis; environmental protection, wasteless processes.
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Dr. Olena Sevastyanova

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Guest Editor

Department of Fiber and Polymer Technology, KTH Royal Institute of Technology, Stockholm, Sweden
Interests: carbohydrate chemistry; cellulosic materials; polymer chemistry; bio-based composites
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Materials from renewable resources have attracted increasing attention in the past decades as a result of environmental concerns and due to the depletion of petroleum resources. Polymeric materials from renewable sources have a long history. They were used in ancient times and later accompanied man along with the development of civilization. Currently, they are widespread in many areas of life and used, for example, in packaging and in the automotive and pharmaceutical industries.

Polymers from renewable resources are generally classified into three groups: i) Natural polymers, such as cellulose, starch, and proteins; ii) synthetic polymers from natural monomers, such as poly(lactic acid); and iii) polymers from microbial processes, such as poly(hydroxybutyrate). The emergence of new methods and analytical tools provides a new level of understanding of the structure–properties relationship of natural polymers and allows the development of materials for new applications.

One of the attractive properties of the natural polymers and synthetic polymers produced from natural monomers is their inherited biodegradability. However, this is related to their moisture sensitivity, which limits their application. Other important limitations of most polymers from renewable resources are their lower softening temperature and mechanical strength. These and many other properties of polymers can be modified and improved through the blending of two or more compounds, for example, two or more polymers, polymers and fibers, polymers and nanoparticles, etc.

A blending approach is an effective way to achieve a desirable combination of properties which are often absent in the individual components. The final properties can be modified by changing the relative concentration and kind of monomeric units used in the synthesis or by varying the proportion of homopolymers and various additives in a blend composition. Development of effective methods of manufacturing products from blends of renewable polymers and environmentally friendly synthetic polymers in a controlled way is the challenge of our time.

The aim of this Special Issue is to highlight progress in the manufacturing, characterization, and applications of environmentally friendly polymeric blends from renewable resources. It is our pleasure to invite you to submit your manuscript for it.

Prof. Barbara Gawdzik
Dr. Olena Sevastyanova
Guest Editors

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Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Materials is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

Polymer blends
Renewable resources
Environmentally friendly polymers
Biodegradability

Published Papers (14 papers)

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Editorial

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4 pages, 192 KiB

Open AccessEditorial

Special Issue: “Environmentally Friendly Polymeric Blends from Renewable Sources”

by Barbara Gawdzik and Olena Sevastyanova

Materials 2021, 14(17), 4858; https://doi.org/10.3390/ma14174858 - 26 Aug 2021

Cited by 1 | Viewed by 1453

Abstract

The aim of this Special Issue is to highlight the progress in the manufacturing,
characterization, and applications of environmentally friendly polymeric blends from renewable resources [...] Full article

(This article belongs to the Special Issue Environmentally Friendly Polymeric Blends from Renewable Sources)

Research

Jump to: Editorial

14 pages, 3315 KiB

Open AccessArticle

Synthesis, Characterization and Testing of Antimicrobial Activity of Composites of Unsaturated Polyester Resins with Wood Flour and Silver Nanoparticles

by Przemysław Pączkowski, Andrzej Puszka, Malgorzata Miazga-Karska, Grażyna Ginalska and Barbara Gawdzik

Materials 2021, 14(5), 1122; https://doi.org/10.3390/ma14051122 - 27 Feb 2021

Cited by 16 | Viewed by 2146

Abstract

This paper presents the properties of the wood-resin composites. For improving their antibacterial character, silver nanoparticles were incorporated into their structures. The properties of the obtained materials were analyzed in vitro for their anti-biofilm potency in contact with aerobic Gram-positive Staphylococcus aureus and Staphylococcus epidermidis; and aerobic Gram-negative Escherichia coli and Pseudomonas aeruginosa. These pathogens are responsible for various infections, including those associated with healthcare. The effect of silver nanoparticles incorporation on mechanical and thermomechanical properties as well as gloss were investigated for the samples of composites before and after accelerating aging tests. The results show that bacteria can colonize in various wrinkles and cracks on the composites with wood flour but also the surface of the cross-linked unsaturated polyester resin. The addition of nanosilver causes the death of bacteria. It also positively influences mechanical and thermomechanical properties as well as gloss of the resin. Full article

(This article belongs to the Special Issue Environmentally Friendly Polymeric Blends from Renewable Sources)

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18 pages, 8692 KiB

Open AccessArticle

Polyurethane Hybrid Composites Reinforced with Lavender Residue Functionalized with Kaolinite and Hydroxyapatite

by Sylwia Członka, Agnė Kairytė, Karolina Miedzińska and Anna Strąkowska

Materials 2021, 14(2), 415; https://doi.org/10.3390/ma14020415 - 15 Jan 2021

Cited by 25 | Viewed by 2652

Abstract

Polyurethane (PUR) composites were modified with 2 wt.% of lavender fillers functionalized with kaolinite (K) and hydroxyapatite (HA). The impact of lavender fillers on selected properties of PUR composites, such as rheological properties (dynamic viscosity, foaming behavior), mechanical properties (compressive strength, flexural strength, impact strength), insulation properties (thermal conductivity), thermal characteristic (temperature of thermal decomposition stages), flame retardancy (e.g., ignition time, limiting oxygen index, heat peak release) and performance properties (water uptake, contact angle) was investigated. Among all modified types of PUR composites, the greatest improvement was observed for PUR composites filled with lavender fillers functionalized with kaolinite and hydroxyapatite. For example, on the addition of functionalized lavender fillers, the compressive strength was enhanced by ~16–18%, flexural strength by ~9–12%, and impact strength by ~7%. Due to the functionalization of lavender filler with thermally stable flame retardant compounds, such modified PUR composites were characterized by higher temperatures of thermal decomposition. Most importantly, PUR composites filled with flame retardant compounds exhibited improved flame resistance characteristics—in both cases, the value of peak heat release was reduced by ~50%, while the value of total smoke release was reduced by ~30%. Full article

(This article belongs to the Special Issue Environmentally Friendly Polymeric Blends from Renewable Sources)

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15 pages, 4685 KiB

Open AccessArticle

Rigid Polyurethane Foams Reinforced with POSS-Impregnated Sugar Beet Pulp Filler

by Anna Strąkowska, Sylwia Członka and Agnė Kairytė

Materials 2020, 13(23), 5493; https://doi.org/10.3390/ma13235493 - 2 Dec 2020

Cited by 20 | Viewed by 2281

Abstract

Rigid polyurethane (PUR) foams were reinforced with sugar beet pulp (BP) impregnated with Aminopropylisobutyl-polyhedral oligomeric silsesquioxanes (APIB-POSS). BP filler was incorporated into PUR at different percentages—1, 2, and 5 wt.%. The impact of BP filler on morphology features, mechanical performances, and thermal stability of PUR was examined. The results revealed that the greatest improvement in physico-mechanical properties was observed at lower concentrations (1 and 2 wt.%) of BP filler. For example, when compared with neat PUR foams, the addition of 2 wt.% of BP resulted in the formation of PUR composite foams with increased compressive strength (~12%), greater flexural strength (~12%), and better impact strength (~6%). The results of thermogravimetric analysis (TGA) revealed that, due to the good thermal stability of POSS-impregnated BP filler, the reinforced PUR composite foams were characterized by better thermal stability—for example, by increasing the content of BP filler up to 5 wt.%, the mass residue measured at 600 °C increased from 29.0 to 31.9%. Moreover, the addition of each amount of filler resulted in the improvement of fire resistance of PUR composite foams, which was determined by measuring the value of heat peak release (pHRR), total heat release (THR), total smoke release (TSR), limiting oxygen index (LOI), and the amount of carbon monoxide (CO) and carbon dioxide (CO₂) released during the combustion. The greatest improvement was observed for PUR composite foams with 2 wt.% of BP filler. The results presented in the current study indicate that the addition of a proper amount of POSS-impregnated BP filler may be an effective approach to the synthesis of PUR composites with improved physico-mechanical properties. Due to the outstanding properties of PUR composite foams reinforced with POSS-impregnated BP, such developed materials may be successfully used as thermal insulation materials in the building and construction industry. Full article

(This article belongs to the Special Issue Environmentally Friendly Polymeric Blends from Renewable Sources)

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17 pages, 4324 KiB

Open AccessArticle

The Impact of Hemp Shives Impregnated with Selected Plant Oils on Mechanical, Thermal, and Insulating Properties of Polyurethane Composite Foams

by Sylwia Członka, Anna Strąkowska and Agnė Kairytė

Materials 2020, 13(21), 4709; https://doi.org/10.3390/ma13214709 - 22 Oct 2020

Cited by 25 | Viewed by 2405

Abstract

Polyurethane (PUR) foams reinforced with 2 wt.% hemp shives (HS) fillers were successfully synthesized. Three different types of HS fillers were evaluated—non-treated HS, HS impregnated with sunflower oil (SO) and HS impregnated with tung oil (TO). The impact of each type of HS fillers on cellular morphology, mechanical performances, thermal stability, and flame retardancy was evaluated. It has been shown that the addition of HS fillers improved the mechanical characteristics of PUR foams. Among all modified series, the greatest improvement was observed after the incorporation of non-treated HS filler—when compared with neat foams, the value of compressive strength increased by ~13%. Moreover, the incorporation of impregnated HS fillers resulted in the improvement of thermal stability and flame retardancy of PUR foams. For example, the addition of both types of impregnated HS fillers significantly decreased the value of heat peak release (pHRR), total smoke release (TSR), and limiting oxygen index (LOI). Moreover, the PUR foams containing impregnated fillers were characterized by improved hydrophobicity and limited water uptake. The obtained results confirmed that the modification of PUR foams with non-treated and impregnated HS fillers may be a successful approach in producing polymeric composites with improved properties. Full article

(This article belongs to the Special Issue Environmentally Friendly Polymeric Blends from Renewable Sources)

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20 pages, 3504 KiB

Open AccessArticle

The Eco-Friendly Biochar and Valuable Bio-Oil from Caragana korshinskii: Pyrolysis Preparation, Characterization, and Adsorption Applications

by Tongtong Wang, Hongtao Liu, Cuihua Duan, Rui Xu, Zhiqin Zhang, Diao She and Jiyong Zheng

Materials 2020, 13(15), 3391; https://doi.org/10.3390/ma13153391 - 31 Jul 2020

Cited by 28 | Viewed by 3190

Abstract

Carbonization of biomass can prepare carbon materials with excellent properties. In order to explore the comprehensive utilization and recycling of Caragana korshinskii biomass, 15 kinds of Caragana korshinskii biochar (CB) were prepared by controlling the oxygen-limited pyrolysis process. Moreover, we pay attention to the dynamic changes of microstructure of CB and the by-products. The physicochemical properties of CB were characterized by Scanning Electron Microscope (SEM), BET-specific surface area (BET-SSA), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), and Gas chromatography-mass spectrometry (GC-MS). The optimal preparation technology was evaluated by batch adsorption application experiment of NO₃⁻, and the pyrolysis mechanism was explored. The results showed that the pyrolysis temperature is the most important factor in the properties of CB. With the increase of temperature, the content of C, pH, mesoporous structure, BET-SSA of CB increased, the cation exchange capacity (CEC) decreased and then increased, but the yield and the content of O and N decreased. The CEC, pH, and BET-SSA of CB under each pyrolysis process were 16.64–81.4 cmol·kg⁻¹, 6.65–8.99, and 13.52–133.49 m²·g⁻¹, respectively. CB contains abundant functional groups and mesoporous structure. As the pyrolysis temperature and time increases, the bond valence structure of C 1s, Ca 2p, and O 1s is more stable, and the phase structure of CaCO₃ is more obvious, where the aromaticity increases, and the polarity decreases. The CB prepared at 650 °C for 3 h presented the best adsorption performance, and the maximum theoretical adsorption capacity for NO₃⁻ reached 120.65 mg·g⁻¹. The Langmuir model and pseudo-second-order model can well describe the isothermal and kinetics adsorption process of NO₃⁻, respectively. Compared with other cellulose and lignin-based biomass materials, CB showed efficient adsorption performance of NO₃⁻ without complicated modification condition. The by-products contain bio-soil and tail gas, which are potential source of liquid fuel and chemical raw materials. Especially, the bio-oil of CB contains α-d-glucopyranose, which can be used in medical tests and medicines. Full article

(This article belongs to the Special Issue Environmentally Friendly Polymeric Blends from Renewable Sources)

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16 pages, 4013 KiB

Open AccessArticle

Rigid Polyurethane Foams Based on Bio-Polyol and Additionally Reinforced with Silanized and Acetylated Walnut Shells for the Synthesis of Environmentally Friendly Insulating Materials

by Sylwia Członka and Anna Strąkowska

Materials 2020, 13(15), 3245; https://doi.org/10.3390/ma13153245 - 22 Jul 2020

Cited by 20 | Viewed by 2537

Abstract

Rigid polyurethane (PUR) foams produced from walnut shells-derived polyol (20 wt.%) were successfully reinforced with 2 wt.% of non-treated, acetylated, and silanized walnut shells (WS). The impact of non-treated and chemically-treated WS on the morphology, mechanical, and thermal characteristics of PUR composites was determined. The morphological analysis confirmed that the addition of WS fillers promoted a reduction in cell size, compared to pure PUR foams. Among all the modified PUR foams, the greatest improvement of mechanical characteristics was observed for PUR foams with the addition of silanized WS—the compressive, flexural, and impact strength were enhanced by 21, 16, and 13%, respectively. The addition of non-treated and chemically-treated WS improved the thermomechanical stability of PUR foams. The results of the dynamic mechanical analysis confirmed an increase in glass transition temperature and storage modulus of PUR foams after the incorporation of chemically-treated WS. The addition of non-treated and chemically-treated WS did not affect the insulating properties of PUR foams, and the thermal conductivity value did not show any significant improvement and deterioration due to the addition of WS fillers. Full article

(This article belongs to the Special Issue Environmentally Friendly Polymeric Blends from Renewable Sources)

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16 pages, 4256 KiB

Open AccessArticle

Biocomposites from Rice Straw Nanofibers: Morphology, Thermal and Mechanical Properties

by José Carlos Alcántara, Israel González, M. Mercè Pareta and Fabiola Vilaseca

Materials 2020, 13(9), 2138; https://doi.org/10.3390/ma13092138 - 5 May 2020

Cited by 25 | Viewed by 3636

Abstract

Agricultural residues are major potential resources for biomass and for material production. In this work, rice straw residues were used to isolate cellulose nanofibers of different degree of oxidation. Firstly, bleached rice fibers were produced from the rice straw residues following chemical extraction and bleaching processes. Oxidation of rice fibers mediated by radical 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO) at pH 10 was then applied to extract rice cellulose nanofibers, with diameters of 3–11 nm from morphological analysis. The strengthening capacity of rice nanofibers was tested by casting nanocomposite films with poly(vinyl alcohol) polymer. The same formulations with eucalyptus nanofibers were produced as comparison. Their thermal and mechanical performance was evaluated using thermogravimetry, differential scanning calorimetry, dynamic mechanical analysis and tensile testing. The glass transition of nanocomposites was shifted to higher temperatures with respect to the pure polymer by the addition of rice cellulose nanofibers. Rice nanofibers also acted as a nucleating agent for the polymer matrix. More flexible eucalyptus nanofibers did not show these two phenomena on the matrix. Instead, both types of nanofibers gave similar stiffening (as Young’s modulus) to the matrix reinforced up to 5 wt.%. The ultimate tensile strength of nanocomposite films revealed significant enhancing capacity for rice nanofibers, although this effect was somehow higher for eucalyptus nanofibers. Full article

(This article belongs to the Special Issue Environmentally Friendly Polymeric Blends from Renewable Sources)

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15 pages, 2718 KiB

Open AccessArticle

Nanocomposite Polymeric Materials Based on Eucalyptus Lignoboost^® Kraft Lignin for Liquid Sensing Applications

by Sónia S. Leça Gonçalves, Alisa Rudnitskaya, António J.M. Sales, Luís M. Cadillon Costa and Dmitry V. Evtuguin

Materials 2020, 13(7), 1637; https://doi.org/10.3390/ma13071637 - 2 Apr 2020

Cited by 13 | Viewed by 2252

Abstract

This study reports the synthesis of polyurethane–lignin copolymer blended with carbon multilayer nanotubes to be used in all-solid-state potentiometric chemical sensors. Known applicability of lignin-based polyurethanes doped with carbon nanotubes for chemical sensing was extended to eucalyptus LignoBoost^® kraft lignin containing increased amounts of polyphenolic groups from concomitant tannins that were expected to impart specificity and sensitivity to the sensing material. Synthesized polymers were characterized using FT-MIR spectroscopy, electrical impedance spectroscopy, scanning electron microscopy, thermogravimetric analysis, and differential scanning calorimetry and are used for manufacturing of all solid-state potentiometric sensors. Potentiometric sensor with LignoBoost^® kraft lignin-based polyurethane membrane displayed theoretical response and high selectivity to Cu (II) ions, as well as long-term stability. Full article

(This article belongs to the Special Issue Environmentally Friendly Polymeric Blends from Renewable Sources)

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13 pages, 2896 KiB

Open AccessArticle

Composites of Unsaturated Polyester Resins with Microcrystalline Cellulose and Its Derivatives

by Artur Chabros, Barbara Gawdzik, Beata Podkościelna, Marta Goliszek and Przemysław Pączkowski

Materials 2020, 13(1), 62; https://doi.org/10.3390/ma13010062 - 21 Dec 2019

Cited by 30 | Viewed by 3243

Abstract

The paper investigates the properties of unsaturated polyester resins and microcrystalline cellulose (MCC) composites. The influence of MCC modification on mechanical, thermomechanical, and thermal properties of obtained materials was discussed. In order to reduce the hydrophilic character of the MCC surface, it was subjected to esterification with the methacrylic anhydride. This resulted in hydroxyl groups blocking and, additionally, the introduction of unsaturated bonds into its structure, which could participate in copolymerization with the curing resin. Composites of varying amounts of cellulose as a filler were obtained from modified MCC and unmodified (comparative) MCC. The modification of MCC resulted in obtaining composites characterized by greater flexural strength and strain at break compared with the analogous composites based on the unmodified MCC. Full article

(This article belongs to the Special Issue Environmentally Friendly Polymeric Blends from Renewable Sources)

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14 pages, 2428 KiB

Open AccessArticle

Explorative Study on the Use of Curauá Reinforced Polypropylene Composites for the Automotive Industry

by Marc Delgado-Aguilar, Quim Tarrés, María de Fátima V. Marques, Francesc X. Espinach, Fernando Julián, Pere Mutjé and Fabiola Vilaseca

Materials 2019, 12(24), 4185; https://doi.org/10.3390/ma12244185 - 12 Dec 2019

Cited by 18 | Viewed by 2641

Abstract

The automotive industry is under a growing volume of regulations regarding environmental impact and component recycling. Nowadays, glass fiber-based composites are commodities in the automotive industry, but show limitations when recycled. Thus, attention is being devoted to alternative reinforcements like natural fibers. Curauá (Curacao, Ananas erectifolius) is reported in the literature as a promising source of natural fiber prone to be used as composite reinforcement. Nonetheless, one important challenge is to obtain properly dispersed materials, especially when the percentages of reinforcements are higher than 30 wt %. In this work, composite materials with curauá fiber contents ranging from 20 wt % to 50 wt % showed a linear positive evolution of its tensile strength and Young’s modulus against reinforcement content. This is an indication of good reinforcement dispersion and of favorable stress transfer at the fiber-matrix interphase. A car door handle was used as a test case to assess the suitability of curauá-based composites to replace glass fiber-reinforced composites. The mechanical analysis and a preliminary lifecycle analysis are performed to prove such ability. Full article

(This article belongs to the Special Issue Environmentally Friendly Polymeric Blends from Renewable Sources)

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13 pages, 2276 KiB

Open AccessArticle

Biobased Composites from Biobased-Polyethylene and Barley Thermomechanical Fibers: Micromechanics of Composites

by Ferran Serra-Parareda, Quim Tarrés, Marc Delgado-Aguilar, Francesc X. Espinach, Pere Mutjé and Fabiola Vilaseca

Materials 2019, 12(24), 4182; https://doi.org/10.3390/ma12244182 - 12 Dec 2019

Cited by 26 | Viewed by 2558

Abstract

The cultivation of cereals like rye, barley, oats, or wheat generates large quantities of agroforestry residues, which reaches values of around 2066 million metric tons/year. Barley straw alone represents 53%. In this work, barley straw is recommended for the production of composite materials in order to add value to this agricultural waste. First of all, thermomechanical (TMP) fibers from barley straw are produced and later used to reinforce bio-polyethylene (BioPE) matrix. TMP barley fibers were chemically and morphologically characterized. Later, composites with optimal amounts of coupling agent and fiber content ranging from 15 to 45 wt % were prepared. The mechanical results showed the strengthening and stiffening capacity of the TMP barley fibers. Finally, a micromechanical analysis is applied to evaluate the quality of the interface and to distinguish how the interface and the fiber morphology contributes to the final properties of these composite materials. Full article

(This article belongs to the Special Issue Environmentally Friendly Polymeric Blends from Renewable Sources)

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15 pages, 4798 KiB

Open AccessArticle

Radiation Synthesis of Pentaethylene Hexamine Functionalized Cotton Linter for Effective Removal of Phosphate: Batch and Dynamic Flow Mode Studies

by Jifu Du, Zhen Dong, Zhiyuan Lin, Xin Yang and Long Zhao

Materials 2019, 12(20), 3393; https://doi.org/10.3390/ma12203393 - 17 Oct 2019

Cited by 10 | Viewed by 2089

Abstract

A quaternized cotton linter fiber (QCLF) based adsorbent for removal of phosphate was prepared by grafting glycidyl methacrylate onto cotton linter and subsequent ring-opening reaction of epoxy groups and further quaternization. The adsorption behavior of the QCLF for phosphate was evaluated in a batch and column experiment. The batch experiment demonstrated that the adsorption process followed pseudo-second-order kinetics with an R² value of 0.9967, and the Langmuir model with R² value of 0.9952. The theoretical maximum adsorption capacity reached 152.44 mg/g. The experimental data of the fixed-bed column were well fitted with the Thomas and Yoon–Nelson models, and the adsorption capacity of phosphate at 100 mg/L and flow rate 1 mL/min reached 141.58 mg/g. The saturated QCLF could be regenerated by eluting with 1 M HCl. Full article

(This article belongs to the Special Issue Environmentally Friendly Polymeric Blends from Renewable Sources)

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14 pages, 1360 KiB

Open AccessArticle

The Influence of Lignin Diversity on the Structural and Thermal Properties of Polymeric Microspheres Derived from Lignin, Styrene, and/or Divinylbenzene

by Marta Goliszek, Beata Podkościelna, Olena Sevastyanova, Barbara Gawdzik and Artur Chabros

Materials 2019, 12(18), 2847; https://doi.org/10.3390/ma12182847 - 4 Sep 2019

Cited by 6 | Viewed by 2532

Abstract

This work investigates the impact of lignin origin and structural characteristics, such as molecular weight and functionality, on the properties of corresponding porous biopolymeric microspheres obtained through suspension-emulsion polymerization of lignin with styrene (St) and/or divinylbenzene (DVB). Two types of kraft lignin, which are softwood (Picea abies L.) and hardwood (Eucalyptus grandis), fractionated by common industrial solvents, and related methacrylates, were used in the synthesis. The presence of the appropriate functional groups in the lignins and in the corresponding microspheres were investigated by attenuated total reflectance Fourier transform infrared spectroscopy (ATR/FT-IR), while the thermal properties were studied by differential scanning calorimetry (DSC). The texture of the microspheres was characterized using low-temperature nitrogen adsorption. The swelling studies were performed in typical organic solvents and distilled water. The shapes of the microspheres were confirmed with an optical microscope. The introduction of lignin into a St and/or DVB polymeric system made it possible to obtain highly porous functionalized microspheres that increase their sorption potential. Lignin methacrylates created a polymer network with St and DVB, whereas the unmodified lignin acted mainly as an eco-friendly filler in the pores of St-DVB or DVB microspheres. The incorporation of biopolymer into the microspheres could be a promising alternative to a modification of synthetic materials and a better utilization of lignin. Full article

(This article belongs to the Special Issue Environmentally Friendly Polymeric Blends from Renewable Sources)

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