Environment-Friendly Polymers: Synthesis, Processing and Applications (2nd Edition)

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

Deadline for manuscript submissions: 31 July 2024 | Viewed by 5981

Special Issue Editor


E-Mail Website
Guest Editor
Department of Engineering for Innovation, University of Salento, 73100 Lecce, Italy
Interests: bio-based thermoplastics and thermosets; synthesis of bio-precursors; thermal analysis; rheology; plasticization; recycling
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

In recent years, growing environmental awareness has motivated researchers from the industry and academia to replace petroleum-derived polymers and additives with bioplastics by developing environmentally friendly thermoplastic polymers from bio-based and biodegradable raw materials. The use of petroleum-based raw materials to start the synthesis of monomers and thermoset matrices, often used to produce composites, is a significant limitation. The synthesis of bio-based monomers involves using natural sources, such as vegetable oils, natural acids, lignin, and so forth. Recently, innovative feedstocks obtained from food scraps, algae biomass, and industrial or municipal waste have been used for producing biopolymers, thus allowing waste to be valorised. Additionally, new procedures that synthesize precursors from natural renewable resources have aimed to decrease or remove the use of organic solvents, thus developing an authentic green approach.

Hence, polymers obtained from renewable resources are becoming increasingly significant as highly sustainable, eco-efficient, and biodegradable products. Due to their quick rate of development, bio-based polymers are expected to appear in commodity applications in the near future.

This Special Issue investigates synthesis, processing, and applications in bio-based polymers. Both original contributions and comprehensive reviews are welcome. Potential topics include but are not limited to the following:

  • The synthesis of bio-polymers;
  • The classification of raw material and waste valorisation;
  • An analysis of bio-polymers;
  • The physics of bio-based polymers;
  • Processing and performances of bio-based polymers;
  • The additive manufacturing of bio-based materials;
  • The biodegradability of polymeric materials;
  • Bio-composites;
  • The recycling of bio-based thermoplastics and thermosets;
  • Bio-based additives for polymers.

Dr. Francesca Ferrari
Guest Editor

Manuscript Submission Information

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. Polymers 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 2700 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

  • bio-based polymers
  • waste valorisation
  • synthesis, physics, and analysis of the bio-polymer
  • bio-based composites
  • additive manufacturing of bio-polymers
  • recycling strategies of bio-thermoplastics and bio-thermosets
  • application of bio-based polymeric materials

Related Special Issue

Published Papers (6 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Jump to: Review

13 pages, 9648 KiB  
Article
Preparation and Structural Analysis of a Water-Soluble Aminated Lignin
by Qi Zheng, Guangzai Nong and Ning Li
Polymers 2024, 16(9), 1237; https://doi.org/10.3390/polym16091237 - 28 Apr 2024
Viewed by 518
Abstract
Lignin is insoluble in water, thereby limiting its use in the synthesis of adhesives. Therefore, in this study, an aminated lignin compound was prepared through a lignin amination reaction to increase the amount of raw lignin material that can be used in the [...] Read more.
Lignin is insoluble in water, thereby limiting its use in the synthesis of adhesives. Therefore, in this study, an aminated lignin compound was prepared through a lignin amination reaction to increase the amount of raw lignin material that can be used in the synthesis of adhesives; moreover, structural analysis was conducted. The main result of this was the introduction of amino groups into phenolic hydroxyl groups in the hydrolyzing lignin from the raw lignin materials, thus generating the product of aminated lignin. The resulting particle sizes were about 100 nm, the average molecular weight was 57,627 g/mol, and the water solubility of the aminated lignin was about 0.45 g/100 mL. Therefore, the water solubility of raw lignin was greatly improved. The proposed reaction mechanism of phenolic hydroxyl groups and carboxylic acid groups in lignin is a reaction with ammonia molecules; thus, the successful introduction of amino groups generated the aminated lignin compounds. Hence, this article enriches the scientific theory of lignin reactions and provides a reference for the widespread application of raw lignin materials in the field of adhesives. Full article
Show Figures

Figure 1

13 pages, 2735 KiB  
Article
Biodegradable UV-Protective Composite Film from Cellulosic Waste: Utilisation of Cotton Gin Motes as Biocomponent
by Zengxiao Cai, Abu Naser Md Ahsanul Haque, Renuka Dhandapani and Maryam Naebe
Polymers 2024, 16(1), 88; https://doi.org/10.3390/polym16010088 - 27 Dec 2023
Viewed by 741
Abstract
With an increase in environmental pollution and microplastic problems, it is more urgent now to replace non-biodegradable films with biodegradable films that are low-cost and from renewable resources. Cotton gin motes (GM), a type of cellulosic waste that is generated from cotton ginning, [...] Read more.
With an increase in environmental pollution and microplastic problems, it is more urgent now to replace non-biodegradable films with biodegradable films that are low-cost and from renewable resources. Cotton gin motes (GM), a type of cellulosic waste that is generated from cotton ginning, is an excellent candidate for fabricating biodegradable films due to its properties and abundance. In this study, GM was first mechanically milled into a fine powder, followed by compounding with polycaprolactone (PCL) and extruded to produce composite pellets which were then compress-moulded into composite films. This environmentally friendly process used physical processing and all the materials were consumed in the process without generating any waste residue. To improve the compatibility and mixing properties between GM and PCL, the use of a plasticiser (polyethylene glycol) was considered. A high content of GM powder (up to 50%) was successfully compounded with the polymer. The SEM images of the composite films showed smooth surface morphology and well-distributed GM powder in the PCL matrix. The added advantage of compounding GM with the polymer matrix was that the composite film developed UV-shielding properties due to the presence of lignin in the GM powder. This property will be critical for films used in UV-resistance applications. Furthermore, the composite even with high GM content (50%), showed good mechanical properties, with 9.5 MPa yield strength and 442% elongation, which was only a 50% decrease in elongation when compared with clear PCL film. The soil biodegradation of GM composite films under controlled temperature (20 °C) and humidity (50%) for 1 month showed around 41% weight loss. Overall, this study demonstrates the potential of GM to be used as a biodegradable and UV-protective composite film for a wide array of applications, such as packaging and UV-protective coverings. Full article
Show Figures

Figure 1

18 pages, 8432 KiB  
Article
Cheminformatics-Based Design and Synthesis of Hydroxyapatite/Collagen Nanocomposites for Biomedical Applications
by Mohamed Aaddouz, Khalil Azzaoui, Rachid Sabbahi, Moulay Hfid Youssoufi, Meryem Idrissi Yahyaoui, Abdeslam Asehraou, Mohamed El Miz, Belkheir Hammouti, Sergey Shityakov, Mohamed Siaj and Elmiloud Mejdoubi
Polymers 2024, 16(1), 85; https://doi.org/10.3390/polym16010085 - 27 Dec 2023
Viewed by 1020
Abstract
This paper presents a novel cheminformatics approach for the design and synthesis of hydroxyapatite/collagen nanocomposites, which have potential biomedical applications in tissue engineering, drug delivery, and orthopedic and dental implants. The nanocomposites are synthesized by the co-precipitation method with different ratios of hydroxyapatite [...] Read more.
This paper presents a novel cheminformatics approach for the design and synthesis of hydroxyapatite/collagen nanocomposites, which have potential biomedical applications in tissue engineering, drug delivery, and orthopedic and dental implants. The nanocomposites are synthesized by the co-precipitation method with different ratios of hydroxyapatite and collagen. Their mechanical, biological, and degradation properties are analyzed using various experimental and computational techniques. Attenuated total reflection–Fourier-transform infrared spectroscopy, thermogravimetric analysis, and X-ray diffraction unveil the low crystallinity and nanoscale particle size of hydroxyapatite (22.62 nm) and hydroxyapatite/collagen composites (14.81 nm). These findings are substantiated by scanning electron microscopy with energy-dispersive X-ray spectroscopy, confirming the Ca/P ratio between 1.65 and 1.53 and attesting to the formation of non-stoichiometric apatites in all samples, further validated by molecular simulation. The antimicrobial activity of the nanocomposites is evaluated in vitro against several bacterial and fungal strains, demonstrating their medical potential. Additionally, in silico analyses are performed to predict the absorption, distribution, metabolism, and excretion properties and the bioavailability of the collagen samples. This study paves the way for the development of novel biomaterials using chemoinformatics tools and methods, facilitating the optimization of design and synthesis parameters, as well as the prediction of biological outcomes. Future research directions should encompass the investigation of in vivo biocompatibility and bioactivity of the nanocomposites, while exploring further applications and functionalities of these innovative materials. Full article
Show Figures

Figure 1

13 pages, 2999 KiB  
Article
Antibacterial Gelatin Composite Hydrogels Comprised of In Situ Formed Zinc Oxide Nanoparticles
by Ya-Chu Yu, Ming-Hsien Hu, Hui-Zhong Zhuang, Thi Ha My Phan, Yi-Sheng Jiang and Jeng-Shiung Jan
Polymers 2023, 15(19), 3978; https://doi.org/10.3390/polym15193978 - 3 Oct 2023
Cited by 1 | Viewed by 1063
Abstract
We report the feasibility of using gelatin hydrogel networks as the host for the in situ, environmentally friendly formation of well-dispersed zinc oxide nanoparticles (ZnONPs) and the evaluation of the antibacterial activity of the as-prepared composite hydrogels. The resulting composite hydrogels displayed remarkable [...] Read more.
We report the feasibility of using gelatin hydrogel networks as the host for the in situ, environmentally friendly formation of well-dispersed zinc oxide nanoparticles (ZnONPs) and the evaluation of the antibacterial activity of the as-prepared composite hydrogels. The resulting composite hydrogels displayed remarkable biocompatibility and antibacterial activity as compared to those in previous studies, primarily attributed to the uniform distribution of the ZnONPs with sizes smaller than 15 nm within the hydrogel network. In addition, the composite hydrogels exhibited better thermal stability and mechanical properties as well as lower swelling ratios compared to the unloaded counterpart, which could be attributed to the non-covalent interactions between the in situ formed ZnONPs and polypeptide chains. The presence of ZnONPs contributed to the disruption of bacterial cell membranes, the alteration of DNA molecules, and the subsequent release of reactive oxygen species within the bacterial cells. This chain of events culminated in bacterial cell lysis and DNA fragmentation. This research underscores the potential benefits of incorporating antibacterial agents into hydrogels and highlights the significance of preparing antimicrobial agents within gel networks. Full article
Show Figures

Figure 1

Review

Jump to: Research

28 pages, 5649 KiB  
Review
Biopolymer Materials in Triboelectric Nanogenerators: A Review
by Qiliang Zhu, Enqi Sun, Zequan Zhao, Tong Wu, Shuchang Meng, Zimeng Ma, Muhammad Shoaib, Hafeez Ur Rehman, Xia Cao and Ning Wang
Polymers 2024, 16(10), 1304; https://doi.org/10.3390/polym16101304 - 7 May 2024
Viewed by 438
Abstract
In advancing the transition of the energy sector toward heightened sustainability and environmental friendliness, biopolymers have emerged as key elements in the construction of triboelectric nanogenerators (TENGs) due to their renewable sources and excellent biodegradability. The development of these TENG devices is of [...] Read more.
In advancing the transition of the energy sector toward heightened sustainability and environmental friendliness, biopolymers have emerged as key elements in the construction of triboelectric nanogenerators (TENGs) due to their renewable sources and excellent biodegradability. The development of these TENG devices is of significant importance to the next generation of renewable and sustainable energy technologies based on carbon-neutral materials. This paper introduces the working principles, material sources, and wide-ranging applications of biopolymer-based triboelectric nanogenerators (BP-TENGs). It focuses on the various categories of biopolymers, ranging from natural sources to microbial and chemical synthesis, showcasing their significant potential in enhancing TENG performance and expanding their application scope, while emphasizing their notable advantages in biocompatibility and environmental sustainability. To gain deeper insights into future trends, we discuss the practical applications of BP-TENG in different fields, categorizing them into energy harvesting, healthcare, and environmental monitoring. Finally, the paper reveals the shortcomings, challenges, and possible solutions of BP-TENG, aiming to promote the advancement and application of biopolymer-based TENG technology. We hope this review will inspire the further development of BP-TENG towards more efficient energy conversion and broader applications. Full article
Show Figures

Figure 1

18 pages, 1395 KiB  
Review
Biocomposites of Cellulose Isolated from Coffee Processing By-Products and Incorporation in Poly(Butylene Adipate-Co-Terephthalate) (PBAT) Matrix: An Overview
by Fernanda Fabbri Gondim, João Gabriel Passos Rodrigues, Vinicius Oliveira Aguiar, Maria de Fátima Vieira Marques and Sergio Neves Monteiro
Polymers 2024, 16(3), 314; https://doi.org/10.3390/polym16030314 - 24 Jan 2024
Viewed by 1286
Abstract
With its extensive production and consumption, the coffee industry generates significant amounts of lignocellulosic waste. This waste, primarily comprising coffee biomasses, is a potential source of cellulose. This cellulose can be extracted and utilized as a reinforcing agent in various biocomposites with polymer [...] Read more.
With its extensive production and consumption, the coffee industry generates significant amounts of lignocellulosic waste. This waste, primarily comprising coffee biomasses, is a potential source of cellulose. This cellulose can be extracted and utilized as a reinforcing agent in various biocomposites with polymer matrices, thereby creating high-value products. One such biodegradable polymer, Poly(butylene adipate-co-terephthalate) (PBAT), is notable for its properties that are comparable with low-density polyethylene, making it an excellent candidate for packaging applications. However, the wider adoption of PBAT is hindered by its relatively high cost and lower thermomechanical properties compared with conventional, non-biodegradable polymers. By reinforcing PBAT-based biocomposites with cellulose, it is possible to enhance their thermomechanical strength, as well as improve their water vapor and oxygen barrier capabilities, surpassing those of pure PBAT. Consequently, this study aims to provide a comprehensive review of the latest processing techniques for deriving cellulose from the coffee industry’s lignocellulosic by-products and other coffee-related agro-industrial wastes. It also focuses on the preparation and characterization of cellulose-reinforced PBAT biocomposites. Full article
Show Figures

Figure 1

Back to TopTop