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1
Contreras Ramírez, Jesús Miguel, Dimas Alejandro Medina e Meribary Monsalve. "Poliésteres como Biomateriales. Una Revisión". Revista Bases de la Ciencia. e-ISSN 2588-0764 6, n. 2 (30 agosto 2021): 113. http://dx.doi.org/10.33936/rev_bas_de_la_ciencia.v6i2.3156.
Testo completoAbstract (sommario):
Los materiales biodegradables se utilizan en envases, agricultura, medicina y otras áreas. Para proporcionar resultados eficientes, cada una de estas aplicaciones demanda materiales con propiedades físicas, químicas, biológicas, biomecánicas y de degradación específicas. Dado que, durante el proceso de síntesis de los poliésteres todas estas propiedades pueden ser ajustadas, estos polímeros representan excelentes candidatos como materiales sintéticos biodegradables y bioabsorbibles para todas estas aplicaciones. La siguiente revisión presenta una visión general de los diferentes poliésteres biodegradables que se están utilizando actualmente y sus propiedades, así como nuevos desarrollos en su síntesis y aplicaciones.
Palabra clave: biomateriales, polímeros biodegradables, poliésteres, policarbonatos, biopolímeros.
Abstract
Biodegradable materials are used in packaging, agriculture, medicine, and many other areas. These applications demand materials with specific physical, chemical, biological, biomechanical, and degradation properties to provide efficient results. Since all these properties can be adjusted during the polyesters synthesis process, these polymers represent excellent candidates as biodegradable and bio-absorbable synthetic materials for all these applications. Here, in this review is presented an overview of the different biodegradable polyesters currently used, their properties, and new developments in their synthesis and applications.
Keywords: biomaterials, biodegradable polymers, polyesters, polycarbonates, biopolymers.
2
Lang, Kening, Regina J. Sánchez-Leija, Richard A. Gross e Robert J. Linhardt. "Review on the Impact of Polyols on the Properties of Bio-Based Polyesters". Polymers 12, n. 12 (12 dicembre 2020): 2969. http://dx.doi.org/10.3390/polym12122969.
Testo completoAbstract (sommario):
Bio-based polyol polyesters are biodegradable elastomers having potential utility in soft tissue engineering. This class of polymers can serve a wide range of biomedical applications. Materials based on these polymers are inherently susceptible to degradation during the period of implantation. Factors that influence the physicochemical properties of polyol polyesters might be useful in achieving a balance between durability and biodegradability. The characterization of these polyol polyesters, together with recent comparative studies involving creative synthesis, mechanical testing, and degradation, have revealed many of their molecular-level differences. The impact of the polyol component on the properties of these bio-based polyesters and the optimal reaction conditions for their synthesis are only now beginning to be resolved. This review describes our current understanding of polyol polyester structural properties as well as a discussion of the more commonly used polyol monomers.
3
Kopitzky, Rodion. "Poly(lactic acid)–Poly(butylene succinate)–Sugar Beet Pulp Composites; Part II: Water Absorption Characteristics with Fine and Coarse Sugar Beet Pulp Particles; A Phenomenological Investigation". Polymers 13, n. 20 (15 ottobre 2021): 3558. http://dx.doi.org/10.3390/polym13203558.
Testo completoAbstract (sommario):
Sugar beet pulp (SBP) is a residue available in large quantities from the sugar industry, and can serve as a cost-effective bio-based and biodegradable filler for fully bio-based compounds containing bio-based polyesters. The composition of SBP is characterized by an unusually high content of pectins, which are known as water-binding substances. Their molecular structure and the poor gelling properties, compared to other pectin sources, do not allow industrial use on a larger scale. However, good water absorption capacity can be advantageous for promoting plastics degradation or disintegration in the environment. In this study, we evaluated the water absorption capacity and processes of SBP-filled composites with bio-based polyesters on a longer time scale. We analyzed water absorption from a phenomenological point of view and tried to derive basic parameters for the general description of the composites behavior. We found that polar polyesters or polyester blends filled with higher amounts of especially coarse SBP suffer disintegration within a few weeks when supplied with sufficient water. On the other hand, less polar polyesters filled with fine SBP rather absorb water but do not show disintegration for several months. On a time scale of a few years, catalytic disintegration of the composites appears to be independent of the addition of SBP.
4
Berketova, L., e V. Polkovnikova. "On the Eco-, Edible and Fast-decomposing Packaging in the Food Industry". Bulletin of Science and Practice 6, n. 10 (15 ottobre 2020): 234–43. http://dx.doi.org/10.33619/2414-2948/59/23.
Testo completoAbstract (sommario):
At the moment, all economically developed countries face the problem of pollution of the surrounding world, and one of the main pollutants is packaging. Packaging helps to preserve its contents from various damages, and informative and attractive packaging is an indispensable attribute of the marketing process. Most products are Packed in a huge amount of film and paper, which is thrown out by the consumer to the landfill. As a result, there are growing landfills for garbage, 40 % of which is disposable packaging. In the conditions of increased demand for so-called healthy food products, the question of packaging this food in no less "healthy" packaging arose. Eco-friendly, biodegradable, and edible packaging is one of the relatively new trends in the field of ecology. The international standard ASTM D-6400 "Standard specification for marking plastics intended for aerobic composting in municipal or industrial facilities" regulates the development of bioplastic mass technologies. According to the Standard specification for compostable plastics, biodegradable and decomposable plastics are classified into the following groups: starch, cellulose and protein based plastics; aliphatic polyesters; polylactic acids; polytrihydroxybutyrate; polyhydroxalkanoates; bio-derived polyethylene and lipid-derived polymers. According to the method of decomposition, bioplastics are divided into compostable plastic and photo-degradable plastics. The range of biodegradable plastics includes: starch; natural polyesters; renewable resource polyesters; synthetic aliphatic polyesters; aliphatic-aromatic co-polyesters; hydro-biodegradable polyester; water-soluble polymers; photo-biodegradable plastics and controlled degradation of dietary supplements. In the Russian Federation, the issues of bioplastic production have not been developed and are not legally fixed. Today, the main types of edible packaging include natural casings for meat products, wafer cups for ice cream, craft paper, cardboard, wood, cellulose, and others. Jute bags are a potential biodegradable packaging material. Many companies produce modern disposable eco-friendly dishes made of wood, bamboo, carbonized bamboo, sugar cane and other eco-friendly materials without the use of chemicals.
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González-Arancibia, Fernanda, Maribel Mamani, Cristian Valdés, Caterina Contreras-Matté, Eric Pérez, Javier Aguilera, Victoria Rojas, Howard Ramirez-Malule e Rodrigo Andler. "Biopolymers as Sustainable and Active Packaging Materials: Fundamentals and Mechanisms of Antifungal Activities". Biomolecules 14, n. 10 (27 settembre 2024): 1224. http://dx.doi.org/10.3390/biom14101224.
Testo completoAbstract (sommario):
Developing bio-based and biodegradable materials has become important to meet current market demands, government regulations, and environmental concerns. The packaging industry, particularly for food and beverages, is known to be the world’s largest consumer of plastics. Therefore, the demand for sustainable alternatives in this area is needed to meet the industry’s requirements. This review presents the most commonly used bio-based and biodegradable packaging materials, bio-polyesters, and polysaccharide-based polymers. At the same time, a major problem in food packaging is presented: fungal growth and, consequently, food spoilage. Different types of antifungal compounds, both natural and synthetic, are explained in terms of structure and mechanism of action. The main uses of these antifungal compounds and their degree of effectiveness are detailed. State-of-the-art studies have shown a clear trend of increasing studies on incorporating antifungals in biodegradable materials since 2000. The bibliometric networks showed studies on active packaging, biodegradable polymers, films, antimicrobial and antifungal activities, essential oils, starch and polysaccharides, nanocomposites, and nanoparticles. The combination of the development of bio-based and biodegradable materials with the ability to control fungal growth promotes both sustainability and the innovative enhancement of the packaging sector.
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Kuru, Zehra, e Mehmet Arif Kaya. "Poly(Lactic Acid) / Polyester Blends: Review of Current and Future Applications". European Journal of Research and Development 3, n. 1 (28 marzo 2023): 175–99. http://dx.doi.org/10.56038/ejrnd.v3i1.259.
Testo completoAbstract (sommario):
Poly (lactic acid) (PLA) is a promising polymer with its value and potential due to its sustainability, low carbon footprint, and being a superior bio-based polymer compared to other bioplastics. Since it is also a compostable aliphatic polyester, has been frequently subjected to research.
Researchers have conducted studies on the compatibility of PLA, which is a bio-based, biodegradable, and compostable, renewable polymer, with traditional petrochemical-based polymers, especially polyesters such as polybutylene terephthalate (PBT), and polyethylene terephthalate (PET). It is highly important that applications of PLA/polyester blends will ensure that the materials developed are not only economically and sustainable but also can meet current and future appropriate needs. PLA-based materials have some disadvantages such as slow biodegradation rate, high cost, and low toughness, and to eliminate mentioned drawbacks generally blends are prepared with petroleum-based polymers.
In this review, information about the perspectives with studies for PLA/polyester blends; approaches to the subject, potential application areas, and contributions for the future were given.
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Todea, Anamaria, Emese Biro, Valentin Badea, Cristina Paul, Adinela Cimporescu, Lajos Nagy, Sándor Kéki, Geza Bandur, Carmen Boeriu e Francisc Péter. "Optimization of enzymatic ring-opening copolymerizations involving δ-gluconolactone as monomer by experimental design". Pure and Applied Chemistry 86, n. 11 (1 novembre 2014): 1781–92. http://dx.doi.org/10.1515/pac-2014-0717.
Testo completoAbstract (sommario):
Abstract Enzymatic incorporation of carbohydrate-derived monomer units into hydrophobic polyester backbones represents a promising alternative to obtain new biodegradable oligomers and polymers. Immobilized lipases are efficient biocatalysts for copolymerization of β-butyrolactone and δ-gluconolactone, but only a systematic optimization study was able to highlight the influence of the main reaction parameters on the polymerization degree and on the relative copolymer content of the product. Therefore, experimental design was employed for determination of the optimal ring-opening copolymerization conditions in solventless reaction systems, at temperatures up to 80 °C. The obtained products, cyclic and linear polyesters, have been characterized by FT-IR, MALDI-TOF MS, NMR, and TG analysis, demonstrating the incorporation of gluconolactone unit(s) into the hydrophobic backbone of the polyester and the formation of new bio-based products.
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Montava-Jorda, Sergi, Diego Lascano, Luis Quiles-Carrillo, Nestor Montanes, Teodomiro Boronat, Antonio Vicente Martinez-Sanz, Santiago Ferrandiz-Bou e Sergio Torres-Giner. "Mechanical Recycling of Partially Bio-Based and Recycled Polyethylene Terephthalate Blends by Reactive Extrusion with Poly(styrene-co-glycidyl methacrylate)". Polymers 12, n. 1 (9 gennaio 2020): 174. http://dx.doi.org/10.3390/polym12010174.
Testo completoAbstract (sommario):
In the present study, partially bio-based polyethylene terephthalate (bio-PET) was melt-mixed at 15–45 wt% with recycled polyethylene terephthalate (r-PET) obtained from remnants of the injection blowing process of contaminant-free food-use bottles. The resultant compounded materials were thereafter shaped into pieces by injection molding for characterization. Poly(styrene-co-glycidyl methacrylate) (PS-co-GMA) was added at 1–5 parts per hundred resin (phr) of polyester blend during the extrusion process to counteract the ductility and toughness reduction that occurred in the bio-PET pieces after the incorporation of r-PET. This random copolymer effectively acted as a chain extender in the polyester blend, resulting in injection-molded pieces with slightly higher mechanical resistance properties and nearly the same ductility and toughness than those of neat bio-PET. In particular, for the polyester blend containing 45 wt% of r-PET, elongation at break (εb) increased from 10.8% to 378.8% after the addition of 5 phr of PS-co-GMA, while impact strength also improved from 1.84 kJ·m−2 to 2.52 kJ·m−2. The mechanical enhancement attained was related to the formation of branched and larger macromolecules by a mechanism of chain extension based on the reaction of the multiple glycidyl methacrylate (GMA) groups present in PS-co-GMA with the hydroxyl (–OH) and carboxyl (–COOH) terminal groups of both bio-PET and r-PET. Furthermore, all the polyester blend pieces showed thermal and dimensional stabilities similar to those of neat bio-PET, remaining stable up to more than 400 °C. Therefore, the use low contents of the tested multi-functional copolymer can successfully restore the properties of bio-based but non-biodegradable polyesters during melt reprocessing with their recycled petrochemical counterparts and an effective mechanical recycling is achieved.
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Lucas, Francisco W. S., Yuval Fishler e Adam Holewinski. "Tuning the selectivity of electrochemical levulinic acid reduction to 4-hydroxyvaleric acid: a monomer for biocompatible and biodegradable plastics". Green Chemistry 23, n. 22 (2021): 9154–64. http://dx.doi.org/10.1039/d1gc02826j.
Testo completoAbstract (sommario):
Levulinic acid (LA) is a biomass-derived feedstock; herein, we present an efficient electrochemical method for converting LA into 4-hydroxyvaleric acid, a valuable monomer for bio-polyesters, as well as γ-valerolactone (a green fuel/solvent).
10
Dong, Weifu, Huiling Li, Mingqing Chen, Zhongbin Ni, Jishi Zhao, Haipeng Yang e Pieter Gijsman. "Biodegradable bio-based polyesters with controllable photo-crosslinkability, thermal and hydrolytic stability". Journal of Polymer Research 18, n. 6 (11 novembre 2010): 1239–47. http://dx.doi.org/10.1007/s10965-010-9526-x.
Testo completo
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Bi, Siwen, Vincenzo Barinelli e Margaret J. Sobkowicz. "Degradable Controlled Release Fertilizer Composite Prepared via Extrusion: Fabrication, Characterization, and Release Mechanisms". Polymers 12, n. 2 (2 febbraio 2020): 301. http://dx.doi.org/10.3390/polym12020301.
Testo completoAbstract (sommario):
In this work, biodegradable polymers were melt compounded with urea phosphate to fabricate “smart fertilizers” for sustainable agriculture. Urea phosphate (UP) is typically applied as a water-soluble fertilizer to treat phosphorus deficiency in high pH soils. Due to the low diffusion rate of phosphate through slow-release fertilizer coatings, phosphate supply has been considered the “bottleneck” for nitrogen–phosphorous–potassium (NPK) nutrients supply. We study the influence of polymer matrix structure on release kinetics in deionized water using novel polyesters including poly (hexamethylene succinate) (PHS), poly (30% butylene succinate-co-70% hexamethylene succinate) (PBHS 30/70), and PBHS 70/30. Melt processed composites of UP and polyester were analyzed to determine UP loading efficiency and dispersion and distribution of the salt in the polymer matrix. A combined empirical model involving diffusion and erosion mechanisms was found have a good agreement with the experimental release curve. This work provides a solution for environmentally friendly controlled release phosphate fertilizer with good release performance using bio-based and biodegradable polymers.
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Gkountela, Christina I., e Stamatina N. Vouyiouka. "Enzymatic Polymerization as a Green Approach to Synthesizing Bio-Based Polyesters". Macromol 2, n. 1 (24 gennaio 2022): 30–57. http://dx.doi.org/10.3390/macromol2010003.
Testo completoAbstract (sommario):
Given the fossil fuel crisis and the steady consumption of finite resources, the use of green polymers is becoming necessary. However, the term “green” describes materials that present green properties (such as biological origin and/or biodegradability) and are produced via sustainable processes conducted under mild conditions and not requiring the use of chemical catalysts, toxic solvents or reagents. Truly green materials must combine these characteristics; consequently, enzymatically synthesized bio-based and/or biodegradable polymers can be characterized as truly green. The present review focuses on the most promising, commercially available aliphatic and alipharomatic polyesters that can be synthesized enzymatically. In particular, the recent developments in the enzymatic polymerization of PLA and PBS and alipharomatic furan-based polyesters (e.g., PBF) are herein analyzed. Based on this analysis, it can be concluded that important steps have been taken toward synthesizing sustainably green polymers. Still, it is necessary to evaluate the applied methods regarding their capability to be used on an industrial scale.
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Govindan, Srinivasan, Maximiano Ramos e Ahmed M. Al-Jumaily. "A Review of Biodegradable Polymer Blends and Polymer Composite for Flexible Food Packaging Application". Materials Science Forum 1094 (27 luglio 2023): 51–60. http://dx.doi.org/10.4028/p-dc7wkh.
Testo completoAbstract (sommario):
The introduction of plastic materials has revolutionised our society. However, excessive use of traditional, non-biodegradable plastic materials, especially for packaging applications, has created many environmental issues. During the past few decades, many biodegradable polymers, bio-based and petroleum-based, have been developed to address the above problem. Several research has been carried out on various biodegradable polymer blends and composites. However, their widespread application is still limited. This paper gives an overview and progress made on biodegradable polymers for flexible packaging applications, a critical analysis of their performance characteristics and recommendations on priority areas for further research. This Paper shows that, among the polyesters, though PHAs is most attractive concerning biodegradability, its low elongation at break, narrow processing temperature and high production cost limit their use for flexible packaging application. For flexible packaging applications, PBS (Polybutylene succinate) is better than PLA (Polylactic acid) and PHAs (Polyhydroxyalkonates), considering thermal characteristics and tensile elongation. In addition, PBS is biodegradable in compost, soil, lake and seawater, though its rate of biodegradation is reported to be slower compared to PHAs.
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Rosato, Antonella, Angela Romano, Grazia Totaro, Annamaria Celli, Fabio Fava, Giulio Zanaroli e Laura Sisti. "Enzymatic Degradation of the Most Common Aliphatic Bio-Polyesters and Evaluation of the Mechanisms Involved: An Extended Study". Polymers 14, n. 9 (30 aprile 2022): 1850. http://dx.doi.org/10.3390/polym14091850.
Testo completoAbstract (sommario):
Commercial hydrolytic enzymes belonging to different subclasses (several lipases, proteinase k, cutinase) were investigated for their ability to degrade different aliphatic polyesters, i.e., poly(butylene succinate) (PBS), poly(butylene succinate-co-adipate) (PBSA), two poly(caprolactone), having two different molecular weights, poly(lactic acid) (PLA) and poly(propylene carbonate) (PPC). The enzyme screening was first carried out by investigating the capacity of fully degrading the target polymers in 24 h, then weight loss measurements of selected polyesters and target enzymes were performed. Solid residues after enzyme degradation were characterized by proton nuclear magnetic resonance (1H NMR), gel permeation chromatography (GPC), infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC) and thermogravimetry (TGA). Liquid fractions were studied via GPC, 1H NMR and high-performance liquid chromatography (HPLC). PCL and PBSA were found to be the most biodegradable polyesters, under the conditions used in this study. PBS was fully degraded only by cutinase, whereas none of the tested enzymes were able to completely degrade PLA and PPC, in the conditions assessed here. Cutinase exhibited the highest hydrolytic activity on PBSA, while lipase from Candida sp. (CALB) on low molecular weight PCL. Chemical analyses on residual solids showed that the enzymatic degradation occurred homogeneously from the surface through an erosion mechanism and did not significantly affect the macromolecular structure and thermal stability. Cleaving action mode for each enzyme (endo- and/or exo-type) on the different polyesters were also proposed based on the evaluation of the degradation products in the liquid fraction.
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David, Grégoire, Nathalie Gontard e Hélène Angellier-Coussy. "Mitigating the Impact of Cellulose Particles on the Performance of Biopolyester-Based Composites by Gas-Phase Esterification". Polymers 11, n. 2 (24 gennaio 2019): 200. http://dx.doi.org/10.3390/polym11020200.
Testo completoAbstract (sommario):
Materials that are both biodegradable and bio-sourced are becoming serious candidates for substituting traditional petro-sourced plastics that accumulate in natural systems. New biocomposites have been produced by melt extrusion, using bacterial polyester (poly(3-hydroxybutyrate-co-3-hydroxyvalerate)) as a matrix and cellulose particles as fillers. In this study, gas-phase esterified cellulose particles, with palmitoyl chloride, were used to improve filler-matrix compatibility and reduce moisture sensitivity. Structural analysis demonstrated that intrinsic properties of the polymer matrix (crystallinity, and molecular weight) were not more significantly affected by the incorporation of cellulose, either virgin or grafted. Only a little decrease in matrix thermal stability was noticed, this being limited by cellulose grafting. Gas-phase esterification of cellulose improved the filler’s dispersion state and filler/matrix interfacial adhesion, as shown by SEM cross-section observations, and limiting the degradation of tensile properties (stress and strain at break). Water vapor permeability, moisture, and liquid water uptake of biocomposites were increased compared to the neat matrix. The increase in thermodynamic parameters was limited in the case of grafted cellulose, principally ascribed to their increased hydrophobicity. However, no significant effect of grafting was noticed regarding diffusion parameters.
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Jacquel, Nicolas, René Saint-Loup, Jean-Pierre Pascault, Alain Rousseau e Françoise Fenouillot. "Bio-based alternatives in the synthesis of aliphatic–aromatic polyesters dedicated to biodegradable film applications". Polymer 59 (febbraio 2015): 234–42. http://dx.doi.org/10.1016/j.polymer.2014.12.021.
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Hajdek, Krunoslav, Bozo Smoljan, Bojan Sarkanj e Wojciech Sitek. "PROCESSING TECHNOLOGIES, PROPERTIES AND APPLICATION OF POLY (LACTIC ACID) (PLA)". International Journal of Modern Manufacturing Technologies 15, n. 1 (20 giugno 2023): 87–97. http://dx.doi.org/10.54684/ijmmt.2023.15.1.87.
Testo completoAbstract (sommario):
Poly (lactic acid) (PLA) is a one of substitutions to fossil-based polymers because they have a less influence on the environment. Material sustainability requirements have increased importance of PLA polymers and others similar biopolymers. PLA polymeris an aliphatic polyester, usually produced by ring-opening polymerization or by polycondensation of lactic acid. For the production of PLA components, melt processing is one of the most commonly used techniques. Today, processing technologies of PLA components include injection moulding, hot pressing, spinning, blow moulding, foam moulding, electrospinning, 3D printing, and so on. PLA polymers have better thermal workability than most bio-based polymers. The analysis of mechanical properties, structure in processes, and an appropriate application of PLA is done in this paper. Also this paper summarizes variations in thermal degradation, recyclability, biodegradation and aging during PLA processing and application. The tensile strength and modulus of elasticity of PLA polymers is similar to those of conventional polyesters. But, because PLA polymers are biodegradable, they can change properties if exposed to uncontrolled temperature and humidity conditions. PLA polymers have lower toughness than those of conventional polyesters. Toughness could be improved by development of PLA composites. PLA is safe for use in the manufacturing of products that are in contact with food. European Food Safety Authority (EFSA) recognize PLA as material which can be safely employed as a food packaging material without causing adverse health effects. PLA possesses barrier properties that are just as effective as LDPE and PS. Limited antibacterial properties of PLA can be improved by application of antibacterial agents. Generally high price of PLA polymers limits their application as a packaging material. Biodegradable PLA polymers are suitable for a wide range of industrial, biomedical and pharmaceutical applications, such as material for medical implants, resorbable prostheses, controlled drug release, biodegradable joints and supports for tissue engineering. Development of processing methods is needed for sufficient increase the industrial application of PLA polymers. Suitable methods to minimize the disadvantages of PLA can be blending PLA with other materials, creating micro- and nanocomposites, coating with high-barrier materials, and polymer modification.
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Niu, Ruixue, Zhening Zheng, Xuedong Lv, Benqiao He, Sheng Chen, Jiaying Zhang, Yanhong Ji, Yi Liu e Liuchun Zheng. "Long-Chain Branched Bio-Based Poly(butylene dodecanedioate) Copolyester Using Pentaerythritol as Branching Agent: Synthesis, Thermo-Mechanical, and Rheological Properties". Polymers 15, n. 15 (26 luglio 2023): 3168. http://dx.doi.org/10.3390/polym15153168.
Testo completoAbstract (sommario):
The introduction of long-chain branched structures into biodegradable polyesters can effectively improve the melt strength and blow-molding properties of polyesters. In this study, pentaerythritol (PER) was used as a branching agent to synthesize branched poly(butylene dodecanedioate) (PBD), and the resulting polymers were characterized by Nuclear Magnetic Resonance Proton Spectra (1H NMR) and Fourier Transform Infrared spectroscopy (FT-IR). It was found that the introduction of a small amount of PER (0.25–0.5 mol%) can generate branching and even crosslinking structures. Both impact strength and tensile modulus can be greatly improved by the introduction of a branching agent. With the introduction of 1 mol% PER content in PBD, the notched impact strength of PBD has been increased by 85%, and the tensile modulus has been increased by 206%. Wide-angle X-ray diffraction and differential scanning calorimetry results showed that PER-branched PBDs exhibited improved crystallization ability compared with linear PBDs. Dynamic viscoelastics revealed that shear-thickening behaviors can be found for all branched PBD under low shear rates.
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Lajarrige, Anaïs, Nathalie Gontard, Sébastien Gaucel e Stéphane Peyron. "Evaluation of the Food Contact Suitability of Aged Bio-Nanocomposite Materials Dedicated to Food Packaging Applications". Applied Sciences 10, n. 3 (28 gennaio 2020): 877. http://dx.doi.org/10.3390/app10030877.
Testo completoAbstract (sommario):
Nanocomposite materials based on bio-polyesters (PBSA and PHBV) have been evaluated for their suitability for food contact according to the recommendations defined for non-biodegradable plastic materials, and subsequently, according to accelerated aging treatment. On the basis of the limited number of material/migrant/food simulant combinations studied here, the test for migration, using food simulants, appeared directly applicable to testing such materials which are not considered humidity-sensitive materials. Considering the only compliance criterion that must be met by the materials in contact, the materials submitted to the aging processing are not of safety concern and the incorporation of nanoclays in aged biodegradable materials does not interfere with their inertial properties in a dramatic way. At the molecular scale, the UV irradiation proved to induce an increase in the degree of crystallinity, resulting in a modification of transport properties of both packaging materials. The values of overall migration and specific migration were reduced without decreasing the diffusion coefficients of the target additives. The UV treatment and the addition of nanoparticles, therefore, seem to jointly promote the retention of organic compounds in the materials by increasing their affinity for packaging material.
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Gao, Chuanhui, Jing Zhang, Di Zhang, Yajie Dong, Sikai Wang, Jincheng Peng e Yuetao Liu. "Synthesis of bio-based waterborne polyesters as environmentally benign biodegradable material through regulation of unsaturated acid structure". European Polymer Journal 156 (agosto 2021): 110632. http://dx.doi.org/10.1016/j.eurpolymj.2021.110632.
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Kreetachat, Torpong, Jittiporn Kruenate e Kowit Suwannahong. "Preparation of TiO2/Bio-Composite Film by Sol-Gel Method in VOCs Photocatalytic Degradation Process". Applied Mechanics and Materials 390 (agosto 2013): 552–56. http://dx.doi.org/10.4028/www.scientific.net/amm.390.552.
Testo completoAbstract (sommario):
Biodegradable of polylactic acid (PLA), polybutylene adipate-co-terephthalate (PBAT) and polybutylene succinate (PBS), which were biodegradable aliphatic polyesters, composite films were contained with titanium dioxide (TiO2) as a photocatalyst to evaluate the photocatalytic activity of bidegradable composite films for toluene removal. The synthesized TiO2 was prepared by sol-gel method between titanium isopropoxide with acetic acid. To form the anatase structure, it was calcined at 500°C. TiO2 were added to PLA/PBAT/PBS as a biopolymer blend at 0, 5 and 10 wt% .The TiO2/Bio-composite films were fabricated via blown film technique to produce 40 μm films. Photocatalytic activity efficiency of TiO2/Bio-composite films was performed in an annular closed system under UV light. Since the amount of TiO2 affected the efficiency of the photocatalytic activity, this work was mainly concentrated on the effort to embed the high amount of TiO2 in the biopolymer matrix. The developed photocatalyst was characterized by XRD, UV-Vis spectrophotometer and SEM. The SEM images revealed the high homogeneity of the deposition of TiO2 on the biopolymer matrix. The X-ray diffraction (XRD) ensures the deposition of TiO2 as crystalline anatase phase. In addition, the photocatalytic results shown that the toluene removal efficiencies increased with an increasing TiO2 dosages at 0 wt%, 5 wt%, and 10 wt% , respectively. As aspects, the photocatalytic degradation results showed the highest tolune photocatalytic degradation efficiency of 52.0% at 10 wt% TiO2 .
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Olejnik, Olga, Anna Masek e Adam Kiersnowski. "Thermal Analysis of Aliphatic Polyester Blends with Natural Antioxidants". Polymers 12, n. 1 (2 gennaio 2020): 74. http://dx.doi.org/10.3390/polym12010074.
Testo completoAbstract (sommario):
The aim of this research was to enhance thermal stability of aliphatic polyester blends via incorporation of selected natural antioxidants of plant origin. Thermal methods of analysis, including differential scanning calorimetry (DSC) and thermogravimetry (TGA), are significant tools for estimating the stabilization effect of polyphenols in a polymer matrix. Thermal stability was determined by analyzing thermogravimetric curves. Polymers with selected antioxidants degraded more slowly with rising temperature in comparison to reference samples without additives. This property was also confirmed by results obtained from differential scanning calorimetry (DSC), where the difference between the oxidation temperatures of pure material and polymer with natural stabilizers was observed. According to the results, the materials with selected antioxidants, including trans-chalcone, flavone and lignin have higher oxidation temperature than the pure ones, which confirms that chosen phytochemicals protect polymers from oxidation. Moreover, based on the colour change results or FT-IR spectra analysis, some of the selected antioxidants, including lignin and trans-chalcone, can be utilized as colorants or aging indicators. Taking into account the data obtained, naturally occurring antioxidants, including polyphenols, can be applied as versatile pro-ecological additives for biodegradable and bio-based aliphatic polyesters to obtain fully environmentally friendly materials dedicated for packaging industry.
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Koller, Martin. "Switching from petro-plastics to microbial polyhydroxyalkanoates (PHA): the biotechnological escape route of choice out of the plastic predicament?" EuroBiotech Journal 3, n. 1 (1 gennaio 2019): 32–44. http://dx.doi.org/10.2478/ebtj-2019-0004.
Testo completoAbstract (sommario):
Abstract The benefit of biodegradable “green plastics” over established synthetic plastics from petro-chemistry, namely their complete degradation and safe disposal, makes them attractive for use in various fields, including agriculture, food packaging, and the biomedical and pharmaceutical sector. In this context, microbial polyhydroxyalkanoates (PHA) are auspicious biodegradable plastic-like polyesters that are considered to exert less environmental burden if compared to polymers derived from fossil resources. The question of environmental and economic superiority of bio-plastics has inspired innumerable scientists during the last decades. As a matter of fact, bio-plastics like PHA have inherent economic drawbacks compared to plastics from fossil resources; they typically have higher raw material costs, and the processes are of lower productivity and are often still in the infancy of their technical development. This explains that it is no trivial task to get down the advantage of fossil-based competitors on the plastic market. Therefore, the market success of biopolymers like PHA requires R&D progress at all stages of the production chain in order to compensate for this disadvantage, especially as long as fossil resources are still available at an ecologically unjustifiable price as it does today. Ecological performance is, although a logical argument for biopolymers in general, not sufficient to make industry and the society switch from established plastics to bio-alternatives. On the one hand, the review highlights that there’s indeed an urgent necessity to switch to such alternatives; on the other hand, it demonstrates the individual stages of the production chain, which need to be addressed to make PHA competitive in economic, environmental, ethical, and performance-related terms. In addition, it is demonstrated how new, smart PHA-based materials can be designed, which meet the customer’s expectations when applied, e.g., in the biomedical or food packaging sector.
24
Wyrębiak, Oledzka, Figat e Sobczak. "Application of Diethylzinc/propyl Gallate Catalytic System for Ring-Opening Copolymerization of rac-Lactide and ε-Caprolactone". Molecules 24, n. 22 (17 novembre 2019): 4168. http://dx.doi.org/10.3390/molecules24224168.
Testo completoAbstract (sommario):
Biodegradable polyesters gain significant attention because of their wide potential biomedical applications. The ring-opening polymerization method is widely used to obtain such polymers, due to high yields and advantageous properties of the obtained material. The preparation of new, effective, and bio-safe catalytic systems for the synthesis of biomedical polymers is one of the main directions of the research in modern medical chemistry. The new diethylzinc/propyl gallate catalytic system was first used in the copolymerization of ε-caprolactone and rac-lactide. In this paper, the activity of the new zinc-based catalytic system in the copolymerization of cyclic esters depending on the reaction conditions was described. The microstructure analysis of the obtained copolyesters and their toxicity studies were performed. Resulted copolyesters were characterized by low toxicity, moderate dispersity (1.19–1.71), varying randomness degree (0.18–0.83), and average molar mass (5300–9800 Da).
25
Burelo, Manuel, Araceli Martínez, Josué David Hernández-Varela, Thomas Stringer, Monserrat Ramírez-Melgarejo, Alice Y. Yau, Gabriel Luna-Bárcenas e Cecilia D. Treviño-Quintanilla. "Recent Developments in Synthesis, Properties, Applications and Recycling of Bio-Based Elastomers". Molecules 29, n. 2 (12 gennaio 2024): 387. http://dx.doi.org/10.3390/molecules29020387.
Testo completoAbstract (sommario):
In 2021, global plastics production was 390.7 Mt; in 2022, it was 400.3 Mt, showing an increase of 2.4%, and this rising tendency will increase yearly. Of this data, less than 2% correspond to bio-based plastics. Currently, polymers, including elastomers, are non-recyclable and come from non-renewable sources. Additionally, most elastomers are thermosets, making them complex to recycle and reuse. It takes hundreds to thousands of years to decompose or biodegrade, contributing to plastic waste accumulation, nano and microplastic formation, and environmental pollution. Due to this, the synthesis of elastomers from natural and renewable resources has attracted the attention of researchers and industries. In this review paper, new methods and strategies are proposed for the preparation of bio-based elastomers. The main goals are the advances and improvements in the synthesis, properties, and applications of bio-based elastomers from natural and industrial rubbers, polyurethanes, polyesters, and polyethers, and an approach to their circular economy and sustainability. Olefin metathesis is proposed as a novel and sustainable method for the synthesis of bio-based elastomers, which allows for the depolymerization or degradation of rubbers with the use of essential oils, terpenes, fatty acids, and fatty alcohols from natural resources such as chain transfer agents (CTA) or donors of the terminal groups in the main chain, which allow for control of the molecular weights and functional groups, obtaining new compounds, oligomers, and bio-based elastomers with an added value for the application of new polymers and materials. This tendency contributes to the development of bio-based elastomers that can reduce carbon emissions, avoid cross-contamination from fossil fuels, and obtain a greener material with biodegradable and/or compostable behavior.
26
Kelnar, Ivan, Ludmila Kaprálková, Pavel Němeček, Jiří Dybal, Rasha M. Abdel-Rahman, Michaela Vyroubalová, Martina Nevoralová e A. M. Abdel-Mohsen. "The Effects of the Deacetylation of Chitin Nanowhiskers on the Performance of PCL/PLA Bio-Nanocomposites". Polymers 15, n. 14 (17 luglio 2023): 3071. http://dx.doi.org/10.3390/polym15143071.
Testo completoAbstract (sommario):
The multiple roles of organic nanofillers in biodegradable nanocomposites (NC) with a blend-based matrix is not yet fully understood. This work highlights combination of reinforcing and structure-directing effects of chitin nanowhiskers (CNW) with different degrees of deacetylation (DA), i.e., content of primary or secondary amines on their surface, in the nanocomposite with the PCL/PLA 1:1 matrix. Of importance is the fact that aminolysis with CNW leading to chain scission of both polyesters, especially of PLA, is practically independent of DA. DA also does not influence thermal stability. At the same time, the more marked chain scission/CNW grafting for PLA in comparison to PCL, causing changes in rheological parameters of components and related structural alterations, has crucial effects on mechanical properties in systems with a bicontinuous structure. Favourable combinations of multiple effects of CNW leads to enhanced mechanical performance at low 1% content only, whereas negative effects of structural changes, particularly of changed continuity, may eliminate the reinforcing effects of CNW at higher contents. The explanation of both synergistic and antagonistic effects of structures formed is based on the correspondence of experimental results with respective basic model calculations.
27
Kopitzky, Rodion. "Poly(Lactic Acid)–Poly(Butylene Succinate)–Sugar Beet Pulp Composites; Part I: Mechanics of Composites with Fine and Coarse Sugar Beet Pulp Particles". Polymers 13, n. 15 (30 luglio 2021): 2531. http://dx.doi.org/10.3390/polym13152531.
Testo completoAbstract (sommario):
Sugar beet pulp (SBP) is a residue available in large quantities from the sugar industry, and can serve as a cost-effective bio-based and biodegradable filler for fully bio-based compounds based on bio-based polyesters. The heterogeneous cell structure of sugar beet suggests that the processing of SBP can affect the properties of the composite. An “Ultra-Rotor” type air turbulence mill was used to produce SBP particles of different sizes. These particles were processed in a twin-screw extruder with poly(lactic acid) (PLA) and poly(butylene succinate) (PBS) and fillers to granules for possible marketable formulations. Different screw designs, compatibilizers and the use of glycerol as a thermoplasticization agent for SBP were also tested. The spherical, cubic, or ellipsoidal-like shaped particles of SBP are not suitable for usage as a fiber-like reinforcement. In addition, the fineness of ground SBP affects the mechanical properties because (i) a high proportion of polar surfaces leads to poor compatibility, and (ii) due to the inner structure of the particulate matter, the strength of the composite is limited to the cohesive strength of compressed sugar-cell compartments of the SBP. The compatibilization of the polymer–matrix–particle interface can be achieved by using compatibilizers of different types. Scanning electron microscopy (SEM) fracture patterns show that the compatibilization can lead to both well-bonded particles and cohesive fracture patterns in the matrix. Nevertheless, the mechanical properties are limited by the impact and elongation behavior. Therefore, the applications of SBP-based composites must be well considered.
28
Bonferoni, Maria Cristina, Carla Caramella, Laura Catenacci, Bice Conti, Rossella Dorati, Franca Ferrari, Ida Genta et al. "Biomaterials for Soft Tissue Repair and Regeneration: A Focus on Italian Research in the Field". Pharmaceutics 13, n. 9 (26 agosto 2021): 1341. http://dx.doi.org/10.3390/pharmaceutics13091341.
Testo completoAbstract (sommario):
Tissue repair and regeneration is an interdisciplinary field focusing on developing bioactive substitutes aimed at restoring pristine functions of damaged, diseased tissues. Biomaterials, intended as those materials compatible with living tissues after in vivo administration, play a pivotal role in this area and they have been successfully studied and developed for several years. Namely, the researches focus on improving bio-inert biomaterials that well integrate in living tissues with no or minimal tissue response, or bioactive materials that influence biological response, stimulating new tissue re-growth. This review aims to gather and introduce, in the context of Italian scientific community, cutting-edge advancements in biomaterial science applied to tissue repair and regeneration. After introducing tissue repair and regeneration, the review focuses on biodegradable and biocompatible biomaterials such as collagen, polysaccharides, silk proteins, polyesters and their derivatives, characterized by the most promising outputs in biomedical science. Attention is pointed out also to those biomaterials exerting peculiar activities, e.g., antibacterial. The regulatory frame applied to pre-clinical and early clinical studies is also outlined by distinguishing between Advanced Therapy Medicinal Products and Medical Devices.
29
Todea, Bîtcan, Aparaschivei, Păușescu, Badea, Péter, Gherman, Rusu, Nagy e Kéki. "Biodegradable Oligoesters of ε-Caprolactone and 5-Hydroxymethyl-2-Furancarboxylic Acid Synthesized by Immobilized Lipases". Polymers 11, n. 9 (26 agosto 2019): 1402. http://dx.doi.org/10.3390/polym11091402.
Testo completoAbstract (sommario):
Following the latest developments, bio-based polyesters, obtained from renewable raw materials, mainly carbohydrates, can be competitive for the fossil-based equivalents in various industries. In particular, the furan containing monomers are valuable alternatives for the synthesis of various new biomaterials, applicable in food additive, pharmaceutical and medical field. The utilization of lipases as biocatalysts for the synthesis of such polymeric compounds can overcome the disadvantages of high temperatures and metal catalysts, used by the chemical route. In this work, the enzymatic synthesis of new copolymers of ε-caprolactone and 5-hydroxymethyl-2-furancarboxylic acid has been investigated, using commercially available immobilized lipases from Candida antarctica B. The reactions were carried out in solvent-less systems, at temperatures up to 80 °C. The structural analysis by MALDI TOF-MS, NMR, and FT-IR spectroscopy confirmed the formation of cyclic and linear oligoesters, with maximal polymerization degree of 24 and narrow molecular weight distribution (dispersity about 1.1). The operational stability of the biocatalyst was explored during several reuses, while thermal analysis (TG and DSC) indicated a lower thermal stability and higher melting point of the new products, compared to the poly(ε-caprolactone) homopolymer. The presence of the heterocyclic structure in the polymeric chain has promoted both the lipase-catalyzed degradation and the microbial degradation. Although, poly(ε-caprolactone) is a valuable biocompatible polymer with important therapeutic applications, some drawbacks such as low hydrophilicity, low melting point, and relatively slow biodegradability impeded its extensive utilization. In this regard the newly synthesized furan-based oligoesters could represent a “green” improvement route.
30
Satchanska, Galina, Slavena Davidova e Petar D. Petrov. "Natural and Synthetic Polymers for Biomedical and Environmental Applications". Polymers 16, n. 8 (20 aprile 2024): 1159. http://dx.doi.org/10.3390/polym16081159.
Testo completoAbstract (sommario):
Natural and synthetic polymers are a versatile platform for developing biomaterials in the biomedical and environmental fields. Natural polymers are organic compounds that are found in nature. The most common natural polymers include polysaccharides, such as alginate, hyaluronic acid, and starch, proteins, e.g., collagen, silk, and fibrin, and bacterial polyesters. Natural polymers have already been applied in numerous sectors, such as carriers for drug delivery, tissue engineering, stem cell morphogenesis, wound healing, regenerative medicine, food packaging, etc. Various synthetic polymers, including poly(lactic acid), poly(acrylic acid), poly(vinyl alcohol), polyethylene glycol, etc., are biocompatible and biodegradable; therefore, they are studied and applied in controlled drug release systems, nano-carriers, tissue engineering, dispersion of bacterial biofilms, gene delivery systems, bio-ink in 3D-printing, textiles in medicine, agriculture, heavy metals removal, and food packaging. In the following review, recent advancements in polymer chemistry, which enable the imparting of specific biomedical functions of polymers, will be discussed in detail, including antiviral, anticancer, and antimicrobial activities. This work contains the authors’ experimental contributions to biomedical and environmental polymer applications. This review is a vast overview of natural and synthetic polymers used in biomedical and environmental fields, polymer synthesis, and isolation methods, critically assessessing their advantages, limitations, and prospects.
31
Giubilini, Alberto, Federica Bondioli, Massimo Messori, Gustav Nyström e Gilberto Siqueira. "Advantages of Additive Manufacturing for Biomedical Applications of Polyhydroxyalkanoates". Bioengineering 8, n. 2 (23 febbraio 2021): 29. http://dx.doi.org/10.3390/bioengineering8020029.
Testo completoAbstract (sommario):
In recent years, biopolymers have been attracting the attention of researchers and specialists from different fields, including biotechnology, material science, engineering, and medicine. The reason is the possibility of combining sustainability with scientific and technological progress. This is an extremely broad research topic, and a distinction has to be made among different classes and types of biopolymers. Polyhydroxyalkanoate (PHA) is a particular family of polyesters, synthetized by microorganisms under unbalanced growth conditions, making them both bio-based and biodegradable polymers with a thermoplastic behavior. Recently, PHAs were used more intensively in biomedical applications because of their tunable mechanical properties, cytocompatibility, adhesion for cells, and controllable biodegradability. Similarly, the 3D-printing technologies show increasing potential in this particular field of application, due to their advantages in tailor-made design, rapid prototyping, and manufacturing of complex structures. In this review, first, the synthesis and the production of PHAs are described, and different production techniques of medical implants are compared. Then, an overview is given on the most recent and relevant medical applications of PHA for drug delivery, vessel stenting, and tissue engineering. A special focus is reserved for the innovations brought by the introduction of additive manufacturing in this field, as compared to the traditional techniques. All of these advances are expected to have important scientific and commercial applications in the near future.
32
Djouonkep, Lesly Dasilva Wandji, Christian Tatchum Tamo, Belle Elda Simo, Nasiru Issah, Marc Nivic Tchouagtie, Naomie Beolle Songwe Selabi, Ingo Doench, Arnaud Kamdem Kamdem Tamo, Binqiang Xie e Anayancy Osorio-Madrazo. "Synthesis by Melt-Polymerization of a Novel Series of Bio-Based and Biodegradable Thiophene-Containing Copolyesters with Promising Gas Barrier and High Thermomechanical Properties". Molecules 28, n. 4 (15 febbraio 2023): 1825. http://dx.doi.org/10.3390/molecules28041825.
Testo completoAbstract (sommario):
Volatile global oil prices, owing to the scarcity of fossil resources, have impacted the cost of producing petrochemicals. Therefore, there is a need to seek novel, renewable chemicals from biomass feedstocks that have comparable properties to petrochemicals. In this study, synthesis, thermal and mechanical properties, and degradability studies of a novel series of sustainable thiophene-based copolyesters like poly(hexylene 2,5-thiophenedicarboxylate-co-bis(2-hydroxyethoxybenzene) (PTBxHy) were conducted via a controlled melt polymerization method. Fourier-transform infrared (FTIR) and nuclear magnetic resonance (1H NMR) spectroscopy techniques elucidated the degree of randomness and structural properties of copolyesters. Meanwhile, gel permeation chromatography (GPC) analysis showed a high average molecular weight in the range of 67.4–78.7 × 103 g/mol. The glass transition temperature (Tg) was between 69.4 and 105.5 °C, and the melting point between 173.7 and 194.2 °C. The synthesized polymers outperformed poly(ethylene 2,5-thiophenedicarboxylate) (PETF) and behaved similarly to poly(ethylene terephthalate) (PET). The copolyesters exhibited a high tensile strength of 46.4–70.5 MPa and a toughness of more than 600%, superior to their corresponding homopolyesters. The copolyesters, which ranged from 1,4-bis(2-hydroxyethyl)benzene thiophenedicarboxylate (TBB)-enriched to hexylene thiophenedicarboxylate (THH)-enriched, offered significant control over crystallinity, thermal and mechanical properties. Enzymatic hydrolysis of synthetized polymers using porcine pancreatic lipase (PP-L) over a short period resulted in significant weight losses of 9.6, 11.4, 30.2, and 35 wt%, as observed by scanning electron microscopy (SEM), with perforations visible on all surfaces of the films. Thus, thiophene-based polyesters with cyclic aromatic structures similar to terephthalic acid (TPA) show great promise as PET mimics. At the same time, PP-L appears to be a promising biocatalyst for the degradation of bioplastic waste and its recycling via re-synthesis processes.
33
Ivanova, Bojidarka. "Stochastic dynamics mass spectrometric and Fourier transform infrared spectroscopic structural analyses of composite biodegradable plastics". Pollution Study 5, n. 1 (22 luglio 2024): 2741. http://dx.doi.org/10.54517/ps.v5i1.2741.
Testo completoAbstract (sommario):
<p>The (partial) replacement of synthetic polymers with bioplastics is due to increased production of conventional packaging plastics causing for severe environmental pollution with plastics waste. The bioplastics, however, represent complex mixtures of known and unknown (bio)polymers, fillers, plasticizers, stabilizers, flame retardant, pigments, antioxidants, hydrophobic polymers such as poly(lactic acid), polyethylene, polyesters, glycol, or poly(butylene succinate), and little is known of their chemical safety for both the environment and the human health. Polymerization reactions of bioplastics can produce no intentionally added chemicals to the bulk material, which could be toxic, as well. When polymers are used to food packing, then the latter chemicals could also migrate from the polymer to food. This fact compromises the safety for consumers, as well. The scarce data on chemical safety of bioplastics makes a gap in knowledge of their toxicity to humans and environment. Thus, development of exact analytical protocols for determining chemicals of bioplastics in environmental and food samples as well as packing polymers can only provide warrant for reliable conclusive evidence of their safety for both the human health and the environment. The task is compulsory according to legislation Directives valid to environmental protection, food control, and assessment of the risk to human health. The quantitative and structural determination of analytes is primary research task of analysis of polymers. The methods of mass spectrometry are fruitfully used for these purposes. Methodological development of exact analytical mass spectrometric tools for reliable structural analysis of bioplastics only guarantees their safety, efficacy, and quality to both humans and environment. This study, first, highlights innovative stochastic dynamics equations processing exactly mass spectrometric measurands and, thus, producing exact analyte quantification and 3D molecular and electronic structural analyses. There are determined synthetic polymers such as poly(ethylenglycol), poly(propylene glycol), and polyisoprene as well as biopolymers in bags for foodstuffs made from renewable cellulose and starch, and containing, in total within the 20,416–17,495 chemicals per sample of the composite biopolymers. Advantages of complementary employment in mass spectrometric methods and Fourier transform infrared spectroscopy is highlighted. The study utilizes ultra-high resolution electrospray ionization mass spectrometric and Fourier transform infrared spectroscopic data on biodegradable plastics bags for foodstuffs; high accuracy quantum chemical static methods, molecular dynamics; and chemometrics. There is achieved method performance |<em>r</em>| = 0.99981 determining poly(propylene glycol) in bag for foodstuff containing 20,416 species and using stochastic dynamics mass spectrometric formulas. The results highlight their great capability and applicability to the analytical science as well as relevance to both the fundamental research and to the industry.</p>
34
Ivanova, Bojidarka. "Stochastic dynamics mass spectrometric and Fourier transform infrared spectroscopic structural analyses of composite biodegradable plastics". Pollution Study 5, n. 2 (22 settembre 2024): 2741. http://dx.doi.org/10.54517/ps.v5i2.2741.
Testo completoAbstract (sommario):
<p>The (partial) replacement of synthetic polymers with bioplastics is due to increased production of conventional packaging plastics causing for severe environmental pollution with plastics waste. The bioplastics, however, represent complex mixtures of known and unknown (bio)polymers, fillers, plasticizers, stabilizers, flame retardant, pigments, antioxidants, hydrophobic polymers such as poly(lactic acid), polyethylene, polyesters, glycol, or poly(butylene succinate), and little is known of their chemical safety for both the environment and the human health. Polymerization reactions of bioplastics can produce no intentionally added chemicals to the bulk material, which could be toxic, as well. When polymers are used to food packing, then the latter chemicals could also migrate from the polymer to food. This fact compromises the safety for consumers, as well. The scarce data on chemical safety of bioplastics makes a gap in knowledge of their toxicity to humans and environment. Thus, development of exact analytical protocols for determining chemicals of bioplastics in environmental and food samples as well as packing polymers can only provide warrant for reliable conclusive evidence of their safety for both the human health and the environment. The task is compulsory according to legislation Directives valid to environmental protection, food control, and assessment of the risk to human health. The quantitative and structural determination of analytes is primary research task of analysis of polymers. The methods of mass spectrometry are fruitfully used for these purposes. Methodological development of exact analytical mass spectrometric tools for reliable structural analysis of bioplastics only guarantees their safety, efficacy, and quality to both humans and environment. This study, first, highlights innovative stochastic dynamics equations processing exactly mass spectrometric measurands and, thus, producing exact analyte quantification and 3D molecular and electronic structural analyses. There are determined synthetic polymers such as poly(ethylenglycol), poly(propylene glycol), and polyisoprene as well as biopolymers in bags for foodstuffs made from renewable cellulose and starch, and containing, in total within the 20,416–17,495 chemicals per sample of the composite biopolymers. Advantages of complementary employment in mass spectrometric methods and Fourier transform infrared spectroscopy is highlighted. The study utilizes ultra-high resolution electrospray ionization mass spectrometric and Fourier transform infrared spectroscopic data on biodegradable plastics bags for foodstuffs; high accuracy quantum chemical static methods, molecular dynamics; and chemometrics. There is achieved method performance |<em>r</em>| = 0.99981 determining poly(propylene glycol) in bag for foodstuff containing 20,416 species and using stochastic dynamics mass spectrometric formulas. The results highlight their great capability and applicability to the analytical science as well as relevance to both the fundamental research and to the industry.</p>
35
Ehsani, Masoume, Denis Kalugin, Huu Doan, Ali Lohi e Amira Abdelrasoul. "Bio-Sourced and Biodegradable Membranes". Applied Sciences 12, n. 24 (14 dicembre 2022): 12837. http://dx.doi.org/10.3390/app122412837.
Testo completoAbstract (sommario):
Biodegradable membranes with innovative antifouling properties are emerging as possible substitutes for conventional membranes. These types of membranes have the potential to be applied in a wide range of applications, from water treatment to food packaging and energy production. Nevertheless, there are several existing challenges and limitations associated with the use of biodegradable membranes in large scale applications, and further studies are required to determine the degradation mechanisms and their scalability. Biodegradable membranes can be produced from either renewable natural resources or synthesized from low-molecular monomers that increase the number of possible structures and, as a result, greatly expand the membrane application possibilities. This study focused on bio-sourced and synthesized biodegradable polymers as green membrane materials. Moreover, the article highlighted the excellent antifouling properties of biodegradable membranes that assist in improving membrane lifetime during filtration processes, preventing chemical/biological disposal due to frequent cleaning processes and ultimately reducing the maintenance cost. The industrial and biomedical applications of biodegradable membranes were also summarized, along with their limitations. Finally, an overview of challenges and future trends regarding the use of biodegradable membranes in various industries was thoroughly analyzed.
36
Aliotta, Laura, Alessandro Vannozzi, Luca Panariello, Vito Gigante, Maria-Beatrice Coltelli e Andrea Lazzeri. "Sustainable Micro and Nano Additives for Controlling the Migration of a Biobased Plasticizer from PLA-Based Flexible Films". Polymers 12, n. 6 (17 giugno 2020): 1366. http://dx.doi.org/10.3390/polym12061366.
Testo completoAbstract (sommario):
Plasticized poly(lactic acid) (PLA)/poly(butylene succinate) (PBS) blend-based films containing chitin nanofibrils (CN) and calcium carbonate were prepared by extrusion and compression molding. On the basis of previous studies, processability was controlled by the use of a few percent of a commercial acrylic copolymer acting as melt strength enhancer and calcium carbonate. Furthermore, acetyl n-tributyl citrate (ATBC), a renewable and biodegradable plasticizer (notoriously adopted in PLA based products) was added to facilitate not only the processability but also to increase the mechanical flexibility and toughness. However, during the storage of these films, a partial loss of plasticizer was observed. The consequence of this is not only correlated to the change of the mechanical properties making the films more rigid but also to the crystallization and development of surficial oiliness. The effect of the addition of calcium carbonate (nanometric and micrometric) and natural nanofibers (chitin nanofibrils) to reduce/control the plasticizer migration was investigated. The prediction of plasticizer migration from the films’ core to the external surface was carried out and the diffusion coefficients, obtained by regression of the experimental migration data plotted as the square root of time, were evaluated for different blends compositions. The results of the diffusion coefficients, obtained thanks to migration tests, showed that the CN can slow the plasticizer migration. However, the best result was achieved with micrometric calcium carbonate while nanometric calcium carbonate results were less effective due to favoring of some bio polyesters’ chain scission. The use of both micrometric calcium carbonate and CN was counterproductive due to the agglomeration phenomena that were observed.
37
LOLADZE, Tamar, e Nino KEBADZE. "Porous films (Scaffolds) for cell growing". Journal of Technical Science and Technologies 5, n. 1 (21 ottobre 2016): 27–28. http://dx.doi.org/10.31578/jtst.v5i1.97.
Testo completoAbstract (sommario):
We have obtained the biodegradable, bio-compatible scaffolds (base-film for cell growing) possessing well developed porous surface made of polyester amide 8-Phe-6 (poly-mer composed of sebacic, L phenylalanine and 1,6 – hexanediol). Porous films were ob-tained by ultrasonic or mechanical dispersion of two-phase system (water/biodegradable polyester amide solution in chloroform), followed by freezing of the obtained emulsion and subsequent freeze-drying.
38
Dutta, Geeti Kaberi, e Niranjan Karak. "Waste brewed tea leaf derived cellulose nanofiber reinforced fully bio-based waterborne polyester nanocomposite as an environmentally benign material". RSC Advances 9, n. 36 (2019): 20829–40. http://dx.doi.org/10.1039/c9ra02973g.
Testo completo
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Lizundia, Erlantz, Vishalkumar A. Makwana, Aitor Larrañaga, José Luis Vilas e Michael P. Shaver. "Thermal, structural and degradation properties of an aromatic–aliphatic polyester built through ring-opening polymerisation". Polymer Chemistry 8, n. 22 (2017): 3530–38. http://dx.doi.org/10.1039/c7py00695k.
Testo completoAbstract (sommario):
The novel biodegradable aromatic–aliphatic polyester, poly(2-(2-hydroxyethoxy)benzoate), was explored through thermal analysis, X-ray diffraction, dynamic mechanical analysis and comparative bio and catalysed degradation.
40
Zhao, Xipo, Huan Hu, Xin Wang, Xiaolei Yu, Weiyi Zhou e Shaoxian Peng. "Super tough poly(lactic acid) blends: a comprehensive review". RSC Advances 10, n. 22 (2020): 13316–68. http://dx.doi.org/10.1039/d0ra01801e.
Testo completoAbstract (sommario):
PLA is a renewable, bio-based, and biodegradable aliphatic thermoplastic polyester that is considered a promising alternative to petrochemical-derived polymers in a wide range of commodity and engineering applications.
41
Chanda, Sananda, e S. Ramakrishnan. "Poly(alkylene itaconate)s – an interesting class of polyesters with periodically located exo-chain double bonds susceptible to Michael addition". Polymer Chemistry 6, n. 11 (2015): 2108–14. http://dx.doi.org/10.1039/c4py01613k.
Testo completoAbstract (sommario):
Dibutyl itaconate, a bio-sourced monomer, is melt-condensed with various aliphatic diols to generate unsaturated polyesters carrying exo-chain double bonds; these exo-chain double bonds readily undergo Micheal addition with a variety of organic thiols and amines, including some derviatized amino acids, like cysteine and proline.
42
Dong, Weifu, Jingjiao Ren, Ling Lin, Dongjian Shi, Zhongbin Ni e Mingqing Chen. "Novel photocrosslinkable and biodegradable polyester from bio-renewable resource". Polymer Degradation and Stability 97, n. 4 (aprile 2012): 578–83. http://dx.doi.org/10.1016/j.polymdegradstab.2012.01.008.
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Gouda, Abdelaziz, Manuel Reali e Clara Santato. "Bio-Sourced, Potentially Biodegradable Materials for Fast Response Moisture Sensors". ECS Meeting Abstracts MA2020-01, n. 35 (1 maggio 2020): 2425. http://dx.doi.org/10.1149/ma2020-01352425mtgabs.
Testo completo
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Frank, Carina, Anita Emmerstorfer-Augustin, Thomas Rath, Gregor Trimmel, Manfred Nachtnebel e Franz Stelzer. "Bio-Polyester/Rubber Compounds: Fabrication, Characterization, and Biodegradation". Polymers 15, n. 12 (7 giugno 2023): 2593. http://dx.doi.org/10.3390/polym15122593.
Testo completoAbstract (sommario):
Biobased and biodegradable polymers (BBDs) such as poly(3-hydroxy-butyrate), PHB, and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) are considered attractive alternatives to fossil-based plastic materials since they are more environmentally friendly. One major problem with these compounds is their high crystallinity and brittleness. In order to generate softer materials without using fossil-based plasticizers, the suitability of natural rubber (NR) as an impact modifier was investigated in PHBV blends. Mixtures with varying proportions of NR and PHBV were generated, and samples were prepared by mechanical mixing (roll mixer and/or internal mixer) and cured by radical C–C crosslinking. The obtained specimens were investigated with respect to their chemical and physical characteristics, applying a variety of different methods such as size exclusion chromatography, Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermal analysis, XRD, and mechanical testing. Our results clearly indicate that NR–PHBV blends exhibit excellent material characteristics including high elasticity and durability. Additionally, biodegradability was tested by applying heterologously produced and purified depolymerases. pH shift assays and morphology analyses of the surface of depolymerase-treated NR–PHBV through electron scanning microscopy confirmed the enzymatic degradation of PHBV. Altogether, we prove that NR is highly suitable to substitute fossil-based plasticizers; NR–PHBV blends are biodegradable and, hence, should be considered as interesting materials for a great number of applications.
45
Todea, Anamaria, Caterina Deganutti, Mariachiara Spennato, Fioretta Asaro, Guglielmo Zingone, Tiziana Milizia e Lucia Gardossi. "Azelaic Acid: A Bio-Based Building Block for Biodegradable Polymers". Polymers 13, n. 23 (24 novembre 2021): 4091. http://dx.doi.org/10.3390/polym13234091.
Testo completoAbstract (sommario):
Azelaic acid is a dicarboxylic acid containing nine C atoms, industrially obtained from oleic acid. Besides its important properties and pharmacological applications, as an individual compound, azelaic acid has proved to be a valuable bio-based monomer for the synthesis of biodegradable and sustainable polymers, plasticizers and lubricants. This review discusses the studies and the state of the art in the field of the production of azelaic acid from oleic acid, the chemical and enzymatic synthesis of bio-based oligo and polyester and their properties, including biodegradability and biocompostability.
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Devi, Shapali, Sadguru Prakash, Ravindra Pratap Singh e Rahul Singh. "Polylactic Acid: A Bio-Based Polymer as an Emerging Substitute for Plastics". Scientific Temper 13, n. 02 (12 dicembre 2022): 55–64. http://dx.doi.org/10.58414/scientifictemper.2022.13.2.10.
Testo completoAbstract (sommario):
Bio-based polymers attract renewable focus due to natural stocks and the success of limitedpetroleum resources. Bio-based polymers not only replace polymers with a number ofdetails but also provide new compounds for collections for new details. A list of bio-basedpolymers presented in this review, focusing on global packaging methods, and marketableperformance. Unique processes have been performed to increase the activity and productionof similar polymers such as bumps, cellulose, and lactic acid. The quest to produce essentialproducts that can decompose in ever-changing waters such as detergents and cosmetics hascontinued to add value. Biodegradable polymers are mainly classified as agro polymers anddecaying polyester Singh et.al., 2018). Bio-polyester products are obtained mainly throughrenewable energy. Therefore, consumers are more aggressive with low or non-affiliate ratingsof biodegradability paper, leading to head-scratching on the basis of cost-effectiveness andproduct-friendly products. Additionally, there is no equivalent structure for the removal ofbiodegradable accoutrements in the end.
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Pandey, Vipul, Dr Rajeev Arya e Shravan Vishwakarma. "Polymer Characteristics Study to be Utilized as Waste to Energy Conversion System". SMART MOVES JOURNAL IJOSCIENCE 6, n. 11 (18 novembre 2020): 44–47. http://dx.doi.org/10.24113/ijoscience.v6i11.331.
Testo completoAbstract (sommario):
The interaction between synthetic polymers and the natural environment in terms of the effects of oxygen, radiant energy, and living organisms has been extensively studied over the past two decades. However, recent trends in environmental protection have aroused great public interest. This paper introduced polymer properties such as biodegradability and the Westas energy and organic waste for fuels and chemicals. Description of bio plastics and biodegradable plastics based on polyester.
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Wang, Zhaoshan, Jieqiong Yan, Tongyao Wang, Yingying Zai, Liyan Qiu e Qingguo Wang. "Fabrication and Properties of a Bio-Based Biodegradable Thermoplastic Polyurethane Elastomer". Polymers 11, n. 7 (2 luglio 2019): 1121. http://dx.doi.org/10.3390/polym11071121.
Testo completoAbstract (sommario):
Using the melt polycondensation of five bio-based aliphatic monomers (succinic acid, sebacic acid, fumaric acid, 1,3-propanediol, and 1,4-butanediol), we first synthesized the more flexible and biodegradable polyester diols (BPD) with an average molecular weight of 3825. Then, the BPD was polymerized with excessive 4,4′-diphenylmethane diisocyanate (MDI). Finally, the molecular chain extender of 1,4-butanediol (BDO) was used to fabricate the biodegradable thermoplastic polyurethane elastomer (BTPU), comprising the soft segment of BPD and the hard segment polymerized by MDI and BDO. Atomic force microscope (AFM) images showed the two-phase structure of the BTPU. The tensile strength of the BTPU containing 60% BPD was about 30 MPa and elongation at break of the BTPU was over 800%. Notably, the BTPU had superior biodegradability in lipase solution and the biodegradation weight loss ratio of the BTPU containing 80% BPD reached 36.7% within 14 days in the lipase solution.
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Namphonsane, Atitiya, Taweechai Amornsakchai, Chin Hua Chia, Kheng Lim Goh, Sombat Thanawan, Rungtiwa Wongsagonsup e Siwaporn Meejoo Smith. "Development of Biodegradable Rigid Foams from Pineapple Field Waste". Polymers 15, n. 13 (29 giugno 2023): 2895. http://dx.doi.org/10.3390/polym15132895.
Testo completoAbstract (sommario):
Pineapple materials sourced from agricultural waste have been employed to process novel bio-degradable rigid composite foams. The matrix for the foam consisted of starch extracted from pineapple stem, known for its high amylose content, while the filler comprised non-fibrous cellulosic materials sourced from pineapple leaf. In contrast to traditional methods that involve preparing a batter, this study adopted a unique approach where the starch gel containing glycerol were first formed using a household microwave oven, followed by blending the filler into the gel using a two-roll mill. The resulting mixture was then foamed at 160 °C using a compression molding machine. The foams displayed densities ranging from 0.43–0.51 g/cm3 and exhibited a highly amorphous structure. Notably, the foams demonstrated an equilibrium moisture content of approximately 8–10% and the ability to absorb 150–200% of their own weight without disintegration. Flexural strengths ranged from 1.5–4.5 MPa, varying with the filler and glycerol contents. Biodegradability tests using a soil burial method revealed complete disintegration of the foam into particles measuring 1 mm or smaller within 15 days. Moreover, to showcase practical applications, an environmentally friendly single-use foam tray was fabricated. This novel method, involving gel formation followed by filler blending, sets it apart from previous works. The findings highlight the potential of pineapple waste materials for producing sustainable bio-degradable foams with desirable properties and contribute to the field of sustainable materials.
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UĞUR NİGİZ, Filiz, e Buket ONAT. "Investigation of the potential use of halloysite nanotube doped chitosan films for food packaging". Journal of Amasya University the Institute of Sciences and Technology 4, n. 2 (31 dicembre 2023): 108–15. http://dx.doi.org/10.54559/jauist.1404602.
Testo completoAbstract (sommario):
Polymer-based food packaging is widely used and causes serious environmental problems due to the chemical ingredients. Therefore, these packages should be replaced by biodegradable alternatives in order to prevent environmental pollution. Many biodegradable polymers are used in food packaging. Among them, chitosan is gaining attention since it is bio-sourced and biodegradable. In this study, the usability of chitosan films as physical and chemical tests investigated food packaging. In order to improve the packaging properties of the films, halloysite nanotube was used as filler with a concentration range of 1-4 wt.%. It was observed that the halloysite significantly increased the opacity, mechanical strength, water resistance, and antioxidant properties of the films.