Biobased and Biodegradable Polymer Blends and Composites

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

Deadline for manuscript submissions: closed (25 April 2023) | Viewed by 35820

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Guest Editor
Department of Civil and Industrial Engineering, University of Pisa, 56122 Pisa, Italy
Interests: materials science; natural fibers; natural fillers; composites; polymers; biopolymers; bioplastics; biocomposites; polymer processing; mechanical properties; thermal properties; analytical modelling
Special Issues, Collections and Topics in MDPI journals

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Guest Editor
Department of Civil and Industrial Engineering, Università di Pisa, Largo Lucio Lazzarino 1, 56122 Pisa, Italy
Interests: processing; rheology; mechanical properties; fracture mechanics and thermal behavior of polymers and biocomposites
Special Issues, Collections and Topics in MDPI journals

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Guest Editor
Department of Civil and Industrial Engineering, University of Pisa, 56122 Pisa, Italy
Interests: materials Science; materials engineering; composites; nanomaterials; polymers; biopolymers; bioplastics; nanobiocomposites; polymer processing; mechanical properties; viscoelasticity; modelling
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

There is a growing interest towards biobased polymer and biocomposite development in order to obtain more sustainable and eco-efficient products. In particular, the increasing preoccupation caused by the disposal of conventional plastics has pressed researchers towards the development of new biobased and/or biodegradable blends and composites that are able to replace fossil-based products in different sectors. However, the modulation of the starting biopolymer thermomechanical properties is fundamental to reaching the thermal, mechanical, and, in some cases, barrier properties required by the different fields of application in which these bioplastics can enter into the market. For this purpose, an economical and convenient strategy for developing new polymeric formulations is the blending technique in which it is possible to combine the physical and mechanical advantages of different polymers. Nevertheless, the addition of natural fibers can be an efficient solution, not only to reduce the cost of the biopolymeric matrix but also to promote the biodegradability. According to the fiber critical length, the final biocomposites can exhibit enhanced physical and mechanical properties if compared to the individual components.

Dr. Laura Aliotta
Prof. Dr. Andrea Lazzeri
Dr. Vito Gigante
Guest Editors

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Keywords

  • biopolymers
  • biocomposites
  • mechanical properties
  • biodegradability
  • natural fibers
  • polymer blending

Published Papers (12 papers)

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Research

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16 pages, 7305 KiB  
Article
Interactions, Structure and Properties of PLA/lignin/PBAT Hybrid Blends
by Emese Pregi, Imre Romsics, Róbert Várdai and Béla Pukánszky
Polymers 2023, 15(15), 3237; https://0-doi-org.brum.beds.ac.uk/10.3390/polym15153237 - 29 Jul 2023
Cited by 1 | Viewed by 1807
Abstract
Poly(butylene adipate-co-terephthalate) (PBAT) was added to poly(lactic acid) (PLA)/lignin blends to decrease the considerable stiffness and brittleness of the blends. Two- and three-component blends were prepared in a wide composition range through homogenization in an internal mixer followed by compression molding. Interactions among [...] Read more.
Poly(butylene adipate-co-terephthalate) (PBAT) was added to poly(lactic acid) (PLA)/lignin blends to decrease the considerable stiffness and brittleness of the blends. Two- and three-component blends were prepared in a wide composition range through homogenization in an internal mixer followed by compression molding. Interactions among the components were estimated by comparing the solubility parameters of the materials used and through thermal analysis. Mechanical properties were characterized by tensile testing. The structure of the blends was studied using scanning electron (SEM) and digital optical (DOM) microscopy. The results showed that the interactions between PBAT and lignin are somewhat stronger than those between PLA and the other two components. The maleic anhydride grafted PLA added as a coupling agent proved completely ineffective; it does not modify the interactions. The structural analysis confirmed the immiscibility of the components; the structure of the blends was heterogeneous at each composition. A dispersed structure formed when the concentration of one of the components was small, while, depending on lignin content, an interpenetrating network-like structure developed and phase inversion took place in the range of 30–60 vol% PBAT content. Lignin was located mainly in the PBAT phase. Properties were determined by the relative amount of PBAT and PLA; the addition of lignin deteriorated properties, mainly the deformability of the blends. Other means, such as reactive processing, must be used to improve compatibility and blend properties. The results contribute considerably to a better understanding of structure–property correlations in lignin-based hybrid blends. Full article
(This article belongs to the Special Issue Biobased and Biodegradable Polymer Blends and Composites)
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16 pages, 7063 KiB  
Article
Super-Tough and Biodegradable Poly(lactide-co-glycolide) (PLGA) Transparent Thin Films Toughened by Star-Shaped PCL-b-PDLA Plasticizers
by Jieun Jeong, Sangsoo Yoon, Xin Yang and Young Jun Kim
Polymers 2023, 15(12), 2617; https://0-doi-org.brum.beds.ac.uk/10.3390/polym15122617 - 08 Jun 2023
Cited by 2 | Viewed by 1436
Abstract
To obtain fully degradable and super-tough poly(lactide-co-glycolide) (PLGA) blends, biodegradable star-shaped PCL-b-PDLA plasticizers were synthesized using natural originated xylitol as initiator. These plasticizers were blended with PLGA to prepare transparent thin films. Effects of added star-shaped PCL-b-PDLA plasticizers on [...] Read more.
To obtain fully degradable and super-tough poly(lactide-co-glycolide) (PLGA) blends, biodegradable star-shaped PCL-b-PDLA plasticizers were synthesized using natural originated xylitol as initiator. These plasticizers were blended with PLGA to prepare transparent thin films. Effects of added star-shaped PCL-b-PDLA plasticizers on mechanical, morphological, and thermodynamic properties of PLGA/star-shaped PCL-b-PDLA blends were investigated. The stereocomplexation strong cross-linked network between PLLA segment and PDLA segment effectively enhanced interfacial adhesion between star-shaped PCL-b-PDLA plasticizers and PLGA matrix. With only 0.5 wt% addition of star-shaped PCL-b-PDLA (Mn = 5000 g/mol), elongation at break of the PLGA blend reached approximately 248%, without any considerable sacrifice over excellent mechanical strength and modulus of PLGA. Full article
(This article belongs to the Special Issue Biobased and Biodegradable Polymer Blends and Composites)
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16 pages, 2817 KiB  
Article
Accelerated Degradation of Poly-ε-caprolactone Composite Scaffolds for Large Bone Defects
by Evangelos Daskalakis, Mohamed H. Hassan, Abdalla M. Omar, Anil A. Acar, Ali Fallah, Glen Cooper, Andrew Weightman, Gordon Blunn, Bahattin Koc and Paulo Bartolo
Polymers 2023, 15(3), 670; https://0-doi-org.brum.beds.ac.uk/10.3390/polym15030670 - 28 Jan 2023
Cited by 8 | Viewed by 1705
Abstract
This research investigates the accelerated hydrolytic degradation process of both anatomically designed bone scaffolds with a pore size gradient and a rectangular shape (biomimetically designed scaffolds or bone bricks). The effect of material composition is investigated considering poly-ε-caprolactone (PCL) as the main scaffold [...] Read more.
This research investigates the accelerated hydrolytic degradation process of both anatomically designed bone scaffolds with a pore size gradient and a rectangular shape (biomimetically designed scaffolds or bone bricks). The effect of material composition is investigated considering poly-ε-caprolactone (PCL) as the main scaffold material, reinforced with ceramics such as hydroxyapatite (HA), β-tricalcium phosphate (TCP) and bioglass at a concentration of 20 wt%. In the case of rectangular scaffolds, the effect of pore size (200 μm, 300 μm and 500 μm) is also investigated. The degradation process (accelerated degradation) was investigated during a period of 5 days in a sodium hydroxide (NaOH) medium. Degraded bone bricks and rectangular scaffolds were measured each day to evaluate the weight loss of the samples, which were also morphologically, thermally, chemically and mechanically assessed. The results show that the PCL/bioglass bone brick scaffolds exhibited faster degradation kinetics in comparison with the PCL, PCL/HA and PCL/TCP bone bricks. Furthermore, the degradation kinetics of rectangular scaffolds increased by increasing the pore size from 500 μm to 200 μm. The results also indicate that, for the same material composition, bone bricks degrade slower compared with rectangular scaffolds. The scanning electron microscopy (SEM) images show that the degradation process was faster on the external regions of the bone brick scaffolds (600 μm pore size) compared with the internal regions (200 μm pore size). The thermal gravimetric analysis (TGA) results show that the ceramic concentration remained constant throughout the degradation process, while differential scanning calorimetry (DSC) results show that all scaffolds exhibited a reduction in crystallinity (Xc), enthalpy (Δm) and melting temperature (Tm) throughout the degradation process, while the glass transition temperature (Tg) slightly increased. Finally, the compression results show that the mechanical properties decreased during the degradation process, with PCL/bioglass bone bricks and rectangular scaffolds presenting higher mechanical properties with the same design in comparison with the other materials. Full article
(This article belongs to the Special Issue Biobased and Biodegradable Polymer Blends and Composites)
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15 pages, 7469 KiB  
Article
Accelerated Laboratory Weathering of Polypropylene/Poly (Lactic Acid) Blends
by Qihua Zhou, Xuan Liu, Yanzhen Lu, Xiaoyao Dao and Liuqing Qiu
Polymers 2023, 15(1), 17; https://0-doi-org.brum.beds.ac.uk/10.3390/polym15010017 - 21 Dec 2022
Cited by 3 | Viewed by 1424
Abstract
To solve the pollution problems that result from polypropylene (PP), suitable biopolymers such as poly (lactic acid) (PLA) were selected to blend with PP. Since PP/PLA blends are often exposed to the natural environment, it is necessary to study the photodegradation behavior of [...] Read more.
To solve the pollution problems that result from polypropylene (PP), suitable biopolymers such as poly (lactic acid) (PLA) were selected to blend with PP. Since PP/PLA blends are often exposed to the natural environment, it is necessary to study the photodegradation behavior of PP/PLA blends. In this paper, PP/PLA blends with different compositions were prepared by extrusion and subjected to the accelerated laboratory weathering equipment. The effects of compatibilizers on the degradation behavior of PP/PLA blends were also studied. The weatherability of PP/PLA blends was studied through weight loss, optical microscope, Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The results revealed that PP is easy to degrade than PLA during accelerated laboratory weathering. PP/PLA blends are susceptible to the accelerated laboratory weathering process, and PP-rich and PLA-rich blends reduce the weathering resistance. Moreover, the results indicate that the initial degradation temperature, melting temperature, and crystallization temperature decrease after weathering related to the decreased thermal stability of PP/PLA blends. For instance, the initial degradation temperature of PP/PLA8.2 reduces from 332.2 °C to 320.2 °C. Moreover, the compatibilized sample is generally more resistant to weathering conditions than the uncompatibilized one due to the higher compatibility of PP and PLA. Full article
(This article belongs to the Special Issue Biobased and Biodegradable Polymer Blends and Composites)
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16 pages, 4922 KiB  
Article
Structural Characterization and Glycosaminoglycan Impurities Analysis of Chondroitin Sulfate from Chinese Sturgeon
by Mei Zhao, Yong Qin, Ying Fan, Xu Wang, Haixin Yi, Xiaoyu Cui, Fuchuan Li and Wenshuang Wang
Polymers 2022, 14(23), 5311; https://0-doi-org.brum.beds.ac.uk/10.3390/polym14235311 - 05 Dec 2022
Viewed by 1428
Abstract
Chinese sturgeon was an endangered cartilaginous fish. The success of artificial breeding has promoted it to a food fish and it is now beginning to provide a new source of cartilage for the extraction of chondroitin sulfate (CS). However, the structural characteristics of [...] Read more.
Chinese sturgeon was an endangered cartilaginous fish. The success of artificial breeding has promoted it to a food fish and it is now beginning to provide a new source of cartilage for the extraction of chondroitin sulfate (CS). However, the structural characteristics of sturgeon CS from different tissues remain to be determined in more detail. In this study, CSs from the head, backbone, and fin cartilage of Chinese sturgeon were individually purified and characterized for the first time. The molecular weights, disaccharide compositions, and oligosaccharide sulfation patterns of these CSs are significantly different. Fin CS (SFCS), rich in GlcUAα1-3GalNAc(4S), has the biggest molecular weight (26.5 kDa). In contrast, head CS (SHCS) has a molecular weight of 21.0 kDa and is rich in GlcUAα1-3GalNAc(6S). Most features of backbone CS (SBCS) are between the former two. Other glycosaminoglycan impurities in these three sturgeon-derived CSs were lower than those in other common commercial CSs. All three CSs have no effect on the activity of thrombin or Factor Xa in the presence of antithrombin III. Hence, Chinese sturgeon cartilage is a potential source for the preparation of CSs with different features for food and pharmaceutical applications. Full article
(This article belongs to the Special Issue Biobased and Biodegradable Polymer Blends and Composites)
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19 pages, 3748 KiB  
Article
Improvement of Interfacial Adhesion and Thermomechanical Properties of PLA Based Composites with Wheat/Rice Bran
by Vito Gigante, Laura Aliotta, Ilaria Canesi, Marco Sandroni, Andrea Lazzeri, Maria-Beatrice Coltelli and Patrizia Cinelli
Polymers 2022, 14(16), 3389; https://0-doi-org.brum.beds.ac.uk/10.3390/polym14163389 - 19 Aug 2022
Cited by 8 | Viewed by 2196
Abstract
The present work aims to enhance the use of agricultural byproducts for the production of bio-composites by melt extrusion. It is well known that in the production of such bio-composites, the weak point is the filler-matrix interface, for this reason the adhesion between [...] Read more.
The present work aims to enhance the use of agricultural byproducts for the production of bio-composites by melt extrusion. It is well known that in the production of such bio-composites, the weak point is the filler-matrix interface, for this reason the adhesion between a polylactic acid (PLA)/poly(butylene succinate)(PBSA) blend and rice and wheat bran platelets was enhanced by a treatment method applied on the fillers using a suitable beeswax. Moreover, the coupling action of beeswax and inorganic fillers (such as talc and calcium carbonate) were investigated to improve the thermo-mechanical properties of the final composites. Through rheological (MFI), morphological (SEM), thermal (TGA, DSC), mechanical (Tensile, Impact), thermomechanical (HDT) characterizations and the application of analytical models, the optimum among the tested formulations was then selected. Full article
(This article belongs to the Special Issue Biobased and Biodegradable Polymer Blends and Composites)
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15 pages, 6634 KiB  
Article
Biodegradable Films Prepared from Pulp Lignocellulose Adhesives of Urea Formaldehyde Resin Modified by Biosulfonate
by Yongjie Ma, Yanxin Luo, Qiannan Zhang, Yanming Gao, Jianshe Li, Sadiq Shah, Xiaozhuo Wang and Xueyan Zhang
Polymers 2022, 14(14), 2863; https://0-doi-org.brum.beds.ac.uk/10.3390/polym14142863 - 14 Jul 2022
Cited by 2 | Viewed by 2187
Abstract
Traditional low-density polyethylene (LDPE) film causes environmental pollution; there is a pressing need to make new bio-based polymers for alternative products, to meet agricultural production needs and for sustainable ecological development. In this study, urea-formaldehyde resin (UF) was modified with polyvinyl alcohol (PVA) [...] Read more.
Traditional low-density polyethylene (LDPE) film causes environmental pollution; there is a pressing need to make new bio-based polymers for alternative products, to meet agricultural production needs and for sustainable ecological development. In this study, urea-formaldehyde resin (UF) was modified with polyvinyl alcohol (PVA) and 1–2.5% bio-based sulfonate (BBS). The influence of BBS inducing on the functional groups, microstructure, and thermal behavior was evaluated by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). A biodegradable film was prepared with modified UF resin as adhesive and pulp lignocellulose as raw material. The biodegradable mulch film samples were tested for biodegradability, water retention, and cooling soil temperature characters using LDPE and no mulching (NM) as a control. The results showed that with the increase of BBS content, the viscosity and reactivity of modified PUF resin increased, and the free formaldehyde content decreased. A 2%BBS modified PUF resin (2.0BBS/PUF) accelerated the curing process of the PUF resin, formed a flexible macromolecular network structure, and enhanced the toughness of the resin. The biodegradable mulch prepared with PUF, BBS, and 2.0BBS/PUF as adhesives had good water retention. BBS modification increased the degradation rate of mulch by 17.53% compared to the PUF. Three biodegradable films compared with LDPE and NM significantly reduced the soil temperature under summer cucumber cultivation, and the 2.0BBS/PUF coating had the lowest diurnal temperature difference, which provided a suitable soil environment for crop growth. Full article
(This article belongs to the Special Issue Biobased and Biodegradable Polymer Blends and Composites)
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20 pages, 774 KiB  
Article
Odor-Reduced HDPE-Lignin Blends by Use of Processing Additives
by Bianca Lok, Gunnar Mueller, Andrea Buettner, Melanie Bartel and Jens Erdmann
Polymers 2022, 14(13), 2660; https://0-doi-org.brum.beds.ac.uk/10.3390/polym14132660 - 29 Jun 2022
Cited by 1 | Viewed by 2158
Abstract
The comprehensive use of natural polymers, such as lignin, can accelerate the replacement of mineral oil-based commodities. Promoting the material recovery of the still underutilized technical lignin, polyolefin-lignin blends are a highly promising approach towards sustainable polymeric materials. However, a limiting factor for [...] Read more.
The comprehensive use of natural polymers, such as lignin, can accelerate the replacement of mineral oil-based commodities. Promoting the material recovery of the still underutilized technical lignin, polyolefin-lignin blends are a highly promising approach towards sustainable polymeric materials. However, a limiting factor for high-quality applications is the unpleasant odor of technical lignin and resulting blends. The latter, especially, are a target for potential odor reduction, since heat- and shear-force intense processing can intensify the smell. In the present study, the odor optimization of kraft and soda HDPE-lignin blends was implemented by the in-process application of two different processing additives–5% of activated carbon and 0.7% of a stripping agent. Both additives were added directly within the compounding process executed with a twin screw extruder. The odor properties of the produced blends were assessed systematically by a trained human panel performing sensory evaluations of the odor characteristics. Subsequently, causative odor-active molecules were elucidated by means of GC-O and 2D-GC-MS/O while OEDA gave insights into relative odor potencies of single odorants. Out of 70 different odorants detected in the entirety of the sample material, more than 30 sulfur-containing odorants were present in the kraft HDPE-lignin blend, most of them neo-formed due to high melt temperatures during extrusion, leading to strong burnt and sulfurous smells. The addition of activated carbon significantly decreased especially these sulfurous compounds, resulting in 48% of overall odor reduction of the kraft blend (mean intensity ratings of 5.2) in comparison to the untreated blend (10.0). The applied stripping agent, an aqueous solution of polymeric, surface-active substances adsorbed onto a PP carrier, was less powerful in reducing neo-formed sulfur odorants, but led to a decrease in odor of 26% in the case of the soda HDPE-lignin blend (7.4). The identification of single odorants on a molecular level further enabled the elucidation of odor reduction trends within single compound classes. The obtained odor reduction strategies not only promote the deodorization of HDPE-lignin blends, but might be additionally helpful for the odor optimization of other natural-fiber based materials. Full article
(This article belongs to the Special Issue Biobased and Biodegradable Polymer Blends and Composites)
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17 pages, 2472 KiB  
Article
Optimal Design of Wood/Rice Husk-Waste-Filled PLA Biocomposites Using Integrated CRITIC–MABAC-Based Decision-Making Algorithm
by Tej Singh, Punyasloka Pattnaik, Amit Aherwar, Lalit Ranakoti, Gábor Dogossy and László Lendvai
Polymers 2022, 14(13), 2603; https://0-doi-org.brum.beds.ac.uk/10.3390/polym14132603 - 27 Jun 2022
Cited by 8 | Viewed by 1770
Abstract
Based on the criteria importance through inter-criteria correlation (CRITIC) and the multi-attributive border approximation area comparison (MABAC), a decision-making algorithm was developed to select the optimal biocomposite material according to several conflicting attributes. Poly(lactic acid) (PLA)-based binary biocomposites containing wood waste and ternary [...] Read more.
Based on the criteria importance through inter-criteria correlation (CRITIC) and the multi-attributive border approximation area comparison (MABAC), a decision-making algorithm was developed to select the optimal biocomposite material according to several conflicting attributes. Poly(lactic acid) (PLA)-based binary biocomposites containing wood waste and ternary biocomposites containing wood waste/rice husk with an overall additive content of 0, 2.5, 5, 7.5 and 10 wt.% were manufactured and evaluated for physicomechanical and wear properties. For the algorithm, the following performance attributes were considered through testing: the evaluated physical (density, water absorption), mechanical (tensile, flexural, compressive and impact) and sliding wear properties. The water absorption and strength properties were found to be the highest for unfilled PLA, while modulus performance remained the highest for 10 wt.% rice husk/wood-waste-added PLA biocomposites. The density of PLA biocomposites increased as rice husk increased, while it decreased as wood waste increased. The lowest and highest density values were recorded for 10 wt.% wood waste and rice husk/wood-waste-containing PLA biocomposites, respectively. The lowest wear was exhibited by the 5 wt.% rice husk/wood-waste-loaded PLA biocomposite. The experimental results were composition dependent and devoid of any discernible trend. Consequently, prioritizing the performance of PLA biocomposites to choose the best one among a collection of alternatives became challenging. Therefore, a decision-making algorithm, called CRITIC–MABAC, was used to select the optimal composition. The importance of attributes was determined by assigning weight using the CRITIC method, while the MABAC method was employed to assess the complete ranking of the biocomposites. The results achieved from the hybrid CRITIC–MABAC approach demonstrated that the 7.5 wt.% wood-waste-added PLA biocomposite exhibited the optimal physicomechanical and wear properties. Full article
(This article belongs to the Special Issue Biobased and Biodegradable Polymer Blends and Composites)
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16 pages, 3644 KiB  
Article
Improvement of the PLA Crystallinity and Heat Distortion Temperature Optimizing the Content of Nucleating Agents and the Injection Molding Cycle Time
by Laura Aliotta, Letizia Maria Sciara, Patrizia Cinelli, Ilaria Canesi and Andrea Lazzeri
Polymers 2022, 14(5), 977; https://0-doi-org.brum.beds.ac.uk/10.3390/polym14050977 - 28 Feb 2022
Cited by 26 | Viewed by 3201
Abstract
Three different commercial nucleating agents (LAK, talc, and calcium carbonate) were added at different weight percentages into poly (lactic acid) (PLA) in order to investigate the mechanical and thermo-mechanical behavior of blends in correlation to injection molding parameters. After as-sessing the best content [...] Read more.
Three different commercial nucleating agents (LAK, talc, and calcium carbonate) were added at different weight percentages into poly (lactic acid) (PLA) in order to investigate the mechanical and thermo-mechanical behavior of blends in correlation to injection molding parameters. After as-sessing the best content of each nucleating agent, analyzing isothermal and non-isothermal crys-tallization, two cycle times that can be industrially adopted were selected. Crystallinity highly impacts the flexural modulus, while it improves the heat deflection temperature only when the crystallinity percentage is above 50%; nevertheless, an excessive crystallinity content leads to a decrement of impact resistance. LAK does not appear to be sensitive to cycle time while talc and calcium carbonate proved to be effective if a cycle time of 60 s is adopted. Since the choice of nu-cleating agent is not univocal, the identification of the best nucleating agents is subject to the technical specifications required by the application, accotuing for the most important commercial requirements (productivity, temperature, and impact resistance). Full article
(This article belongs to the Special Issue Biobased and Biodegradable Polymer Blends and Composites)
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17 pages, 7142 KiB  
Article
Poly-ε-Caprolactone/Halloysite Nanotube Composites for Resorbable Scaffolds: Effect of Processing Technology on Homogeneity and Electrospinning
by Muriel Józó, Róbert Várdai, Nóra Hegyesi, János Móczó and Béla Pukánszky
Polymers 2021, 13(21), 3772; https://0-doi-org.brum.beds.ac.uk/10.3390/polym13213772 - 31 Oct 2021
Viewed by 1337
Abstract
Polycaprolactone (PCL)/halloysite composites were prepared to compare the effect of homogenization technology on the structure and properties of the composites. Halloysite content changed from 0 to 10 vol% in six steps and homogeneity was characterized by various direct and indirect methods. The results [...] Read more.
Polycaprolactone (PCL)/halloysite composites were prepared to compare the effect of homogenization technology on the structure and properties of the composites. Halloysite content changed from 0 to 10 vol% in six steps and homogeneity was characterized by various direct and indirect methods. The results showed that the extent of aggregation depends on technology and on halloysite content; the size and number of aggregates increase with increasing halloysite content. Melt mixing results in more homogeneous composites than the simple compression of the component powders or homogenization in solution and film casting. Homogeneity and the extent of aggregation determines all properties, including functionality. The mechanical properties of the polymer deteriorate with increasing aggregation; even stiffness depends on homogeneity. Strength and deformability decreases drastically as the number and size of aggregates increase. Not only dispersed structure, but also the physical state and crystalline structure of the polymer influence homogeneity and properties. The presence of the filler affects the preparation of electrospun fiber scaffolds as well. A part of the filler is excluded from the fibers while another part forms aggregates that complicates fiber spinning and deteriorates properties. The results indicate that spinning is easier and the quality of the fibers is better if a material homogenized previously by melt mixing is used for the production of the fibers. Full article
(This article belongs to the Special Issue Biobased and Biodegradable Polymer Blends and Composites)
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Review

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23 pages, 4805 KiB  
Review
A Brief Review of Poly (Butylene Succinate) (PBS) and Its Main Copolymers: Synthesis, Blends, Composites, Biodegradability, and Applications
by Laura Aliotta, Maurizia Seggiani, Andrea Lazzeri, Vito Gigante and Patrizia Cinelli
Polymers 2022, 14(4), 844; https://0-doi-org.brum.beds.ac.uk/10.3390/polym14040844 - 21 Feb 2022
Cited by 108 | Viewed by 13482
Abstract
PBS, an acronym for poly (butylene succinate), is an aliphatic polyester that is attracting increasing attention due to the possibility of bio-based production, as well as its balanced properties, enhanced processability, and excellent biodegradability. This brief review has the aim to provide the [...] Read more.
PBS, an acronym for poly (butylene succinate), is an aliphatic polyester that is attracting increasing attention due to the possibility of bio-based production, as well as its balanced properties, enhanced processability, and excellent biodegradability. This brief review has the aim to provide the status concerning the synthesis, production, thermal, morphological and mechanical properties underlying biodegradation ability, and major applications of PBS and its principal copolymers. Full article
(This article belongs to the Special Issue Biobased and Biodegradable Polymer Blends and Composites)
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