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Purpose: To assess the healing process of the extraction socket and the dimensional changes that occur after alveolar ridge preservation utilizing a polylactide-co-glycolide scaffold (PLGA). Materials and Methods: The present study involved the extraction of 28 teeth from 14 patients. The total number of sockets was 28, which were divided into two groups consisting of 14 test sockets and 14 control sockets. The study group (SG) was subjected to socket preservation with a PLGA scaffold while the control group (CG) was left for spontaneous healing. The dimensions were measured before and after operation at 1, 3, and 5 mm below the alveolar crest horizontally and the height of buccolingual bone vertically. Results: According to the histologic analyses, the PLGA scaffold was resorbed within 4 months. CBCT imaging revealed a decrease in the horizontal crest dimension at three distinct coronoapical levels in SG, measuring 2.05 ± 1.05 mm at -1 mm, 1.51 ± 0.89 mm at -3 mm, and 0.92 ± 0.7 mm at -5 mm. CG showed readings of 1.22 ± 1 at -1 mm, 0.92 ± 0.67 at -3 mm, and 0.73 ± 0.69 at -5 mm. In comparison to CG, SG showed a significant reduction in horizontal losses at -1 mm. Vertical crest dimensions decreased by 1.64 ± 1.11 mm for the buccal bone height and by 1.56 ± 1.08 mm for lingual bone height in SG; in CG, the buccal and lingual bone height had mean values of 2.08 ± 1.44 mm and 1.73 ± 1.27 mm, respectively. There was no statistically significant difference observed in the vertical losses between the groups. Conclusions: Following a period of 4 months, the PLGA scaffold was completely resorbed. Based on CBCT measurements, horizontal resorption was lower than CG at -1 mm coronally. [ABSTRACT FROM AUTHOR]

UNLABELLED: Biodegradable plastics are urgently needed to replace petroleum-derived polymeric materials and prevent their accumulation in the environment. To this end, we isolated and characterized a halophilic and alkaliphilic bacterium from the Great Salt Lake in Utah. The isolate was identified as a Halomonas species and designated CUBES01. Full-genome sequencing and genomic reconstruction revealed the unique genetic traits and metabolic capabilities of the strain, including the common polyhydroxyalkanoate (PHA) biosynthesis pathway. Fluorescence staining identified intracellular polyester granules that accumulated predominantly during the strains exponential growth, a feature rarely found among natural PHA producers. CUBES01 was found to metabolize a range of renewable carbon feedstocks, including glucosamine and acetyl-glucosamine, as well as sucrose, glucose, fructose, and further glycerol, propionate, and acetate. Depending on the substrate, the strain accumulated up to ~60% of its biomass (dry wt/wt) in poly(3-hydroxybutyrate), while reaching a doubling time of 1.7 h at 30°C and an optimum osmolarity of 1 M sodium chloride and a pH of 8.8. The physiological preferences of the strain may not only enable long-term aseptic cultivation but also facilitate the release of intracellular products through osmolysis. The development of a minimal medium also allowed the estimation of maximum polyhydroxybutyrate production rates, which were projected to exceed 5 g/h. Finally, also, the genetic tractability of the strain was assessed in conjugation experiments: two orthogonal plasmid vectors were stable in the heterologous host, thereby opening the possibility of genetic engineering through the introduction of foreign genes. IMPORTANCE: The urgent need for renewable replacements for synthetic materials may be addressed through microbial biotechnology. To simplify the large-scale implementation of such bio-processes, robust cell factories that can utilize sustainable and widely available feedstocks are pivotal. To this end, non-axenic growth-associated production could reduce operational costs and enhance biomass productivity, thereby improving commercial competitiveness. Another major cost factor is downstream processing, especially in the case of intracellular products, such as bio-polyesters. Simplified cell-lysis strategies could also further improve economic viability.

Given the multitude of extracellular enzymes at their disposal, many of which are designed to degrade natures polymers (lignin, cutin, cellulose, etc.), fungi are adept at targeting synthetic polyesters with similar chemical composition. Microbial-influenced deterioration of xenobiotic polymeric surfaces is an area of interest for material scientists as these are important for the conservation of the underlying structural materials. Here, we describe the isolation and characterization of the Papiliotrema laurentii 5307AH (P. laurentii) cutinase, Plcut1. P. laurentii is basidiomycete yeast with the ability to disperse Impranil-DLN (Impranil), a colloidal polyester polyurethane, in agar plates. To test whether the fungal factor involved in this clearing was a secreted enzyme, we screened the ability of P. laurentii culture supernatants to disperse Impranil. Using size exclusion chromatography (SEC), we isolated fractions that contained Impranil-clearing activity. These fractions harbored a single ~22 kD band, which was excised and subjected to peptide sequencing. Homology searches using the peptide sequences identified, revealed that the protein Papla1 543643 (Plcut1) displays similarities to serine esterase and cutinase family of proteins. Biochemical assays using recombinant Plcut1 confirmed that this enzyme has the capability to hydrolyze Impranil, soluble esterase substrates, and apple cutin. Finally, we confirmed the presence of the Plcut1 in culture supernatants using a custom antibody that specifically recognizes this protein. The work shown here supports a major role for the Plcut1 in the fungal degradation of natural polyesters and xenobiotic polymer surfaces.IMPORTANCEFungi play a vital role in the execution of a broad range of biological processes that drive ecosystem function through production of a diverse arsenal of enzymes. However, the universal reactivity of these enzymes is a current problem for the built environment and the undesired degradation of polymeric materials in protective coatings. Here, we report the identification and characterization of a hydrolase from Papiliotrema laurentii 5307AH, an aircraft-derived fungal isolate found colonizing a biodeteriorated polymer-coated surface. We show that P. laurentii secretes a cutinase capable of hydrolyzing soluble esters as well as ester-based compounds forming solid surface coatings. These findings indicate that this fungus plays a significant role in biodeterioration through the production of a cutinase adept at degrading ester-based polymers, some of which form the backbone of protective surface coatings. The work shown here provides insights into the mechanisms employed by fungi to degrade xenobiotic polymers.

The performance of sustainable polymers can be modified and enhanced by incorporating functional groups in the backbone of the polymer chain that increases intermolecular interactions, thus impacting the thermal properties of the material. However, in-depth studies on the role of intermolecular interactions on the crystallization of these polymers are still needed. This work aims to ascertain whether incorporating functional groups able to induce intermolecular interactions can be used as a suitable systematic strategy to modify the polymer thermal properties and crystallization kinetics. Thus, amide and additional ester groups have been incorporated into aliphatic polyesters (PEs). The impact of intermolecular interactions on the melting and crystallization behavior, crystallization kinetics, and crystalline structure has been determined. Functional groups that form strong intermolecular interactions increase both melting and crystallization temperatures but retard the crystallization kinetics. Selecting appropriate functional groups allows tuning the crystallinity degree, which can potentially improve the mechanical properties and degradability in semicrystalline materials. The results demonstrate that it is possible to tune the thermal transitions and the crystallization kinetics of PEs independently by varying their chemical structure. [ABSTRACT FROM AUTHOR]

This study introduces phthalic anhydride (P) and glycerol (G)‐based polyester as an additive for upgrading lower‐grade bitumen to higher‐grade bitumen. The different colorless polyesters were synthesized using polycondensation of P and G as a monomer in the ratio of 1:1 and polymerization time of 1, 3, 5, and 7 h. A rheological analysis was performed on all the synthesized polyesters to check their performance with respect to their use in bitumen modification. The polyesters were blended with base bitumens (VG10) to obtain the modified bitumens that were tested for the rheological and physicochemical properties and to assess the performance based on the grade quality test. The quality test of the modified bitumens includes softening point (SP), penetration (PEN), kinematic viscosity (KV), dynamic viscosity (DV), and rheological properties as per standard ASTM test methods. Based on the performance evaluation, P1G1H3 polyester was found suitable for blending with bitumen, and further study was carried out with blending of P1G1H3 with 3, 6, 10, and 15 wt%. The finding illustrates that 6.0 wt% of polyester‐modified bitumen show an enhanced SP, KV, and DV by 23.6, 86, and 30%, respectively, while decreasing the PEN by 49% with respect to VG10. Polyester blending also improved the rheological parameters in terms of deformation resistance, load‐bearing capacity, and the viscoelastic nature of bitumen. The investigation concluded that 6 wt% P1G1H3 polyester on blending in VG10 meets VG30 bitumen specification as per IS:73:2013. [ABSTRACT FROM AUTHOR]

The application and promotion of biodegradable plastics are hindered by the imbalance between their mechanical and degradation performance imbalance, as well as high costs. Herein, a series of poly(ethylene adipate‐co‐terephthalate) (PEAT) copolyesters with excellent mechanical and degradation properties are synthesized by one‐step melt polycondensation. The influence of the proportion of aliphatic groups in the molecular chain on the structure and properties, especially the degradation performance, of the copolyesters was studied. The molecular chain flexibility and degradability of PEAT increases with increasing of adipic acid content and decreasing of ET fragment length (LET). The comprehensive mechanical properties of PEAT60 can be comparable to traditional packaging material poly(butylene adipateco‐terephthalate) (PBAT). The degradation performance of PEAT can be adjusted the molecular chain structure. PEAT with LET < 3 exhibit degradation performance, and PEAT with LET < 2.2 exhibit significant degradation acceleration. The excellent mechanical and degradable properties of PEAT copolyester make it expected to be used in degradable packaging and other fields to help solve plastic pollution, while its lower cost will aid in the promotion of degradable materials. [ABSTRACT FROM AUTHOR]

In the present work, N-substituted glutamic acid, polyethylene and polypropylene glycols have been used to design biocompatible copolyesters via Steglich reactions. Due to the presence of alternating hydrophilic and hydrophobic blocks in their structures, these copolyesters are able to form self-stabilized nanoparticle dispersions in aqueous media. The lipophilic core of these nanoparticles can solubilize poorly water-soluble compounds and release them into a model of lipids in a human body. Moreover, the obtained copolyesters possess no cytotoxic effects over a wide concentration range. Thus, we conclude that obtained copolyesters show significant promise for further development as drug delivery systems. [ABSTRACT FROM AUTHOR]

In response to the health and environmental concerns associated with the plasticizer dioctyl phthalate (DOP), this research explores the utilization of methyl oleate (MO) derived from plant oil, 1,2,4‐Benzeneticarboxylic anhydride (TMA) and isobutyric anhydride (IA) as a precursor for synthesizing a hyperbranched polyester named IA‐MO‐TMA. This polyester serves as an alternative plasticizer for Polyvinyl chloride (PVC). The chemical structure of IA‐MO‐TMA was thoroughly characterized using Fourier Transform Infrared Spectrometer (FTIR) and nuclear magnetic resonance hydrogen spectra, and its molecular weight was assessed. The PVC film, plasticized with IA‐MO‐TMA, underwent comprehensive testing using techniques such as differential scanning calorimetry, scanning electron microscopy, and thermogravimetric analysis. Notably, the glass transition temperature (Tg) of the plasticized PVC film exhibited a significant reduction from 75°C to −6.7°C. The plasticized film demonstrated an elongation at break of 318.1%, a tensile strength of 19.2 MPa, and a plasticizing efficiency of 109.9%. Moreover, the use of IA‐MO‐TMA as a plasticizer increased the initial decomposition temperature of PVC film from 235.6 to 264.1°C. Additionally, the extraction rate of IA‐MO‐TMA in petroleum ether was found to be 35.6% lower than that of DOP. [ABSTRACT FROM AUTHOR]

A material capable of curing due to UV irradiation based on an alkyd oligomer and oligoorganosilsesquioxanes (OOSs) with functional thiol groups was obtained. Using microinterferometry, it was shown that the alkyd oligomer and OOS are completely compatible (mutually soluble). The resulting alkyd‐siloxane composition was cured under the action of UV irradiation due to reaction between double bonds of alkyd oligomer and thiol‐groups of silsesquioxane oligomer. The curing reaction takes 5 min with formation of coating, containing 99% of gel fraction, which is in 30 times faster in comparison with the classical method of alkyd curing in the presence of siccatives. The hydrophobicity of alkyd‐siloxane coatings also increases and varies depending on the content of OOS. The introduction of 50% OOS into the alkyd oligomer makes it possible to increase the water contact angle by 10° relative to the coating based on pure alkyd. A similar dependence is observed when studying the thermal stability of coatings. Thus, even with the introduction of 10% OOS into alkyd oligomer, the temperature at which a loss of 50% of mass occurs increases by 24°C relative to coatings based on a pure alkyd oligomer. [ABSTRACT FROM AUTHOR]

With the increasing emphasis on environmental protection, there is a growing focus on the synthesis of water‐solvent self‐emulsifying sizing agents. In this study, five types of anionic polyester sizing agents with varying molecular weights were synthesized to explore the effect of molecular weight on the interfacial bonding strength of carbon fiber (CF) reinforced vinyl resin composites. The results demonstrated that the molecular weights of the synthesized sizing agents were precise; the particles in the sizing agents were nanometer‐sized, monodisperse, and exhibited high thermal stability. When the molecular weight was 8000, it exhibited optimal wettability for CF, leading to a substantial improvement in the interlaminar shear strength, reaching 71.8 MPa, which represents a significant increase of 22.7% compared with commercial CFs (CFF). Additionally, the interfacial shear strength was maximized at 13.23 MPa, which was significantly increased by 14.2% compared with CCF. These significant improvements in surface properties and mechanical performance were attributed to the excellent wettability of the CF surface, effective spreading performance of the sizing agent, the presence of double bonds in the sizing agent facilitating reactions with free radicals on the CF surface, and the residual double bonds further undergoing curing with the vinyl resin, promoting the reinforcement of interface bonding. [ABSTRACT FROM AUTHOR]

The application properties such as foam property, electrolyte tolerance, antibacterial activity and antistatic performance of the mixed systems of a novel Gemini quaternary ammonium salt with quadra‐cationic sites (TC‐GS) and sodium fatty alcohol polyoxyethylene ether carboxylate (AE9CNa) at various molar fraction of TC‐GS (αTC‐GS), were investigated systematically. Results show that TC‐GS/AE9CNa mixed systems with different ratios form a homogeneous and transparent solution, which exhibits excellent foam stability and antibacterial activity. The foam volume of the mixed system remains nearly constant from 400 s to 1000 s, and even when TC‐GS is 10 mg/L in the mixed systems, the antibacterial rates against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) for 2 min. are all exceeded 99 %. The mixed systems of TC‐GS/AE9CNa at various αTC‐GS also demonstrate the superior electrolyte tolerance, their maximum tolerance of NaCl, CaCl2 and MgCl2 is severally beyond 270 g/L, 180 g/L and 180 g/L. In addition, both TC‐GS solution and the mixed systems have good antistatic properties, which can reduce the surface resistance of polyester fabric to ≤1010 Ω. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study is to check the effectivity of plasma in the natural dyeing of polyester fabric using four natural dyes – Turkey red, Lac, Turmeric and Catechu using plasma and alum mordant. The surface modification on the polyester fabric by plasma along with the use of benign mordant alum is studied. The enhancement of dyeability in polyester fabric with natural dyes is the main focus. Due to surface modification, the wettability increases, which leads to better dye uptake. Better dye uptake and better dye adherence are the main objectives. Design/methodology/approach: Plasma-mediated natural dyeing is the main design of this research work. The effect of plasma treatment on surface modification of synthetic fabric polyester and its subsequent effects on their dyeing with different natural dyes, namely, Turkey red, Lac, Turmeric and Catechu are studied. The dyeability was further enhanced by the use of alum as mordant. The main focus is on the betterment of natural dyeing of polyester fabric using sustainable natural dyes resources for dyeing and to reduce wastewater contamination from the usage of toxic additive chemicals for cleaner production. Findings: Plasma-mediated and alum-mordanted dyeing method facilitated very good dyeability of all the four natural dyes, namely, Turkey red, Lac, Turmeric and Catechu. Color strength (K/S) values and fastness properties of plasma-treated samples were far better than untreated samples. The synergistic effect of plasma and alum mordanting has made natural dyeing of polyester very easy with very good fastness results. Natural dyeing of polyester after 2 min of plasma treatment showed excellent and desirable results. The process is also easy to be adapted by industries. Research limitations/implications: As polyester is hydrophobic, natural dyeing of polyester fabric is not very easy, but with plasma-mediated natural dyeing, it becomes a very facile dyeing method; thus, there are no limitations. Use of plasma has reduced the need for any chemical additives which are usually added during the dyeing process. Practical implications: This process of natural dyeing of polyester fabric can be scaled up to industrial dyeing with natural dyes. Plasma pretreatment of the fabric followed by premordanting with alum has facilitated the natural dyeing well. Social implications: Use of plasma in place of chemical modifiers can be a green and environmentally friendly approach for sustainable coloration of polyester fabric, providing a clean wet processing for textiles dyeing. Originality/value: The synergistic effect of plasma-mediated and alum-mordanted natural dyeing of polyester has not been attempted by any researcher. To the best of the authors' knowledge, this is for the first time that pretreatment with atmospheric plasma followed by alum mordanting of polyester fabric has shown very good dye uptake and fastness properties as the dye molecules could penetrate well after 2 min of the plasma treatment. [ABSTRACT FROM AUTHOR]

Innovative and renewable polymers and additives are the focus of increased research due to public and environmental pressure. There has been a recent uptick in interest from scientists in biobased "green" plasticizers that can be covalently bonded to replace harmful and migratory phthalate‐based plasticizers. Vegetable oils (VOs) are one of the biosources, as they are both plentiful and sustainable. This review aims to highlight the synthesis methods for soy‐based polyesters. Therefore, the chemistry of soybean oil as a polymeric material and its role in the synthesis of polyesters derived from soybeans are the primary topics of this review. This review covers the many ways in which soybean oil and its derivatives can be used to synthesize polyester, either directly or indirectly. Highlights: The need for sustainable polymers is explored.Soybean oil‐based polyesters are covered.Modification and chemistry to convert soybean oil into polyester are described.Applications of soybean‐based polyesters are provided. [ABSTRACT FROM AUTHOR]

This study explores the stiffness enhancement in textile composites using four different fiber types: carbon, Kevlar, Vectran, and high-tenacity polyester (HTP). Pretension levels of 0.2, 2, 5, and 10 N were applied. A setup was developed to measure fiber stiffness. Results indicate that carbon fiber consistently demonstrates the highest stiffness across all pretenstionlevels, attributable to its high tensile strength and modulus. Kevlar fiber, although initially less stiff than carbon, exhibits the most substantial increase in stiffness, particularly between 5 and 10 N of pretension, reaching a peak stiffness of 33.8 at 10 N. Vectran fiber shows a gradual increase in stiffness, surpassing HTP but slightly lagging behind carbon and Kevlar. The rates of yarn-specific bending stiffness increase were measured as 0.168 for HTP, 0.054 for carbon fiber, 0.173 for Kevlar fiber, and 0.191 for Vectran fiber. The study highlights the importance of understanding how yarn pretension affects the bending stiffness of yarn-polymer composites, which is crucial for advancements in textile engineering. It was found that variations in the bending stiffness of HTP and carbon fibers significantly impacted the composite bending stiffness more than Vectran and Kevlar fibers under pretension during composite formation. High-stiffness yarns were less influenced by increasing pretension during composite fabrication. The study suggests utilizing yarn pretension to control the stiffness of textile/polymer composites and proposes individually tensioning and pultruding fibers or yarns in the polymer matrix before composite formation. A specialized setup for achieving this during the protrusion process is recommended. [ABSTRACT FROM AUTHOR]

Polypropylene carbonate (PPC) is a biodegradable polyester with excellent toughness and ductility that may be employed as carbon fixation materials in biomedicine, agriculture, and environmental engineering. However, relatively lower strength and poor dimensional stability hinder its extensive application. In this study, nanofibrillated cellulose (NFC) and chitosan (CS) were introduced as biobased reinforcements into PPC without compromising its biodegradability. Notably, the composites not only had improved strength but also enhanced toughness after the addition of NFC and CS. The tensile strength and Young's modulus were increased by 25% and 58% in the composites with 3 wt% NFC and 2 wt% CS additions compared to pure PPC. Interestingly, the PPC/NFC/CS composites exhibited superior dimensional stability and antibacterial property. Upon the addition of 3 wt% NFC and 2 wt% CS, the composites took 3 s recovering from 0° to 137°. Additionally, NFC and CS contribute to the hydrophilicity of PPC composites. These findings offer valuable insights into experimental data and preparation techniques to the utilization of PPC in engineering fields. Highlights: The developed composites achieved maximum tensile strength (13.5 MPa).The composites with 2 wt% chitosan had effective antibacterial properties.All reinforced composites showed excellent dimensional stability.Nanofibrillated cellulose and chitosan had toughening and enhancing effect.The developed composites showed good hydrophilicity. [ABSTRACT FROM AUTHOR]

Highlights This study reports the test results of a total of 16 low‐voltage (415 V) 15 and 30 kVA alternators manufactured using optimized polyester resin nanocomposites. These tests consist of the open‐circuit characteristics (OCC), short‐circuit characteristics (SCC), voltage regulation, and temperature rise tests. The test results obtained are reported in terms of efficiency, voltage regulation, OCC and SCC curves, and temperature rise in stator and rotor windings. The results show that the temperature rise in the windings reduced significantly and the efficiency improved marginally using polyester resin nanocomposite insulation. Finally, the calculations show that the reduction in temperature rise can double the life of the alternator. Notably, the manufactured alternators passed all the performance tests as per the test standards, without adversely affecting its performance. For the insulation design of any low‐voltage rotating machine utilizing polyester resin as its base insulation, a similar approach can thus be adopted. Fabrication of alternator prototype using polyester nanocomposite insulation. Alternator prototype fabrication using standard industry manufacturing process. Reduction in temperature rise in stator and rotor windings by 10 °C. Enhancement in alternator efficiency by 3%–4%. Polyester nanocomposite insulation doubles the service life of alternator. [ABSTRACT FROM AUTHOR]

The development of multifunctional bio‐based materials with closed‐loop chemically recyclable plastics can be a paramount response to the worldwide plastic waste predicament. However, the trade‐off dilemma between the high performance and easy recycling performance of these materials still encounters huge challenges. In this contribution, inspired by the significant contribution of the hydrogen bonding networks to enhanced mechanical and gas barrier performance as well as the cosolvents to enhance recycling performance, a novel polyester material (PBHyF) synthesized by bio‐based monomers that integrate high‐performance and efficient chemical closed‐loop is presented. PBHyF show ultra‐high mechanical properties (83.2 MPa, 233.9%) and barrier properties (CO2 0.0157 barrer, O2 0.0071 barrer, H2O 5.518E‐15 g·cm/cm2·s·Pa) that are greater than bio‐based materials and most engineering plastics of previous work. More significantly, PBHyF also exhibits multifunctionality with excellent ultraviolet shielding properties, solvent‐resistant properties, and easy recycling performance. The initial monomers of PBHyF can be obtained in exceptional yields (>90.0%) and purity (>99.0%) under mild conditions by a simple energy‐efficient rapid chemical‐solvolysis strategy, even with polyolefin blend plastics. Further possesses similar high‐performance repolymerized polyester comparable to the polyester before recycling. Hence, these state‐of‐art high‐performance and easy‐recycling bio‐based materials provide a new approach for a green, sustainable material economy. [ABSTRACT FROM AUTHOR]

This study investigates the wash resistance of polyester fabrics functionalized with chitosan, a biopolymer known for its biocompatibility, non-toxicity, biodegradability and environmentally friendly properties. The interaction of chitosan with synthetic polymers, such as polyester, often requires surface treatment due to the weak natural affinity between the two materials. To improve the interaction and stability of chitosan on polyester, alkaline hydrolysis of the polyester fabric was used as a surface treatment method. The effectiveness of using cross-linking agents 1,2,3,4-butane tetracarboxylic acid (BTCA) and hydroxyethyl methacrylate (HEMA) in combination with ammonium persulphate (APS) to improve the stability of chitosan on polyester during washing was investigated. The wash resistance of polyester fabrics functionalized with chitosan was tested after 1, 5 and 10 washes with a standard ECE detergent. Staining tests were carried out to evaluate the retention of chitosan on the fabric. The results showed that polyester fabrics functionalized with chitosan without cross-linkers exhibited better wash resistance than the fabrics treated with crosslinkers. [ABSTRACT FROM AUTHOR]

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is a very promising biodegradable copolyester of high interest in food packaging. Its inherent brittleness and narrow processing window make it necessary to blend it with flexible biopolyesters, such as poly(butylene succinate-co-adipate) (PBSA). However, the resultant biopolyester blends are thermodynamically immiscible, which impairs their performance and limits their applications. This study is the first to explore the use of poly(butylene succinate-co-adipate) grafted with maleic anhydride (PBS-g-MAH) as a novel reactive additive to compatibilize PHBV/PBSA blends. The compatibilizer was prepared by a reactive melt-mixing process of PBSA and maleic anhydride (MAH) using dicumyl peroxide (DCP) as an organic radical initiator, achieving a grafting degree (Gd) of 5.4%. Biopolyester blend films were thereafter prepared via cast extrusion and their morphological, thermal, mechanical, and barrier properties were characterized. Compatibilization by PBSA-g-MAH was confirmed by observing an improved phase interaction and lower dispersed domain sizes in the blends with 15 wt% PBSA. These compatibilized PHBV/PBSA blends were thermally stable up to 285 °C, showed enhanced ductility and toughness, as well as providing an improved barrier against water and limonene vapors and oxygen. These findings suggest that the use of MAH-grafted biopolyesters can represent an effective strategy to improve the properties of biopolyester blends and open up new opportunities for the application of PHBV-based formulations for food packaging. [ABSTRACT FROM AUTHOR]

Two biodegradable polyesters, poly(butylene succinate) (PBS) and poly(butylene succinate‐co‐adipate) (PBSA), were artificially aged in a UV irradiation test chamber, and their photodegradation behaviors investigated. The attenuated total reflection (ATR) infrared (IR) spectra of the initial and UV‐aged samples revealed conformational changes in the tetramethylene sequences of the photoaged PBS and PBSA. The one‐dimensional wide‐angle X‐ray scattering (WAXS) profiles showed that the (110) d‐spacing of the α‐form crystal progressively decreased during UV aging, suggesting that the crystalline polymer chains became arranged more closely along the fiber axis. Accordingly, we conclude that PBS and PBSA transform from their TGTGT to nearly TTTTT conformations upon photoaging. The observed WAXS, small‐angle X‐ray scattering, and IR spectral data suggest that photodegradation preferentially occurs in the amorphous phase of each polymer. The less crystallizable butylene adipate co‐unit enhances the degradability of PBSA, with prolonged photooxidation leading to partial degradation of the crystalline region of the copolymer. This finding is consistent with and may be linked to the higher biodegradability of PBSA compared to PBS. [ABSTRACT FROM AUTHOR]

Cyclic ketene acetals (CKAs) possess unique features in two aspects. On one hand, after the addition of a radical on the alkene, CKAs can undergo ring‐opening via radical rearrangement, enabling polyester preparation based on chain‐growth polymerization. On the other hand, the alkene connected with two electron‐donating oxygens in a strained form exhibit unique reactivities, resulting in complex reactions in the presence of electron deficient compounds. In this investigation, fundamental studies on CKA radical ring‐opening polymerization and charge‐mediated reactions were performed. Alternating copolymers of CKA and maleimides, or maleates, were prepared and characterized. Quantum chemistry modeling from the perspectives of reaction kinetics and thermodynamics enabled an in‐depth mechanistic study on the side reactions between CKA and maleic anhydride or itaconic anhydride, inspiring the techniques to minimize those side reactions in competition with radical copolymerization. After purifying the anhydride monomers with sublimation, the copolymerization with CKA successfully occurred. The anhydride containing polyester structures with an alternating sequence were confirmed with comprehensive characterizations. Facile post‐functionalization with an alcohol was performed, resulting in carboxylate containing polyesters. [ABSTRACT FROM AUTHOR]

Developing eco-friendly polymeric plasticizers with excellent migration resistance is one of the research hotspots in the polyvinyl chloride (PVC) industry. A low-molecular-weight biobased polyester rubber (LMW-BPR) was synthesized from five biobased polyester monomers in a 100-L reactor and evaluated as a potential eco-friendly polymeric plasticizer for PVC. The obtained LMW-BPR is an amorphous polyester material with a low glass transition temperature of -48°C and a molecular weight of 22 kg/mol, which is lower than that of existing polyester rubber but higher than those of most polyester plasticizer commodities. Plasticized PVC composites with a total plasticizer content of 50 phr were prepared by using the mixture of LMW-BPR and di-isononyl cyclohexane-1,2-dicarboxylate (DINCH, an eco-friendly monomeric plasticizer commodity) as the plasticizer. The migration resistance test showed that the migration loss of plasticizer in plasticized PVC composite decreased significantly with the increase of LMW-BPR content. When the content of LMW-BPR reaches 30 phr, the plasticized PVC composites are almost nonmigratory. In addition, compared with PVC composite plasticized by pure DINCH, co-plasticized PVC composites containing LMW-BPR exhibit higher tensile strength and thermal stability, and their flexibility, low-temperature resistance and biocompatibility are also maintained at a similar level to the former. Overall, LMW-BPR is an effective eco-friendly polymeric plasticizer for PVC and also sustainable and scalable, thus it is worthy of wide application. [ABSTRACT FROM AUTHOR]

Monodomain liquid crystal elastomers (LCEs) are prepared using liquid crystal block copolymers (LCBCPs) comprised of a nematic liquid crystal (NLC) main‐chain polyester linked to cross‐linkable polymethacrylate (PMA) at both ends. LCBCPs at a PMA weight fraction of ≈30% are doped with a tetra‐thiol compound, stretched in one direction, and then illuminated by UV light, yielding LCBCPs that formed microlamellae consisting of alternate stacking crosslinked PMA blocks and NLC polyester blocks. The LC director lay along the stretching direction (SD). Raising the temperature to the NLC isotropization temperature, the crosslinked LCBCP strips fixed at one end contracted reversibly by a factor of 1.2–1.4 along the SD, deforming the microlamellae. The strips fixed at both ends increased the tensile stress to ≈200 kPa while maintaining the microlamellae undeformed. Regardless of strip fixation at one or both ends, the NLC decreased the orientational order. The contraction amounts and the tensile stress of strips are well associated with decreased NLC orientational order. [ABSTRACT FROM AUTHOR]

Blood vessels are highly dynamic and complex structures with a variety of physiological functions, including the transport of oxygen, nutrients, and metabolic wastes. Their normal functioning involves the close and coordinated cooperation of a variety of cells. However, adverse internal and external environmental factors can lead to vascular damage and the induction of various vascular diseases, including atherosclerosis and thrombosis. This can have serious consequences for patients, and there is an urgent need for innovative techniques to repair damaged blood vessels. Polyesters have been extensively researched and used in the treatment of vascular disease and repair of blood vessels due to their excellent mechanical properties, adjustable biodegradation time, and excellent biocompatibility. Given the high complexity of vascular tissues, it is still challenging to optimize the utilization of polyesters for repairing damaged blood vessels. Nevertheless, they have considerable potential for vascular tissue engineering in a range of applications. This summary reviews the physicochemical properties of polyhydroxyalkanoate (PHA), polycaprolactone (PCL), poly-lactic acid (PLA), and poly(lactide-co-glycolide) (PLGA), focusing on their unique applications in vascular tissue engineering. Polyesters can be prepared not only as 3D scaffolds to repair damage as an alternative to vascular grafts, but also in various forms such as microspheres, fibrous membranes, and nanoparticles to deliver drugs or bioactive ingredients to damaged vessels. Finally, it is anticipated that further developments in polyesters will occur in the near future, with the potential to facilitate the wider application of these materials in vascular tissue engineering. [ABSTRACT FROM AUTHOR]

The biocatalytic degradation of poly(ethylene terephthalate) (PET) through enzymatic methods has garnered considerable attention due to its environmentally friendly and non-polluting nature, as well as its high specificity. While previous efforts in enhancing IsPETase performance have focused on amino acid substitutions in protein engineering, we introduced an amino acid insertion strategy in this work. By inserting a negatively charged acidic amino acid, Glu, at the right-angle bend of IsPETase, the binding capability between the enzyme's active pocket and PET was improved. The resulted mutant IsPETase9394insE exhibited enhanced hydrolytic activity towards PET at various temperatures ranging from 30 to 45 ℃ compared with the wild-type IsPETase. Notably, a 10.04-fold increase was observed at 45 ℃. To further enhance PET hydrolysis, different carbohydrate-binding modules (CBMs) were incorporated at the C-terminus of IsPETase9394insE. Among these, the fusion of CBM from Verrucosispora sioxanthis exhibited the highest enhancement, resulting in a 1.82-fold increase in PET hydrolytic activity at 37 ℃ compared with the IsPETase9394insE. Finally, the engineered variant was successfully employed for the degradation of polyester filter cloth, demonstrating its promising hydrolytic capacity. In conclusion, this research presents an alternative enzyme engineering strategy for modifying PETases and enriches the pool of potential candidates for industrial PET degradation. [ABSTRACT FROM AUTHOR]

The synthesis of biobased polyesters based on 2,5-bis(hydroxymethyl)furan (BHMF) is challenging due to the limited stability of this interesting furanic monomer. In this work, a series of BHMF-based polyesters were produced via a green and efficient bulk polymerization process, by using either an enzyme (iCALB) or a commercially available catalyst (DBTO). The polymerization methods were compared and shown to both be successful, with values up to 14 000 g mol−1. The number of methylene units in the aliphatic comonomer was varied from 2 to 8, and the influence of this on the thermal behavior and stability of the polymers was investigated. The degree of crystallinity of compression molded discs was found to be in the range from 13 to 27%, and the contact angles were determined to be in the region from 63 to 73°, confirming that these polyesters are hydrophilic. An oscillatory shear rheology investigation demonstrated significant differences between the melt behavior of the BHMF-based polyesters, ranging from a Newtonian liquid to a shear thinning material with a 3 orders of magnitude higher complex viscosity. A clear inversely proportional correlation between the low-frequency complex viscosity and the number of methylene units in the aliphatic segment was observed. Finally, a biodegradability test revealed that the synthesized BHMF-based polyesters had a biodegradable character over time, wherein different biodegradation rates were observed related to the length of aliphatic segments in the repeating units. The sustainability of both synthesis routes was analyzed based on atom economy (AE), reaction mass efficiency (RME), E-factor and EcoScale. This work emphasizes that renewable BHMF-based polyesters can be produced via a solvent-free and sustainable process, which show biodegradable behavior and that their thermal and rheological properties can be tailored by varying the number of methylene groups in the aliphatic unit. [ABSTRACT FROM AUTHOR]

Synthesis of monomer‐recyclable polyesters solely from CO2 and bulk olefins holds great potential in significantly reducing CO2 emissions and addressing the issue of plastic pollution. Due to the kinetic disadvantage of direct copolymerization of CO2 and bulk olefins compared to homopolymerization of bulk olefins, considerable research attention has been devoted to synthesis of polyester via the ring‐opening polymerization (ROP) of a six‐membered disubstituted lactone intermediate, 1,2‐ethylidene‐6‐vinyl‐tetrahydro‐2H‐pyran‐2‐one (휹‐L), obtained from telomerization of CO2 and 1,3‐butadiene. However, the conjugate olefin on the six‐membered ring of 휹‐L leads to serious Michael addition side reactions. Thus, the selective ROP of 휹‐L, which can precisely control the repeating unit for the production of polyesters potentially amenable to efficient monomer recycling, remains an unresolved challenge. Herein, the first example of selective ROP of 휹‐L is reported using a combination of organobase and N,N′‐Bis[3,5‐bis(trifluoromethyl)phenyl]urea as the catalytic system. Systematic modifications of the substituent of the urea show that the presence of electron‐deficient 3,5‐bis(trifluoromethyl)‐phenyl groups is the key to the extraordinary selectivity of ring opening over Michael addition. Efficient monomer recovery of oligo(휹‐L) is also achieved under mild catalytic conditions. [ABSTRACT FROM AUTHOR]

While extensive research has explored the effects of plastic pollution, ecosystem responses remain poorly quantified, especially in field experiments. In this study, we investigated the impact of polyester pollution, a prevalent plastic type, on coastal sediment ecosystem function. Strips of polyester netting were buried into intertidal sediments, and effects on sediment oxygen consumption and polyester additive concentrations were monitored over 72-days. Our results revealed a rapid reduction in the magnitude and variability of sediment oxygen consumption, a crucial ecosystem process, potentially attributed to the loss of the additive di(2-ethylhexyl) phthalate (DEHP) from the polyester material. DEHP concentrations declined by 89% within the first seven days of deployment. However, effects on SOC dissipated after 22 days, indicating a short-term impact and a quick recovery by the ecosystem. Our study provides critical insights into the immediate consequences of plastic pollution on ecosystem metabolism in coastal sediments, contributing to a nuanced understanding of the temporal variation of plastic pollution's multifaceted impacts. Additionally, our research sheds light on the urgent need for comprehensive mitigation strategies to preserve marine ecosystem functionality from plastic pollution impacts. [ABSTRACT FROM AUTHOR]

A novel diphenyl monomer, dimethyl 2,2'-(((ethane-1,2-diylbis(oxy))bis(4-acetyl-3,1-phenylene))bis(oxy))diacetate (EDPD), was synthesized from methyl 2-(4-acetyl-3-hydroxyphenoxy)acetate (MAHA), a 2,4-dihydroxyacetophenonederivative, and combined with 1,4-butanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol or p-phenylenedimethanolto afford a series of biodegradable polyesters via melt polymerization. The polyesters were characterized by Fourier transform infrared and proton nuclear magnetic resonance spectroscopy, gel permeation chromatography, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The weight-average molecular weight (Mw) of the polyesters varied from 3.2–4.4 × 104 g/mol, the glass transition temperature (Tg) from 52 to 80 °C, and the 5% decomposition temperature (Td,5%) was in the 334–362 °C range. All the samples exhibited high yield strength (53–68 MPa) and elongation at break (230–330%) values, comparable with poly(ethylene terephthalate) (PET), owing to their aromatic character. Degradability testing of the polyesters in soil yielded mass losses reaching up to 7% after 32 weeks. In ecotoxicity testing, earthworms had a survival rate of more than 80% after 14 d of incubation, indicating relatively low toxicity. Overall, the good thermal and mechanical properties, biodegradability and low ecotoxicity of the polyesters make them promising materials for packaging applications, in replacement for PET, thereby promoting carbon neutrality and sustainable development. [ABSTRACT FROM AUTHOR]

Water pollution seriously affects the development of society and human life. There are various kinds of pollutants, including soluble pollutants and insoluble floaters on the water surface. Herein, the photocatalyst semiconductor BiOCl and superhydrophobic functional particles Mg(OH)2 were deposited on the surfaces of canvas and polyester felt to construct superhydrophobic canvas and polyester felt. The contact angles of the synthetic superhydrophobic canvas and polyester felt were measured as 152° and 155.3°, respectively. The selective adsorption of hexadecane was achieved using the wetting difference between the surface of water and pollutants floating on the surface. For dissolved pollutants, the surface wettability needed to be changed with the help of ethanol. The degradation efficiencies were all greater than 90%, demonstrating the versatility of the synthetic superhydrophobic canvas and polyester felt. [ABSTRACT FROM AUTHOR]

Two series of lactone-terminated alkanethiol adsorbates with five- and six-membered lactone groups, γ-COCnSH and δ-COCnSH (n = 11, 12), were synthesized and employed to create nanoscale self-assembled monolayers (SAMs) on gold substrates to mimic the properties of commercially available poly(lactic-co-glycolic acid) (PLGA) and poly(glycolic acid) (PGA) surfaces. 1H and 13C nuclear magnetic resonance (NMR) were employed to characterize the adsorbate molecules. The thicknesses of the corresponding self-assembled monolayers (SAMs) were evaluated by ellipsometry. The conformational characteristics of the SAMs were analyzed using polarization modulation infrared reflection adsorption spectroscopy (PM-IRRAS), with a focus on the C-H antisymmetric stretching vibrations of the alkyl spacers. To evaluate the packing densities of the monolayers, X-ray photoelectron spectroscopy (XPS) measurements were performed. Separately, contact angle measurements provided insights into the wettability of the surfaces. Remarkably, the contact angle data across a broad range of probe liquids for the γ-COC11SH and γ-COC12SH SAMs were consistently similar to each other and to the contact angle values of the PLGA surface, rather than to PGA. This finding suggests that the lactone-terminated SAMs investigated in this study effectively mimic nanoscale polyester surfaces, enabling the exploration of interfacial properties of polyesters in the absence of swelling and/or surface reconstruction phenomena. [ABSTRACT FROM AUTHOR]

The use of fiber-reinforced metal laminates (FML) is increasing due to their special mechanical properties. Their properties depend on the type and thickness of the metal and reinforcing fibers. In this study, the mechanical properties of FML sheets with a 2 mm thickness stainless steel 420 intermediate layer reinforced with six layers of Woven and Mat glass fibers were investigated. The fibers were impregnated with a polyester resin and produced as three layers on the front and back of the steel sheet with different fiber angles (0°, 15°, 30°, and 45°). Finally, samples with 8 mm thickness were cut by water jet. Mechanical properties including static tensile and bending tests were performed, and after that a low-cycle dynamic tensile and bending test was also performed according to the obtained maximum static tensile and bending force for each sample. The obtained results varied depending on the fibers' angle, but in all tests, the highest strength was obtained for samples with fibers arranged at 0°. A charpy impact and high speed pressure test were performed to determine toughness and confirm the strength and adhesion between the samples' layers. SEM imaging of the fracture surface showed good adhesion and bonding between layers. [ABSTRACT FROM AUTHOR]

Polyesters are an omnipresent material used for a variety of applications (e.g., bottles, packaging, textile, windshield), roughly comprising 8% of plastics produced worldwide. Enzymatic recycling is an emerging solution to deal with the increasingly diverse polyesters that are not suitable for mechanical recycling. However, enzyme activity and efficiency are still the limiting factors impeding enzymatic recycling for different plastic waste forms. The effects of thermal and structural properties (e.g., glass transition temperature, crystallinity, specific surface area), which are determined by chemical composition and preprocessing, directly influence enzyme recycling efficiency. This work investigates two extrusion methods (single screw and twin-screw extrusion) to pretreat a range of copolyesters (RPET, PETG, Ecozen, Tritan and PBT) and modify their properties (i.e., glass transition temperature (Tg), crystallinity (%), and molecular weight (Mn)). A PET-specific enzyme, leaf-branch compost cutinase (LCCICCG), produced from a fed-batch fermentation of Escherichia coli BL21(DE3), was used for the enzymatic depolymerization of different polyesters. Several copolyesters showed improved depolymerization after pretreatment, as measured by rate and amount of monomers produced. Those that did not depolymerize were found to have exceptionally high glass transition temperature or percent crystallinity, highlighting the importance of these physical parameters on conversion efficiency. [ABSTRACT FROM AUTHOR]

The wicking effect constitutes a pivotal determinant in facilitating the ingress and transference of liquid water within yarns and fabrics. Its significance looms prominently in the context of subsequent product processing, particularly concerning the immersion and interface bonding of textile matrix composites. The twist exerts profound influence over the fiber disposition and density within yarns, as well as the yarn and the wicking pathways for liquid water. We use a mathematical model grounded in the three-dimensional helical capillary permeation mechanism, inherently linked to the twist factor. This model operates under the assumption that the yarn's fibers exhibit uniform diameters and arrangements. Leveraging the macroscopic force equilibrium method, a function of liquid capillary rise with wicking time was deduced. and the dynamic progression of liquid water ascent within the yarn was simulated using the COMSOL platform. Subsequently, a series of wicking experiments were executed on polyester filament yarns, each characterized by varying twist levels. The results revealed that the experimental data coincided well with the theoretical prediction, thus affirming the model's accuracy. [ABSTRACT FROM AUTHOR]

The self-made COPET/CaCO3 masterbatch and PET masterbatch were used to modify the traditional PET fiber through melt spinning. The process parameters for preparing COPET/CaCO3/PET porous fiber by alkali and acid treatment were optimized using single factor control variable method, and the fiber properties were tested and characterized. The results show that when the NaOH mass fraction is 4% and the HCL mass fraction is 3%, the fibers have good apparent morphology and pore structure. Under the optimal treatment conditions, the fiber contains uniformly distributed pores, and the pore size is concentrated between 15 nm and 54 nm. The fracture strength, linear density, specific surface area, and melting temperature of the fibers are 1.29 cN/dtex, 4.84 dtex, and 5.527 3 m²/g, respectively, and 253.85 °C, respectively. [ABSTRACT FROM AUTHOR]

Rechargeable polymer‐based solid‐state batteries with metallic lithium anodes and LiNixMnyCo1−x−yO2 (NMC)‐based cathodes promise safer high‐energy‐density storage solutions than existing lithium‐ion batteries, but have shown challenging to realize. The failure mechanisms that have been suggested for these battery cells have mostly been related to the use of a metallic lithium anode and formation of dendrites during cycling. Here, we approach the issue of using solid polymer electrolytes (SPEs) vs. NMC cathodes by employing a range of materials based on poly(ϵ‐caprolactone‐co‐trimethylene carbonate) (PCL‐PTMC) with different salts under various cycling conditions. It is seen that although the ionic conductivity of the electrolyte can be improved by exchanging the lithium salt, it does not immediately correlate to better cycling performance. However, increasing the temperature during battery cycling to improve the ion transport kinetics lowers the polarization of the battery cell and full capacity can be achieved at an upper voltage cut‐off that is appropriate for the polymer electrolyte. For these electrolytes, the limit is demonstrated to be 4.4 V vs. Li+/Li, and cycling with NMC‐111 cathodes is thereby possible provided that the upper cut‐off is limited to below this limit. [ABSTRACT FROM AUTHOR]

Synthetic ropes are increasingly favored for use in offshore systems. Accurate predictions of the coupled hydrodynamic performance and structural response of offshore structures depends on a thorough understanding of the nonlinear characteristics of fiber materials. The objective of this study is to experimentally characterize the stiffness of a polyester mooring rope for a cylindrical floating production storage and offloading system. The quasi-static stiffness of the ropes and aged ropes after installation and the dynamic stiffness in various loading conditions were computed based on sub-rope tests following the guidelines from the American Bureau of Shipping. The quasi-static stiffness curves exhibited a linear decrease in values as the logarithm of the loading period (in minutes) increased. The dynamic stiffness was, in general, much higher than the quasi-static stiffness. The dynamic stiffness under various loading conditions revealed the complexities of the mechanical properties of polyester rope. Parameters such as the mean load, load amplitude, loading period, and loading cycles all had a notable impact. More tests are required to have a better understanding of their effects. [ABSTRACT FROM AUTHOR]

Pediatric forearm fractures, particularly involving the shaft or diaphysis, are common injuries typically resulting from accidental trauma during various activities. Traditional treatment involves closed reduction and casting; however, surgical intervention may be necessary in certain cases. The gold standard surgical approach utilizes elastic stable intramedullary nailing (ESIN), but a newer technique uses bioabsorbable intramedullary nails made of poly(lactic-co-glycolic acid) (PLGA). This study aims to compare the outcomes of these two surgical methods in pediatric diaphyseal forearm fractures. We retrospectively reviewed 86 patients who underwent operative treatment due to the diaphyseal fractures of the forearm in the Surgical Division, Department of Pediatrics, Medical School, University of Pécs, Pécs, Hungary between 2018 and September 2022. The mean age was 9.48 (ranging from 4 to 17). A total of 41 patients underwent surgery with PLGA implants (RESIN technique), while 45 patients were treated with titanium elastic nails (ESIN technique). Various factors including patient demographics, injury mechanisms, fracture characteristics, and complications were assessed. Both groups showed similar gender distribution, with a majority of fractures occurring in boys (the male–female ratio was 31:10 in the PLGA group, while in the titanium elastic nailing (TEN) group, this ratio was 29:16, with no statistical difference between the groups (p > 0.005). The average age of the patients treated with PLGA implants (8.439 years) was lower compared to those treated with titanium nails (10.422 years). A statistically significant difference was found regarding the average age of the two groups (p = 0.0085). Left-sided injuries were more prevalent in both groups (59% of the cases in the PLGA group and 69% in the TEN group, with no statistically significant difference, p = 0.716), and fractures typically involved both the radius and ulna. This represents 93% of the cases in the PLGA group and 80% in the TEN group. Regarding the involvement of bones, we also did not find a statistically significant difference (p = 0.123). The mechanisms of injury predominantly involved indirect force, such as falls (30 cases in the PLGA group and 27 cases in the TEN group), and no statistically significant difference was found (p = 0.139) regarding the mechanism of the injury. Complication rates were lower in the PLGA group (7%) compared to the titanium group (20%). The treatment of pediatric diaphyseal forearm fractures using PLGA implants appears to be a viable alternative to traditional titanium implants. Advantages include no need for secondary surgery and associated cost savings and reduced complication rate and stress associated with anesthesia and surgery. Prospective randomized trials are warranted to further validate these findings and explore long-term outcomes. [ABSTRACT FROM AUTHOR]

This review concerns the application of disperse dyes to poly(ethylene terephthalate) fibres using aqueous immersion dyeing processes and the roles of both elevated dyeing temperatures and carriers in the disperse dye/polyester fibre and disperse dye/carrier/polyester fibre dyeing systems, respectively. In this part of the paper, a mechanistic model of the disperse dye adsorption process is presented that is based on the role of dye solubility in disperse dye‐PET fibre substantivity. It is shown that the dye solubility model of disperse dye adsorption, which can be articulated using a simple mathematical approach, is able to account for the reasons why elevated dyeing temperatures are utilised in HT dyeing processes, and also why dyeing accelerants enable dyeing to be achieved using lower temperatures of ~100°C. [ABSTRACT FROM AUTHOR]

We report a new class of degradable fluorinated polymers through the copolymerization of tetrafluorophthalic anhydride and propylene oxide or trifluoropropylene oxide which show up to 20 times quicker degradation than the non-fluorinated equivalents and allow for fluoride recovery. [ABSTRACT FROM AUTHOR]

Kraft lignin (KL), an abundant and underutilized biobased aromatic resource, was valorized into polyester vitrimers showing enhanced recyclability. KL was first modified with ethylene carbonate, to expose only highly reactive primary aliphatic OH groups, allowing the direct synthesis of polyester networks by polycondensation with PEG-based dicarboxylic acid. In addition to avoiding the use of toxic acyl halides or coupling agents, this fast synthetic process yields networks in which the amount of free OH groups can be easily controlled by adjusting the stoichiometry between COOH and OH groups. The presence of free OH groups allows transesterification reactions resulting in a vitrimer behavior. Increasing the number of free OH groups promotes the stress relaxation process, but does not affect the activation energy, which is relatively low compared to typical transesterification vitrimers, owing to the specific network topology. High performance materials with improved mechanical and chemical recyclability were clearly demonstrated. Besides, the modified lignin can be recovered and isolated in high yields with only minor changes in its chemical structure, offering further upcycling opportunities. This makes lignin, the first aromatic and biobased resource, a raw material that can also be recycled, in line with the concept of a circular bioeconomy. [ABSTRACT FROM AUTHOR]

Aliphatic‐aromatic copolyesters offer a promising solution to mitigate plastic pollution, but high content of aliphatic units (>40 %) often suffer from diminished comprehensive performances. Poly(butylene oxalate‐co‐furandicarboxylate) (PBOF) copolyesters were synthesized by precisely controlling the oxalic acid content from 10 % to 60 %. Compared with commercial PBAT, the barrier properties of PBOF for H2O and O2 increased by more than 6 and 26 times, respectively. The introduction of the oxalic acid units allowed the water contact angle to be reduced from 82.5° to 62.9°. Superior hydrophilicity gave PBOF an excellent degradation performance within a 35‐day hydrolysis. Interestingly, PBO20F and PBO30F also displayed obvious decrease of molecular weight during hydrolysis, with elastic modulus >1 GPa and tensile strength between 35–54 MPa. PBOF achieved the highest hydrolysis rates among the reported PBF‐based copolyesters. The hydrolytic mechanism was further explored based on Fukui function analysis and density functional theory (DFT) calculation. Noncovalent analysis indicated that the water molecules formed hydrogen bonding interaction with adjacent ester groups and thus improved the reactivity of carbonyl carbon. PBOF not only meet the requirements of the high‐performance packaging market but can quickly degrade after the end of their usage cycles, providing a new choice for green and environmental protection. [ABSTRACT FROM AUTHOR]

The application of polymer composites is one of the most effective methods for preventing lubrication failure in deep‐sea engineering. In this study, fluorinated graphite (FGr) microsheets were incorporated into polytetrafluoroethylene (PTFE) microparticle‐filled poly(butylene terephthalate) (PBT) composites. The tribological performance in the simulated deep‐sea environment at elevated seawater pressure equivalent to 3000 m ocean depth was investigated. The results showed that FGr enhances the flexural and compressive strengths, thermal stability, and seawater resistance of the PTFE/PBT composite. The wear rate was decreased to 96% at the critical FGr content of 4% by improving the transfer onto the metallic counterfaces, preventing direct contact and shear between friction couples. Moreover, the seawater pressure impedes composite transfer, leading to a 29% increase in the wear rate. [ABSTRACT FROM AUTHOR]

The replacement of polymers derived from petrochemical resources has been a prominent area of focus in recent decades. Polymers used in engineering materials must exhibit mechanical strength and stiffness while maintaining performance through a broad temperature range. Most of the polyesters used as engineering materials are based on terephthalic acid (TPA) and its derivatives, which provide necessary rigidity to molecular chains due to an aromatic ring. Bio-based alternatives for TPA-based polyesters that are gaining popularity are the polyesters derived from 2,5-furandicarboxylic acid (FDCA). To broaden applicational possibilities, one effective way to achieve specific properties in targeted applications is to adjust the composition and structure of polymers using advanced polymer chemistry techniques. The incorporation of rigid diols such as isosorbide, 1,4-cyclohexanedimethanol (CHDM), and 2,2,4,4-tetramethyl-1,3-cyclobutanediol (CBDO) should result in a greater stiffness of the molecular chains. This review extensively explores the effect of incorporating rigid diols on material properties through a review of research articles as well as patents. Moreover, this review mainly focuses on the polyesters and copolyesters synthesized via two-step melt polycondensation and its alterations due to the industrial importance of this method. Innovative synthesis strategies and the resulting material properties are presented. [ABSTRACT FROM AUTHOR]

Nowadays, waste management is gaining popularity to reduce the environmental impact made by human beings. There is a dire need to decrease the pollution caused by plastic materials. A gradual rise in the demand for polyester bottles has generated a need to recycle these materials. In the present work, an aromatic amine (4,4′‐(1,4‐phenylenebis(1,3,4‐oxadiazole‐5,2‐diyl)) dianiline) was prepared from the polyester bottle waste. The successful synthesis and chemical structure of the amine was confirmed by various characterization techniques such as Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance spectroscopy (1H NMR), and 13C NMR. The amine was diazotized and coupled with H‐acid (4‐amino‐5‐hydroxy‐2,7‐naphthalene disulfonic acid)‐treated wool fabric to generate acid dye in situ on the fabric. The coloration (L*, a*, b*, and K/S) and fastness properties of dyed wool were evaluated, and the samples were further analyzed for antibacterial and UV‐protective properties. The dyed wool was also characterized by FTIR to confirm the presence of the aromatic group of the dye. The introduction of dye structure on the wool increased the thermal stability of the fabric, which was confirmed through thermogravimetric analysis analysis. Antibacterial activity (>70%) and excellent UV protection were retained by dyed wool after 20 washes. Furthermore, the dyed wool was found nontoxic under the cytotoxicity evaluation test. [ABSTRACT FROM AUTHOR]

Lignin is the largest source of renewable aromatics on earth. Despite numerous techniques for lignin depolymerization into mixtures of valuable monomers, methods for their upgrading into final products are scarce. The state of the art upgrading methods generally rely on catalytic funneling, requiring high temperatures, catalyst loadings and hydrogen pressure, and lead to the loss of functionality and bio-based carbon content. Here an alternative approach is presented, whereby the target monomers are selectively converted in unpurified mixtures into easily separable final products under mild conditions. We use reductive catalytic fractionation of wood to convert lignin into iso-eugenol and propenyl syringol enriched oil followed by an olefin metathesis to yield bisphenols and butene-2, thus, valorizing all bio-based carbons. To further demonstrate the synthetic utility of the obtained bisphenols we converted them into polyesters with a high glass transition temperature (Tg = 140.3 °C) and thermal stability (Td50% = 330 °C). Despite numerous techniques for lignin depolymerization into mixtures of valuable monomers, methods for their upgrading into final products are scarce. Here the authors present an alternative approach whereby the target monomers are selectively and directly converted in unpurified mixtures into easily separable bisphenols and butene-2 under mild conditions. [ABSTRACT FROM AUTHOR]

Constructing self‐repairing epoxy materials based on transesterification chemistry can be regarded as a potential path for practical industrial applications given on its simplicity and ease of processing. However, there is still a challenge to improve the slow bonding exchange process for desired healing performances. Herein, this work reports a simple and effective strategy to prepare high‐biomass‐content self‐repairing epoxy materials by introducing polyester oligomer (PEO) dicarboxylic acid as modifier into epoxidized soybean oil and itaconic acid compounds. The PEO is synthesized from glutaric anhydride and 1,4‐cyclohexanediol, as well possess a unique pentamer molecular structure. It not only endows the epoxy system with improved molecular mobility in virtue of its long‐chain structure, but also increases the number the essential ester groups of transesterification process, thus synergistically promoting bonding exchange rate for expected properties. As a result, the employment of PEO decreases the activation energy from 100 to 70 KJ/mol, as well as presents optimized self‐repairing efficiency in storage modulus and tensile strength tests compared to the control group. It may provide a new and practical way to fabricate high‐effective self‐repairing epoxy system for industrial applications. [ABSTRACT FROM AUTHOR]

The ternary copolymerization of a series of cyclic anhydrides with epoxides and carbon dioxide using dinuclear [OSSO]‐type chromium (III),1, and ‐iron(III), 2, complexes (0.1 mol %) in combination with (bis(triphenylphosphine)iminium chloride) (PPNCl, 0.5–1.0 mol with respect to catalyst) as co‐catalyst is reported in this study. The results have yielded copolymers with polyester and polycarbonate segments with high molecular weights and narrow dispersity. The catalytic systems 1–2/PPNCl were tested in the copolymerization of different epoxides, such as propylene oxide (PO), cyclohexene oxide (CHO), and vinylcyclohexene oxide (VCHO), with a variety of cyclic anhydrides, such as phthalic (PA), diglycolic (DGA) and succinic (SA), with CO2 pressure of 20 bar, temperature range of 45–80 °C in 24 h. Anhydride reaction, affording the polyester segments, exceeded the conversion of 99 % in all the explored cases. On the other hand, in the case of epoxide copolymerization with CO2, for the propylene oxide (PO) reaction, the selectivity towards polypropylene carbonate (PPC) without polyether linkage consistently was >99 %. For the terpolymerization of PO, CO2 and diglycolic anhydride (DGA), a notable epoxide conversion of 86 %, selectively to polycarbonate, with TOF value as high as 36 h−1, was achieved. [ABSTRACT FROM AUTHOR]

Sustainability has become increasingly important as environmental issues continue to rise. Biodegradable polymers offer a sustainable solution as they use biomass. In this study, biochar (BC) prepared by the pyrolysis of biomass was compounded with polybutylene succinate (PBS) to enhance its Young's modulus, and the residual BC was shown to amend the soil, following degradation. The incorporation of biochar into the PBS matrix is strategically achieved through a BC with treatment involving an aprotic polar solvent. This process not only reduces the size of the biochar particles but also ensures their uniform dispersion within the PBS matrix. As a result, a remarkable 2.5-fold increase in Young's modulus is observed, reaching an impressive 571.04 MPa, compared with the baseline Young's modulus of neat PBS, which stands at 220.92 MPa. Interestingly, the degradation rate of the resulting composites was comparable to that of neat PBS despite the decrease in the number of potential hydrolysis sites owing to the increased Young's modulus of the PBS/BC composite. These sustainable composite exhibited properties different from those of conventional PBS and is expected to be used in potentially novel applications toward environmental sustainability, such as in agricultural mulch films or electronic printing. [ABSTRACT FROM AUTHOR]

Poly(ethylene 2,5-furandicarboxylate) (PEF) is an important biobased polyester with better thermal, mechanical, and gas barrier properties than poly(ethylene terephthalate). In PEF synthesis, diethylene glycol furandicarboxylate (DF) is inevitably formed via etherification side reaction. Taking advantage of the side reaction, poly(ethylene-co-diethylene furandicarboxylate) (PEDF) poly(etherester)s were synthesized only from 2,5-furandicarboxylic acid (FDCA) and ethylene glycol (EG), using a cheap binary propanedisulfonic acid/dibutyltin oxide (PSA/DBTO) catalyst. The polymers were characterized by 1 H NMR, intrinsic viscosity, solubility, differential scanning calorimetry, thermogravimetric analysis, tensile, and gas barrier test. Due to strong acidity of PSA, not only major DF but also minor oligoethylene glycol furandicarboxylate ethercontaining units were formed. Their total content can be adjusted up to 78 mol % by simply increasing the dosage of PSA from 0 to 0.4 wt%. The effect of ether-containing units on the solubility, thermal transition, mechanical, and oxygen barrier properties of the poly(ether-ester)s were examined and compared with the poly(ether-ester)s synthesized via copolycondensation. [ABSTRACT FROM AUTHOR]