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In this study, a series of poly(butylene succinate)-based copolymers containing various quantities of dimethyl 2,6-naphthalene dicarboxylate (NDC) were synthesized via melt polymerization. The thermal stabilities of the copolymers were maintained, while a slight increment in the stability was observed as the NDC content increased. The results of differential scanning calorimetry and wide-angle X-ray diffraction demonstrated a reduction in the crystallizability of the copolymers with increasing NDC concentration. Unexpectedly, the tensile tests showed significant enhancement of the elongation rate from 122.5 to 2645.0% as the NDC content increased from 0 to 32 mol%. Samples with 28, 30, and 32 mol% NDC showed remarkable abilities with recovery rates above 90% after three test cycles. Moreover, apparent cut mark repairing behaviors were observed under 70 °C heating in samples containing 25, 28, and 30 mol% NDC. These results indicate the potential of the copolymers for self-healing and highly stretchable shape memory wound dressing material applications. [ABSTRACT FROM AUTHOR]

To improve the glass transition temperature and ultraviolet shielding properties of poly(butylene 2,5-thiophenedicarboxylate) (PBTF), a series of poly(butylene 2,5-thiophenedicarboxylate-co-butylene 4,4′-biphenyldicarboxylate) (PBTFBs) were synthesized from 2,5-thiophenedicarboxylic acid (TDCA), 1,4-butanediol (BDO), and dimethyl 4,4′-biphenyldicarboxylate (BDD). The composition and molecular weights of PBTFBs were investigated by 1H NMR,.13C NMR and GPC. The results showed that the glass transition temperature of PBTFBs gradually increased, and the thermogravimetric analysis results also showed that the thermal stability gradually increased with increasing the BDD content. Compared with PBTF, the polyester with 40% butylene 4,4′-biphenyldicarboxylate unit (PBTFB40) showed a higher Young's modulus (1166.8 MPa) and tensile strength (25.8 MPa). In addition, the ultraviolet (UV) shielding ability of PBTF was greatly enhanced, and the UV transmittance at 350 nm decreased from 19.66% (PBTF) to 6.22% (PBTFB30). The average transmittance at wavelengths of 320–400 nm decreased from 26.25 to 15.20%. The gas permeability coefficient of CO2 decreased from 0.3120 barrer to 0.0321 barrer. Because the biphenyl structure was successfully introduced into PBTF, the rigidity of the chain segment was improved, and excellent thermal stability, mechanical properties and UV shielding properties were obtained. PBTFB30 has potential application in outdoor products. [ABSTRACT FROM AUTHOR]

Copyright of China Plastics / Zhongguo Suliao is the property of Journal Office of CHINA PLASTICS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Poly(1,4-butylene succinate) (PBS) is a promising sustainable and biodegradable synthetic polyester. In this study, we synthesized PBS-based copolyesters by incorporating 5–20 mol% of –O2CC6H4CO2– and –OCH2CH2O– units through the polycondensation of succinic acid (SA) with 1,4-butanediol (BD) and bis(2-hydroxyethyl) terephthalate (BHET). Two different catalysts, H3PO4 and the conventional catalyst (nBuO)4Ti, were used comparatively in the synthesis process. The copolyesters produced using the former were treated with M(2-ethylhexanoate)2 (M = Mg, Zn, Mn) to connect the chains through ionic interactions between M2+ ions and either –CH2OP(O)(OH)O− or (–CH2O)2P(O)O− groups. By incorporating BHET units (i.e., –O2CC6H4CO2– and –OCH2CH2O–), the resulting copolyesters exhibited improved ductile properties with enhanced elongation at break, albeit with reduced tensile strength. The copolyesters prepared with H3PO4/M(2-ethylhexanoate)2 displayed a less random distribution of –O2CC6H4CO2– and –OCH2CH2O– units, leading to a faster crystallization rate, higher Tm value, and higher yield strength compared to those prepared with (nBuO)4Ti using the same amount of BHET. Furthermore, they displayed substantial shear-thinning behavior in their rheological properties due to the presence of long-chain branches of (–CH2O)3P=O units. Unfortunately, the copolyesters prepared with H3PO4/M(2-ethylhexanoate)2, and hence containing M2+, –CH2OP(O)(OH)O−, (–CH2O)2P(O)O− groups, did not exhibit enhanced biodegradability under ambient soil conditions. [ABSTRACT FROM AUTHOR]

The sorption of flavour compounds by PET and 15 copolyesters (PET copolymerized with isophthalic acid, adipic acid, sebacic acid, tetramethylene glycol, diethylene glycol, triethylene glycol and neopentyl glycol in the range of 5 to 18 mol%) was studied. Biaxially oriented films of each resin were immersed in aqueous solutions containing 37 types of flavour compounds for 4 weeks at 37°C. The amount of flavour compounds sorbed by the films was highly dependent on the copolymer composition. Among the tested films, the copolyester film containing 11 mol% sebacic acid exhibited the highest sorption of the 37 compounds, which was approximately 40 times that of PET. The copolyester film containing 11 mol% isophthalic acid exhibited the lowest sorption, approximately half that of PET. The relationship between sorption and the characteristic values of the polyester films was studied. Sorption was negatively correlated with the solubility parameter and density of the amorphous area and strongly negatively correlated with the glass transition temperature. It was concluded that the dynamic free volume involved in diffusion dominates the sorption of flavour compounds by copolyesters. The log P value and molecular size of the compounds had a strong effect on the sorption of individual flavour compounds by the films in aqueous solutions. [ABSTRACT FROM AUTHOR]

Copyright of China Plastics / Zhongguo Suliao is the property of Journal Office of CHINA PLASTICS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Dimethyl 3,3′-((ethane-1,2-diylbis(oxy))bis(4,1-phenylene))dipropionate (monomer M) was successfully synthesized from methyl 3-(4-hydroxyphenyl)propanoate and 1,2-dibromoethane by Williamson etherification, and a series of novel bio-sourced aliphatic–aromatic copolyesters were synthesized by melt copolymerization of M with resorcinol bis(2-hydroxyethyl) ether in combination with succinic acid, adipic acid, suberic acid, or dodecanedioic acid. The structure of these copolyesters was analyzed by Fourier transform infrared (FTIR) and proton nuclear magnetic resonance (1H NMR) spectroscopy. The weight-average molecular weight (Mw) of the samples varied from 39,300 to 46,200 g/mol, and the molar mass dispersity (Đ) from 2.16 to 2.31. The copolyesters had Tg values of 59–81 °C, and melting points of 161–172 °C. Tensile testing showed that the tensile strength of the copolyesters varied from 45 to 68 MPa, with elongation at break values of 235–343%. All the copolyesters exhibited good degradability, with weight losses in soil degradation reaching up to 4.3% after 30 days. It was also demonstrated that the four copolyesters synthesized in this study had low ecotoxicity through the earthworm ecotoxicity test. [ABSTRACT FROM AUTHOR]

Superparamagnetic iron oxide nanoparticles (SPIONs) have their use approved for the diagnosis/treatment of malignant tumors and can be metabolized by the organism. To prevent embolism caused by these nanoparticles, they need to be coated with biocompatible and non-cytotoxic materials. Here, we synthesized an unsaturated and biocompatible copolyester, poly (globalide-co-ε-caprolactone) (PGlCL), and modified it with the amino acid cysteine (Cys) via a thiol-ene reaction (PGlCLCys). The Cys-modified copolymer presented reduced crystallinity and increased hydrophilicity in comparison to PGlCL, thus being used for the coating of SPIONS (SPION@PGlCLCys). Additionally, cysteine pendant groups at the particle's surface allowed the direct conjugation of (bio)molecules that establish specific interactions with tumor cells (MDA-MB 231). The conjugation of either folic acid (FA) or the anti-cancer drug methotrexate (MTX) was carried out directly on the amine groups of cysteine molecules present in the SPION@PGlCLCys surface (SPION@PGlCLCys_FA and SPION@PGlCLCys_MTX) by carbodiimide-mediated coupling, leading to the formation of amide bonds, with conjugation efficiencies of 62% for FA and 60% for MTX. Then, the release of MTX from the nanoparticle surface was evaluated using a protease at 37 °C in phosphate buffer pH~5.3. It was found that 45% of MTX conjugated to the SPIONs were released after 72 h. Cell viability was measured by MTT assay, and after 72 h, 25% reduction in cell viability of tumor cells was observed. Thus, after a successful conjugation and subsequent triggered release of MTX, we understand that SPION@PGlCLCys has a strong potential to be treated as a model nanoplatform for the development of treatments and diagnosis techniques (or theranostic applications) that can be less aggressive to patients. [ABSTRACT FROM AUTHOR]

As one of the most commonly used thermoplastics, polyester has rarely been used as the raw materials of 3D printing. However, copolyester obtained by copolymerization modifying polyester, such as Poly Ethylene Terephthalate Glycol (PETG), has been proven to be suitable for the fused filament fabrication (FFF) technique in previous studies, but the mechanical performance of printed products is still poor. In this paper, 3D printed PETG is in‐situ reinforced by continuous carbon fiber (CCF), and the relationship between the process parameters and the mechanical performance of CCF/PETG is systematically investigated. The results show that the performance of 3D printed PETG is significantly enhanced by CCF in‐situ reinforcement due to the effectively impregnation of CCF. By optimizing process parameters, the tensile strength, flexural strength and flexural modulus of CCF/PETG are 597%, 293% and 650% of pure PETG, respectively, with a relatively low fiber mass fraction of 19.2 wt%. This paper demonstrates that CCF in‐situ reinforced 3D printed copolyester may be used in the manufacture of complex structural parts that require high mechanical performance in the engineering application. [ABSTRACT FROM AUTHOR]

Objects. Due to the polymer waste accumulation, the search for new directions for their utilization is urgent. Chemical recycling methods are of considerable interest, which allow one to obtain the original monomers or change the compositions of the copolymers. From the point of view of building a circular economy, a promising material is polyethylene terephthalate (PET), on the basis of which amorphous copolyesters can be obtained. The study aimed to analyze the simultaneous glycolysis and interchain exchange reactions of PET in the presence of the oligoethylene phthalate modifier with hydroxyl end groups and the study of isothermal crystallization of poly(ethylene phthalate-co-terephthalates) with different phthalate contents obtained in this way.Methods. Oligoethylene phthalate is synthesized by polycondensation. Poly(ethylene phthalateco-terephthalates) were obtained by the interaction of post-consumer PET with oligoethylene phthalate. The composition of the oligomer and copolymers was confirmed using Fourier-transform infrared spectroscopy, thermal characteristics and crystallization half-times were determined by differential scanning calorimetry.Results. In this work, the use of the post-consumer PET chemical recycling process, aimed at obtaining copolyesters under the influence of small modifier amounts was proposed. The process consisted in carrying out the combined interchain exchange and degradation with a complex oligoester different from PET. Poly(ethylene phthalate-co-terephthalate) copolymers were obtained via reaction of post-consumer poly(ethylene terephthalate) flakes and synthesized oligoethylene phthalate resin in the melt phase in the absence of catalyst. The effect of phthalate concentration in polymer on the isothermal crystallization of phthalate substituted poly(ethylene terephthalate) was estimated.Conclusions. The hypothesis about the possibility of using an oligoester modifier to obtain the PET-based copolymer at the high rate and without reducing the molecular weight to values characteristic of a monomer or oligomer has been confirmed. The process can be used to obtain random copolyesters based on post-consumer PET. The phthalate unit concentration increase is followed by decrease in the glass transition temperature, temperature and heat of fusion, and increase in crystallization half-times. Phthalate has a better ability to retard PET crystallization than 2-methyl-1,3-propanediol or furandicarboxylic acid, but is inferior to some of the other modifiers known.

• High molecular weight biodegradable PBIxSe copolyesters were successfully synthesized by one-pot polycondensation with 1,4-butanediol, isosorbide and sebacic acid. • The crystallinities of PBIxSe exhibited a decline as the content of IS units increased. • The introduction of IS unit accelerated the enzymatic hydrolysis rate of PBIxSe. • PBIxSe represented the biodegradability of compost, soil, seawater. The growing environmental concerns associated with the use of plastics highlight the need to mitigate carbon emissions and environmental pollution via biodegradable plastics development. Herein, biotechnologically accessible and renewable building blocks, namely 1,4-butanediol and sebacic acid, were copolymerized with carbohydrate-derived isosorbide to afford random poly(butylene-co-isosorbide sebacate) with variable isosorbide content. The thermal stabilities of these copolyesters and their biodegradabilities under (non)enzymatic hydrolysis, compost, soil, and marine conditions were examined as functions of isosorbide content. With the increasing isosorbide content, the glass transition temperature increased, whereas the crystallinity and melting temperature decreased. Isosorbide incorporation enhanced hydrolyzability under alkaline and enzymatic conditions, while demonstrating minimal impact under neutral and acidic conditions. The in-compost degradation rate increased with the increasing isosorbide content because of the concomitant decrease in melting temperature and crystallinity. In soil and marine environments, the copolyesters were degraded faster than poly(butylene sebacate). At 30 mol% isosorbide, the degradation extent reached 97.2 and 68.3 % after eight-week degradation in soil and 32-week degradation in a marine environment, respectively. This study is the first to report the biodegradability and degradation mechanisms of poly(butylene-co-isosorbide sebacate) and provides valuable insights into customizing the synthesis of biodegradable plastics to meet the degradation cycle requirements under various environmental conditions. [ABSTRACT FROM AUTHOR]

Plasticizer is an important assistant in the production process of polyvinyl chloride (PVC), which can effectively improve the plasticity of PVC. However, the durability and plasticizing effect of traditional phthalate plasticizers need to be further improved. In this paper, a variety of copolyesters are designed and synthesized from succinic acid, hexanediol and other four different diols. The plasticizing performance of the copolyester is characterized by FT-IR, H-NMR, XPS and DMA. It is found that the side chain groups in the structural units of the copolyester have a great influence on its plasticizing properties. The glass transition temperature of PVC plasticized by polybutylene succinate 3-chloro-1,2-propanediol ester (PSCH) is 8.1 ℃ lower than the temperature of PVC which is plasticized by DOP, and the elongation at break is increased by 104.7%. The obtained copolyester plasticizer with flexible long alkane chains and polar C–Cl groups shows improved solvent extraction resistance and better compatibility between plasticizer and PVC compared DOP. It is verified that the hydrogen bonding interaction between the C=O group of plasticizers and α-hydrogen of PVC exhibited in FT-IR, XPS and solubility parameters DS is the main reason for the effective plasticizing efficiency of PSCH on PVC. [ABSTRACT FROM AUTHOR]

This study evaluated the efficacy of different cleaning methods with respect to changes in the color and light transmittance of both rough and smooth thermoformed, copolyester retainer specimens, after staining in different solutions. Four hundred copolyester sheets (Essix ACE) specimens were fabricated over molds with different surface textures, smooth and rough. The specimens were stained in four different solutions (n = 100 per solution) over 28 days; then, each of the four groups of 100 stained specimens was sub-divided into five groups of 20 specimens and subjected to a different destaining solution. The specimens were sub-divided with half subjected to an additional ultrasonic cleaning procedure. Light transmittance and color changes were analyzed using a spectrometer/integrating sphere assembly and a spectrophotometer. Mean difference comparisons were performed using appropriate statistical tests at p = 0.05. All five destaining solutions proved to be effective at removing coffee and tea stains. The surface roughness of the retainer material plays a significant role in the ability of cleaning solutions to remove stains, demonstrating a greater effect on cleaning rough specimens with respect to improvements in light transmittance and greater changes in color. Additionally, an ultrasonic cleaning unit generally enhanced the ability of all five solutions to clean the tea-stained specimens. However, the enhancements were only significant for light transmittance. [ABSTRACT FROM AUTHOR]

Copyright of Advanced Textile Technology is the property of Zhejiang Sci-Tech University Magazines and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, a series of novel controllable shape-memory polymers composed of poly(ethylene terephthalate) (PET) and poly(ε-caprolactone) (PCL) were synthesized using the one-pot method and were spun using the melt spinning process. The chemical structure and composition, thermal properties, crystallization properties, mechanical properties, and shape-memory behavior of these copolymers were characterized. The results revealed that the incorporation of a flexible PCL segment achieved random copolymers. The aliphatic PCL segment decreased the melting point, crystallinity, and glass transition temperature. The thermal stability of the synthesized PET-co-PCLs was higher than that of the blended polymers, and the decomposition temperature of PET-co-PCL-30 % reached 377.2 °C. The shape recovery ratio of PET-co-PCL-30 % was between 38.32 % and 82.69 % and was temperature dependent. The as-spun PET and PET-co-PCL fibers were melt spun at a winding rate of 1,000 m/min. The strength values of the fibers ranged from 2.16 to 1.2 gf/den depending on the increase in PCL content. Because of the biocompatibility of both PET and PCL and the shape-memory features of these copolyesters, PET-co-PCL fibers can be applied in intelligent textiles. [ABSTRACT FROM AUTHOR]

Copyright of China Synthetic Fiber Industry is the property of Sinopec Baling Petrochemical Company and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The closed-loop recycling concept of the polymer wastes into building-block chemicals is attractive, but the closed-loop recycling of copolymers enabled by energy-efficient chemical recycling and cost-effective separations is still facing great challenges. Herein, for the first time, a one-pot sequential copolymerization of γ-butyrolactone (γ-BL) and p-dioxanone (PDO) using an economical ureas/alkoxides catalytic system is conducted to synthesize biodegradable and chemically recyclable poly-(γ-butyrolactone)-block-poly(p-dioxanone) (PγBL-b-PPDO) diblock copolymers with well-defined and controlled structures. The composition-dependent properties of PγBL-b-PPDO copolymers, including thermal properties and crystallization behavior, are investigated. The results show that the thermal stability and crystalline ability of PγBL are enhanced observably by introducing the PPDO block. Significantly, the PγBL-b-PPDO copolymers can be depolymerized efficiently into the corresponding co-monomers with a yield of over 95% by simply low-temperature pyrolysis under vacuum. Moreover, γ-BL and PDO monomers are selectively separated with an isolated purity of about 99% based on the difference in their physicochemical properties. Subsequently, their repolymerization is realized to obtain the copolymers with nearly identical structures and thermostability, demonstrating the closed-loop recycling of copolymers, i.e., polymerization-depolymerization-repolymerization. This research provides important guidance for the design of novel sustainable polymers towards more efficient chemical recycling, separation and regeneration. [ABSTRACT FROM AUTHOR]

Copyright of Plastics Science & Technology / Suliao Ke-Ji is the property of Plastics Science & Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Donghua University (Natural Science Edition) is the property of Journal of Donghua University (Natural Science) Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This work describes the synthesis and physicochemical and microstructural characterization of poly(sorbitol adipate co-citrate) with the aim of obtaining a sustainable biopolymer derived from renewable and non-toxic sources intended for applications such as biomaterial. Polymerizations at three different ratios of sorbitol and adipic and citric acids (A, B and C) were studied. The materials were characterized by X-ray diffraction (XRD), infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) techniques. Such analyses showed that only in state C was an amorphous copolyester obtained, with different particle sizes and visibly hard and with a translucent yellowish color. [ABSTRACT FROM AUTHOR]

Superparamagnetic iron oxide nanoparticles (SPIONs) have their use approved for the diagnosis/treatment of malignant tumors and can be metabolized by the organism. To prevent embolism caused by these nanoparticles, they need to be coated with biocompatible and non-cytotoxic materials. Here, we synthesized an unsaturated and biocompatible copolyester, poly (globalide-co-ε-caprolactone) (PGlCL), and modified it with the amino acid cysteine (Cys) via a thiol-ene reaction (PGlCLCys). The Cys-modified copolymer presented reduced crystallinity and increased hydrophilicity in comparison to PGlCL, thus being used for the coating of SPIONS (SPION@PGlCLCys). Additionally, cysteine pendant groups at the particle’s surface allowed the direct conjugation of (bio)molecules that establish specific interactions with tumor cells (MDA-MB 231). The conjugation of either folic acid (FA) or the anti-cancer drug methotrexate (MTX) was carried out directly on the amine groups of cysteine molecules present in the SPION@PGlCLCys surface (SPION@PGlCLCys_FA and SPION@PGlCLCys_MTX) by carbodiimide-mediated coupling, leading to the formation of amide bonds, with conjugation efficiencies of 62% for FA and 60% for MTX. Then, the release of MTX from the nanoparticle surface was evaluated using a protease at 37 °C in phosphate buffer pH~5.3. It was found that 45% of MTX conjugated to the SPIONs were released after 72 h. Cell viability was measured by MTT assay, and after 72 h, 25% reduction in cell viability of tumor cells was observed. Thus, after a successful conjugation and subsequent triggered release of MTX, we understand that SPION@PGlCLCys has a strong potential to be treated as a model nanoplatform for the development of treatments and diagnosis techniques (or theranostic applications) that can be less aggressive to patients.

In this investigation, a new wholly aromatic random copolyester containing 4,4'-dihydroxybiphenyl, 3,5-dihydroxytoluene and Isophthaloyl chloride was synthesized using the solution polycondensation methodology in the mole ratio 2:1:3 and its solubility along with inherent viscosity were determined. The chemical structure of the copolyester was established by traditional spectroscopic techniques. The physical parameters of the polyester were studied employing WAXD studies and the thermal stability along with phase transitions were investigated employing TGA and DSC data. The morphological features in the polyester were probed using Scanning Electron Microscopy. The anticancer activity of copolyester was verified using HeLa (Cervical carcinoma) cell line employing MTT assay. [ABSTRACT FROM AUTHOR]

Polyhydroxybutyrate (PHB) is a biodegradable polymer, and preparation of a blend with another biodegradable polymer, polybutylene adipate terephthalate or Ecoflex® (ECO) is described. Some works in the previous literature show the possibility of preparing blends involving both. The techniques normally used previously described normally an extrusion process or even mixers that require high investment such as HAAKE Rheomix, for example. The main contribution is use of an original and simple technique, especially with low cost in relation to the earlier works described elsewhere. Obtaining solutions of both polymers and studies of miscible mixtures is the basis of the blending preparation process. The mass percentage ratios used to prepare the blends were 5, 10 and 20% ECO in PHB. Fourier transform infrared spectroscopy, scanning electron microscopy (SEM) and dynamic-mechanical thermal analysis (DMA) were used for characterization of blends. It was observed an increase in the flexibility of blends when compared to PHB as pointed out in the recent literature. By using SEM, it was concluded that there is interaction between the phases present in the blend and this interaction benefits miscibility. The results obtained by the DMA analyses in flexion modulus and by the differential scanning calorimetry (DSC) curves showed miscibility is dependent on ECO concentration as expected. [ABSTRACT FROM AUTHOR]

Polyester is widely used in household products because of its good mechanical properties and wears resistance, but polyester is easy to ignite and inclined to produce droplet, so its application range is limited. The cross‐linkable magnesium hydroxide nanoparticles were incorporated into flame‐retardant polyester, which enables the phosphorus‐containing copolyester with thermal cross‐linking and anti‐meltdrop properties. The nanoparticles were achieved by in situ polymerization and acted as a nucleating agent for improving the crystalline properties of the copolyester. Furthermore, the nanoparticles also enhanced anti‐meltdrop properties and reduced the heat and gas release during the combustion process of the copolyester. The maximum heat release rate and total smoke release reduced by 39.8% and 74.4% compared with pure polyester. Specifically, the combustion products of the nanoparticles and phosphorus flame retardant could act a barrier role by covering the carbon layer to isolate air and heat, thereby resulting in excellent anti‐meltdrop properties. The simple modification method reported here realizes the collaborative modification of flame retardant and anti‐meltdrop properties of phosphorous flame‐retardant copolyesters by thermal cross‐linking. [ABSTRACT FROM AUTHOR]

The ever-increasing use of plastics, their fossil origin, and especially their persistence in nature have started a wave of new innovations in materials that are renewable, offer the functionalities of plastics, and are biodegradable. One such class of biopolymers, polyhydroxyalkanoates (PHAs), are biosynthesized by numerous microorganisms through the conversion of carbon-rich renewable resources. PHA homo- and heteropolyesters are intracellular products of secondary microbial metabolism. When isolated from microbial biomass, PHA biopolymers mimic the functionalities of many of the top-selling plastics of petrochemical origin, but biodegrade in soil, freshwater, and marine environments, and are both industrial- and home-compostable. Only a handful of PHA biopolymers have been studied in-depth, and five of these reliably match the desired material properties of established fossil plastics. Realizing the positive attributes of PHA biopolymers, several established chemical companies and numerous start-ups, brand owners, and converters have begun to produce and use PHA in a variety of industrial and consumer applications, in what can be described as the emergence of the “PHA industry”. While this positive industrial and commercial relevance of PHA can hardly be described as the first wave in its commercial development, it is nonetheless a very serious one with over 25 companies and start-ups and 30+ brand owners announcing partnerships in PHA production and use. The combined product portfolio of the producing companies is restricted to five types of PHA, namely poly(3-hydroxybutyrate), poly(4-hydroxybutyrate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate), poly(3-hydroxybutyrate-co-4-hydroxybutyrate), and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate), even though PHAs as a class of polymers offer the potential to generate almost limitless combinations of polymers beneficial to humankind. To date, by varying the co-monomer type and content in these PHA biopolymers, their properties emulate those of the seven top-selling fossil plastics, representing 230 million t of annual plastics production. Capacity expansions of 1.5 million t over the next 5 years have been announced. Policymakers worldwide have taken notice and are encouraging industry to adopt biodegradable and compostable material solutions. This wave of commercialization of PHAs in single-use and in durable applications holds the potential to make the decisive quantum leap in reducing plastic pollution, the depletion of fossil resources, and the emission of greenhouse gases and thus fighting climate change. This review presents setbacks and success stories of the past 40 years and the current commercialization wave of PHA biopolymers, their properties, and their fields of application.

Poly(ethylene-co-isosorbide terephthalate) (PEIT) copolyesters could be used in various applications depending on their ability to crystallize. Moreover, the possibility to carry out solid-state post-condensation (SSP) is conditioned by its ability to sufficiently crystallize. The present study, thus, gives a systematic investigation of isothermal crystallization of these statistical copolyesters with isosorbide contents ranging from 4.8 to 20.8 mol.%. For each copolyester composition, the lowest isothermal half crystallization times and the highest Avrami constant (K) were obtained around 170 °C. Over the range of composition that was studied, both melting points and melting enthalpies decreased with increasing amounts of isosorbide (from 250 to 207 °C and from 55 to 28 J/g, respectively). On the contrary, half crystallization time displayed an exponential increase when increasing isosorbide contents in the studied range. Finally, structural and thermal analysis of PIT homopolyester are reported for the first time, showing that only ET moieties crystallized when PEIT was subjected to isothermal crystallization at 170 °C. [ABSTRACT FROM AUTHOR]

The main purpose of this study is to highlight the thermal and mechanical characterization of printed copolyester-based polymer. The variety of benefits of this material, such as its food contact compliance and important mechanical properties, have proved to be effective in huge field of applications, including medical sector and packaging uses. However, it has not received much attention for 3D printing processes. As the printing temperature is a key parameter of fused deposition modeling (FDM) process, the present study is started by analyzing its effect on the mechanical properties of printed copolyester under tensile loading. Indeed, the determination of temperature optimal values to print this material with FDM process is done based on tensile properties, including tensile strength, Young's modulus, ultimate tensile and yield strength, ductility and fracture toughness. The fracture properties of printed copolyester are also discussed using “scanning electron microscopy” (SEM). The results indicate a strong effect of the extrusion temperature on tensile properties. In addition, the analysis of copolyester sample microstructure reveals several damage mechanisms within the printed parts that reflect different types of wires fracture form subjected to the same tensile loading.

• Addition of phosphonium Ionic Liquid interestingly modifies mechanical properties of PBAT. • Depending on the counter anion, the ionic liquid is miscible or not with PBAT. • AFM nanomechanical mappings highlights the complex structurating mechanism. • Dielectric spectroscopy helps to identify rigid and mobile amorphous phases. The influence of the addition in small amounts (2 wt%) of two phosphonium–based ionic liquids (ILs) on the nanostructuration and mechanical properties of a poly(butylene-adipate- co -terephtalate) (PBAT) matrix was investigated using complementary approaches. Dielectric spectroscopy and nanomechanical characterizations using atomic force microscopy (PeakForce QNM mode, Bruker) were used along X-ray diffraction, differential scanning calorimetry and dynamic mechanical analysis to explain the mechanical (tensile) properties of each system. The semicrystalline matrix was found to have a spherulitic structure, with crystalline lamellae composed of butylene terephtalate units. In one case, the addition of an immiscible phosphonium-phosphinate ionic liquid (il-TMP) to the matrix, inducing a 33% increase of the strain at break, was found via AFM to induce a nodular microstructure with dissipative effects and smooth nodule-matrix interphases. In the other case, a phosphonium-chloride ionic liquid (il-Cl), being miscible in the amorphous phases, increases the chain mobility of the mobile amorphous fraction (MAF) consisting of free polymer chains, while it hinders the relaxation, thus chain movements, of the confined rigid amorphous fraction (RAF). This double effect induced a moderate macroscopic Young's modulus drop (less than −20%) with a +60% increase of the strain at break, and no significant influence on thermal properties. AFM in situ mechanical measurements, along with dielectric spectroscopy, allowed to propose complete mechanisms for the ILs-matrix interactions, highlighting the potential of such additives for the tuning of the properties of polymers. [ABSTRACT FROM AUTHOR]

A series of three random copolyesters comprising biscoumarin and chalcone units as prime monomers, spaced with aliphatic alkyl chains of varying methylene units and 4,4′-oxydibenzoate, was synthesized and characterised by FTIR, NMR, TGA, DSC and XRD. The antimicrobial activity of the copolyesters was studied using Agar disc diffusion and broth dilution assay. The inhibitory effects of copolyesters were higher for Gram positive than Gram negative bacteria. All the copolyesters exhibited appreciable antimicrobial activity. In particular, copolyester 4c, poly(biscoumarin-4,4′-oxydibenzoate-3-methoxychalcone) exhibited highest inhibition zone range of 19±0.39 mm for Bacillus subtilis, 20±0.51mm for Staphylococcus aureus and 20±0.22 mm for Staphylococcus epidermidis. Bacillus subtilis was more sensitive towards copolyester 4c exhibiting a minimum inhibitory concentration of 39.05 μg/mL. Chalcone coupled biscoumarin copolyester presented good antimicrobial activities comparable with those of standard antimicrobial agents, Chloramphenicol and Amphotericin-B. Thus the incorporation of biscoumarin and chalcone units in the polymer chain exhibit very good antimicrobial activity against gram positive bacterial and fungal strains. [ABSTRACT FROM AUTHOR]

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This article describes 1,4-dithiane-2,5-diol as a monomer to synthesize aliphatic random copolyester which PDDD was synthesized by direct melt polycondensation method and characterized by FT-IR and 1H-NMR. The physical properties of PDDD were characterized by X-ray diffraction, differential scanning calorimetry, as well as viscosity and solubility measurements. The anticancer, antioxidant, and antimicrobial activity of PDDD were evaluated to investigate its potential biomedical applications. Good results were obtained. It is evident that the copolyester exhibits favorable and tunable physical, thermal and biological properties and so is a suitable candidate for biomedical applications. [ABSTRACT FROM AUTHOR]

In this study, the preparation and properties of poly(ethylene terephthalate-co-2-methyl-1,3-propanediol) copolyester (PEMT) were reported. The PEMT crystallization properties, optical properties, thermal properties, rheological properties, and other properties were characterized by nuclear magnetic resonance (1H NMR), differential scanning calorimetry, thermo gravimetric analysis, ultraviolet visible near-infrared (UV-VIS-NIR) spectroscopy, polarizing microscope crystal culture, X-ray diffraction (XRD), and rheometer. It was proved that the crystallization abilities and crystallization rate of PEMT copolyesters were significantly affected by the content of 2-methyl-1,3-propanediol (MPO) units; the copolyester becomes amorphous when the content of MPO units exceeded 20 mol%. According to the XRD data, the diffraction peaks of PEMT remained unchanged compared with those of poly(ethylene terephthalate). The transmittance of copolyesters displayed a tendency of increasing at first and then declining with the increase in MPO. In addition to the crystallization properties, the transmittance of copolyesters was also affected by the extent of yellowing. When the MPO addition was less than 20 mol%, PEMT can maintain good thermal decomposition performance and processability. [ABSTRACT FROM AUTHOR]

Poly(ethylene-co-isosorbide terephthalate) (PEIT) copolyesters could be used in various applications depending on their ability to crystallize. Moreover, the possibility to carry out solid-state post-condensation (SSP) is conditioned by its ability to sufficiently crystallize. The present study, thus, gives a systematic investigation of isothermal crystallization of these statistical copolyesters with isosorbide contents ranging from 4.8 to 20.8 mol.%. For each copolyester composition, the lowest isothermal half crystallization times and the highest Avrami constant (K) were obtained around 170 °C. Over the range of composition that was studied, both melting points and melting enthalpies decreased with increasing amounts of isosorbide (from 250 to 207 °C and from 55 to 28 J/g, respectively). On the contrary, half crystallization time displayed an exponential increase when increasing isosorbide contents in the studied range. Finally, structural and thermal analysis of PIT homopolyester are reported for the first time, showing that only ET moieties crystallized when PEIT was subjected to isothermal crystallization at 170 °C.

Together with other so-called “bio-plastics”, Polyhydroxyalkanoates (PHAs) are expected to soon replace established polymers on the plastic market. As a prerequisite, optimized process design is needed to make PHAs attractive in terms of costs and quality. Nowadays, large-scale PHA production relies on discontinuous fed-batch cultivation in huge bioreactors. Such processes presuppose numerous shortcomings such as nonproductive time for reactor revamping, irregular product quality, limited possibility for supply of certain carbon substrates, and, most of all, insufficient productivity. Therefore, single- and multistage continuous PHA biosynthesis is increasingly investigated for production of different types of microbial PHAs; this goes for rather crystalline, thermoplastic PHA homopolyesters as well as for highly flexible PHA copolyesters, and even blocky-structured PHAs consisting of alternating soft and hard segments. Apart from enhanced productivity and constant product quality, chemostat processes can be used to elucidate kinetics of cell growth and PHA formation under constant process conditions. Furthermore, continuous enrichment processes constitute a tool to isolate novel powerful PHA-producing microbial strains adapted to special environmental conditions. The article discusses challenges, potential and case studies for continuous PHA production, and shows up new strategies to further enhance such processes economically by developing unsterile open continuous processes combined with the application of inexpensive carbon feedstocks.

Graphical abstract Highlights • Bio-based poly(ethylene 2,5-furandicarboxylate- co -ε-caprolactone)s (PEFCLs) were prepared via copolymerization. • PEFCL40 had a Young's modulus 1182 ± 80 MPa, a tensile strength 51 ± 3 MPa and an elongation as high as 981 ± 117%. • The modified materials maintained good thermal stability. Abstract A new bio-based copolyesters, poly(ethylene 2,5-furandicarboxylate- co -ε-caprolactone) (PEFCL), were synthesized from 2,5-furandicarboxylic acid, ethylene glycol and ε-caprolactone. The obtained copolyesters were characterized in terms of chemical structures, thermal and mechanical properties. The characterization results of 1H NMR and 13C NMR had confirmed the insertion of lactones units in PEF chains, all PEFCL copolyesters showed random microstructures. These bio-based copolymers were amorphous and had one glass transition temperature decreased as increasing the CL content. The thermal stability of PEFCL is slightly lower than PEF. Tensile testing revealed that introduction of ε-caprolactone into PEF chains impart PEFCL with excellent mechanical performance, typically, PEFCL40 had a Young's modulus 1182 ± 80 MPa, a tensile strength 51 ± 3 MPa and an elongation as high as 981 ± 117%. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • High temperature to lead copolyester printability with fused deposition modelling. • Low stiffness but acceptable tensile strength of 3D printed copolyester. • Failure patterns of printed copolyester reveal combination of three damage mechanisms. Abstract The aim of this study is to investigate the printability conditions of a copolyester based polymer that has not received yet much attention. This material presents several advantages over PLA and ABS including its food contact compliance and BPA (Bisphenol A) free formulation. The determination of optimal conditions to print copolyester with FDM process was done by quantifying the influence of printing temperature on thermal behavior and tensile properties including Young's modulus, yield stress, tensile strength, ultimate properties, and fracture toughness. Analysis of damage mechanisms through the observation of fracture surfaces of printed copolyester were also performed using SEM. The results indicate a strong relationship between thermal cycling, tensile properties and printing temperature. It is also shownthat the mechanical behavior of printed copolyester is significantly affected by the filament arrangement within the meso-structure. Particular fracture patterns are revealed, which suggest the simultaneous action of three main damage mechanisms triggered by the inhomogeneous change in the filament morphology at the rupture point. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Waste truck tire was used in preparation of thermoplastic vulcanizates (TPVs). • Increases of CB loadings resulted in increase of tensile strength and hardness. • The CB particles were proved to mainly localize in the DR phase. • Micron size rubber domains were a result of high shear and enhanced viscosities. • Rate of stress relaxations was found to be increased with increasing CB loadings. Abstract Devulcanized rubber (DR) was prepared from waste truck tire rubber via thermo-chemical devulcanization process. Thermoplastic vulcanizates (TPVs) based on blending of DR and copolyester (DR/COPE) were prepared. Effects of carbon black loading on microstructure, mechanical properties and elastomeric behaviors of dynamically cured DR/COPE blends were investigated. It was found that increasing of the carbon black loadings leads to transformation from co-continuous phase structure to dispersion of smaller vulcanized rubber domains in the COPE matrix. Furthermore, the carbon black was well dispersed in the DR/COPE matrix up to 10 wt% and then the aggregates slightly occurred with increasing of carbon black loadings. In addition, dynamic experiments proved that a progressive non-linear behavior was more pronounced with increasing of carbon black loadings. Also, tan δ max of the DR phase decreases with increasing carbon black concentration indicating mainly localization of filler in rubber phase. Moreover, it was found that increases of CB loadings resulted in increase of tensile strength and hardness while the elongation at break was slightly decreased. Additionally, the rate of stress relaxations was found to be increased with increasing CB loadings. [ABSTRACT FROM AUTHOR]

ABSTRACT: A series of tetrapolyesters were obtained by polymerizing phloretic acid, hydroquinone, p‐hydroxybenzoic acid, or its derivatives, that is, vanillic acid or syringic acid, and dodecanedioic acid. Each monomer was polymerized in its acetylated form, except for the diacid to undergo polymerization by acidolysis. Initial polymerizations had shown that the use of phloretic acid resulted in better polymer properties than with p‐coumaric acid. The predominantly renewable polymers were obtained by melt polymerization using a two‐stage condensation process whereby antimony(III) oxide was applied as catalyst. Monomer conversions were typically close to 90%. 1H and 13C NMR, DSC, TGA, solution viscometry, and GPC were applied, as well as polarized microscopy to determine polymer microstructure and composition, transition temperatures, decomposition temperatures, intrinsic viscosities, and other molecular weight properties, and when applicable the liquid crystalline behavior of the polymers. All peaks, including end group peaks in the 13C NMR spectra were assigned, the monomer sequence distribution was verified to be random, and a complete dyad analysis involving nine dyads and eight peaks was performed. By using p‐hydroxybenzoic acid and its derivatives without any, one or two methoxy groups and varying the copolymer compositions, melting temperatures could be tuned between 106 and 181 °C. The tetrapolyesters, which included residues of p‐hydroxybenzoic acid, formed nematic liquid crystals. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 1498–1507 [ABSTRACT FROM AUTHOR]