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L-Phenylalanine-ε-caprolactone-based polyesteramides (PCPs) were synthesized via melt polycondensation across a diverse range of molar compositions. The copolymer structure was extensively characterized using nuclear magnetic resonance (NMR) and matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS). NMR analysis confirmed the intercalation of the L-Phenylalanine comonomer units within the polyester backbone. MALDI MS characterization further demonstrated the formation of linear PCP chains with carboxyl end groups. A detailed structural analysis through MALDI MS/MS fragmentation indicated that ester bond scission was the predominant fragmentation mechanism, depicting the polyesteramide sequence in the copolymers. The resulting copolymers were primarily amorphous, except for those with molar compositions of 90/10 and 80/20, which exhibited semi-crystalline structures. Additionally, these PCPs showed an increase in glass transition temperatures with higher amino acid contents and demonstrated good thermal stabilities, as evidenced by a 10% mass loss at elevated temperatures. [ABSTRACT FROM AUTHOR]

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Organic solvent nanofiltration (OSN) is an emerging energy-efficient separations technology, which urgently requires easily processable OSN membranes with high selectivity and broad-spectrum organic solvent applicability to facilitate enhanced industrial applications. Herein, we describe the preparation of microporous polyesteramide (PEA) membranes through interfacial polymerization (IP) between amino-diphenol monomers and trimesoyl chloride (TMC) on a poly(ether ether ketone) (PEEK) support. The crosslinked network structures and large twisted monomers enhance the microporosity of PEA membranes, leading to a significant improvement in solvent permeance while maintaining high selectivity. The optimized PEA membrane demonstrates exceptional permeance for acetone (21.0 ​L ​m−2 ​h−1 bar−1) and methanol (14.3 ​L ​m−2 ​h−1·bar−1), with a molecular weight cut-off of 296 ​g ​mol−1. Additionally, the PEA/APH-diphenol membrane exhibits ultrafast permeance for the nonpolar solvent toluene (8.3 ​L ​m−2 ​h−1·bar−1), owing to the introduction of a large number of ester groups. Overall, PEA membranes prepared through the molecular-level structure design of IP monomers possess enormous industrial application potential owing to their high performance and broad-spectrum applications.

Within the context of paving the way for a sustainable bioeconomy, there is a strong emphasis on utilizing bio-based raw materials as substitutes for fossil fuels in the production of polymers. When designing the synthesis of novel polymeric materials from bio-based building blocks, a promising green approach consists in utilizing enzymes as biocatalysts. This aspect is particularly important when aiming to obtain products from the class of polyesters and polyesteramides with biocompatible and biodegradable properties, as enzymes facilitate the synthesis of polymers that align closely with biological systems. Lipases have been proven to be very effective in the synthesis of polymers, particularly in the ring-opening polymerization of ε- caprolactone. Considering the possibility of performing the copolymerization of ε- caprolactone for obtaining random and block structures, this is the first comparative study of the enzymatic polymer synthesis utilizing an innovative approach of combining ring-opening polymerization with polycondensation. Terpolymers derived from ε- caprolactone and dimethyl itaconate or dimethyl adipate with either 1,8-octanediol or 1,8-octanediamine were obtained at 85 °C in a solventless systems, yielding products with a copolymer content of >85 % and weight-average molecular weight (M w) up to 40,000 Da. The thermal properties and biodegradation behavior of the synthetized terpolymers were assessed. • Enzymatic synthesis of terpolymers from ε-CL, DMI/DMA, and ODO/ODA was achieved. • Equimolar ratio of the monomers led to >92 % conversion and low dispersity. • Among the tested initiators water (10 %) was the most effective initiator in ε-CL ROP. • Combining different monomers four new polyesters/polyesteramides were obtained. • Biodegradability of all samples tested exceeded 40 % after 30-day evaluation. [ABSTRACT FROM AUTHOR]

This article describes the synthesis of polyesteramide (PEA) resin from Leucaena leucocephala oil (LLO) obtained from seeds of L. leucocephala tree, locally grown in King Saud University Campus. LLO was transformed into amide diol by based catalyzed amidation reaction, followed by esterification reaction with malic acid (MA), that resulted in LLO-based PEA (LPEA). The synthesis was performed without using any solvent or catalyst. Fourier-transformation infrared spectroscopy and nuclear magnetic resonance confirmed the formation of LPEA by the introduction of amide and ester moieties. LPEA was further reinforced with nano graphene oxide (GO) and fabricated into nanocomposite corrosion protective coatings (LPEA/GO). LPEA/GO coatings obtained were tough, flexibility retentive and showed good corrosion resistance performance toward 3.5 w/w% NaCl medium. Thermogravimetric analysis confirmed good thermal stability of coatings with safe usage up to 200°C.

Polyesteramide polyol was synthesized by employing aminolysis with a base catalyst with custard apple seed oil as source material. It was afterward esterified with phthalic anhydride to form polyesteramide polyol. Polyurethane coatings are produced by combining polyesteramide polyols, which are synthesized, with hexamethylene diisocyanate trimer (HDI). The co-precipitation technique was used to synthesize a nickel-aluminum layered double hydroxide (Ni-Al LDH). Subsequently, the synthesized Ni-Al LDH was further modified by incorporating the corrosion inhibitor 2-mercaptobenzothiazole (MBT) into its interlayer space by the in-situ method. The synthesized Ni-Al LDH and Ni-Al-MBT LDH are then incorporated into the polyesteramide polyol to enhance the anti-corrosive properties of the polyurethane coatings. The synthesized diethanolamide, polyesteramide polyol, and LDH have been characterized using FTIR whereas SEM and XRD are specific to LDH analysis. EIS, DSC, TGA, salt spray, contact angle, and mechanical testing such as thickness, adhesion flexibility, scratch hardness, impact resistance, and pencil hardness are focused on coating evaluation. The incorporation of LDH led to a substantial enhancement in the coating's corrosion resistance, as evidenced by a decrease in corrosion. Incorporating LDH and MBT-LDH improved the scratch resistance of the coating by 1.5 kg compared to plain PU coating, whereas hardness properties also improved slightly. In anticorrosive analysis, it is observed that LDH and MBT-LDH show better anticorrosive performance as compared to plain PU coating. [Display omitted] • Utilization of waste seed-based oil for the development of coating and its performance improvement with layered materials. • Synthesis and characterization of polyesteramide polyol from custard apple seed oil. • Incorporation of nickel-aluminum layered double hydroxide (Ni-Al LDH) and LDH-MBT into the polyesteramide polyol. • Characterization- FTIR, SEM, XRD, EIS, DSC, TGA, salt spray, and mechanical testing to evaluate the LDH-modified coatings. • Significant improvement in corrosion resistance observed in the LDH-modified polyurethane coatings. [ABSTRACT FROM AUTHOR]

• The properties of carboxylated chitosan/trimesoyl chloride membrane were tailored. • Mid-drying facilitated the permeation flux and salt rejection of the membrane. • The membrane performance was susceptible to the phase transfer catalyst. Thin-film composite polyesteramide nanofiltration membrane prepared from carboxylated chitosan and trimesoyl chloride was carefully tailored during its fabrication process of interfacial polymerization. The effects of post-curing, mid-drying and the addition of phase transfer catalysts on the membrane properties were studied using single-factor experiment. Post-curing was found to be effective in improving the separation performance of the membrane containing high concentrations of carboxylated chitosan, and the optimal post-curing effect was achieved at a temperature of 40 °C and curing time range of 15−20 min. Mid-drying enhanced the permeation flux and salt rejection of the membrane containing low concentrations of carboxylated chitosan, and the optimum temperature range for the mid-drying process was obtained at 30−40 °C. Furthermore, the membrane properties were susceptible to the addition of phase transfer catalysts, and a uniformly distributed phase transfer catalyst is vital to its influence on membrane properties. The addition of 0.025 wt% benzyltriethylammonium chloride to the aqueous solution exhibited the best effect towards the improvement of the separation performance of the produced membrane. [ABSTRACT FROM AUTHOR]

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.)

A series of novel-sulfonated furanic polyesteramides have been synthesized by polycondensation in the melt-phase. The copolymers were obtained with reasonable molecular weights and high inherent viscosities between 0.2 and 0.4 dL/g. The hydrolytic degradability of polyesteramides was enhanced by the increasing of amide units in the copolymers backbone.

• A new concept of SIP was proposed for the preparation of PEA NF membranes. • The reactivity of hydramine could be activated by a trace amount of diamine. • The "hydramine-diamine" coupling unit acts as the reactive monomer. • The PEA membranes exhibited an improved salt rejection and considerable PWP. Polyester-amide (PEA) thin film composite (TFC) NF membranes have rapidly evolved towards a competitive performance, benefiting from their remarkable antifouling capability and superior chlorine resistance. In this report, a new concept of synergistic interfacial polymerization is explored, which promptly triggers the reaction between hydramines and trimesoyl chloride (TMC) in the presence of a trace amount of diamines. This rapid-start mode enables the formation of defect-free PEA films without the requirement of catalysis. A comprehensive characterization of physicochemical properties using high-resolution mass spectrometer (HRMS) reveals that the recombination and formation of a "hydramine-diamine" coupling unit plays a decisive role in activating the synergistic interfacial polymerization reaction with TMC molecules. Taking the pair of serinol and piperazine (PIP) as an example, the PEA-NF membrane fabricated with 0.1 w/v% serinol mixed with 0.04 w/v% PIP as water-soluble monomer and 0.1 w/v% TMC as oil phase monomer was found to have a pure water permeability (PWP) of 18.5 L·m−2·h−1·bar−1 and a MgSO 4 rejection of 95.5 %, which surpasses almost all the reported PEA NF membranes. Findings of the current research provide more possibilities for the low-cost and rapid synthesis of high-performance PEA membranes aiming for water purification. [ABSTRACT FROM AUTHOR]

[Display omitted] • • Degradable alternating polyamide hard segments and soft crystallizable segments were combined. • • These polyester amide elastomers (PEAEs) show excellent mechanical properties. • • PEAEs show fast degradation under mild conditions. • • PEAEs demonstrated outstanding processing capabilities. Degradable polymers typically require prolonged exposure to harsh conditions for degradation, but this extended duration and severe treatment often result in incomplete breakdown, leading to the formation of harmful microplastics that pose significant environmental pollution risks. In this work, degradable alternating polyamide hard segments and soft crystallizable segments were combined by amide groups to design thermoplastic bio-based polyesteramide elastomers (PEAEs) with customizable properties and rapid degradability. The hard segment of the polymer features an alternating arrangement of amide and ester bonds. This arrangement facilitates the formation of small molecule monomers when the ester bond is broken, preventing microplastic contamination that may arise from incomplete degradation of the hard segment. Additionally, the inclusion of side groups in the soft segment disrupts the crystallization, enhancing its susceptibility to solvent penetration and thereby accelerating the degradation rate. After step-cyclic tensile tests, additional physical cross-linking points were formed in PEAEs to enhance their mechanical strength and elasticity. Furthermore, PEAEs demonstrated outstanding processing capabilities, including compounding, extrusion, pelletization, and spinning. This innovative approach introduces fresh design concepts for the industrial application of bio-based degradable polymers, playing a pivotal role in advancing resource conservation and environmental protection. [ABSTRACT FROM AUTHOR]

Inflammation of the synovium and joint capsule is a main driver of pain in an osteoarthritic (OA) joint. Triamcinolone acetonide (TAA) is a classical corticosteroid that reduces synovitis and alleviates pain, albeit transiently. Biomaterial-based local TAA release may prolong the suppression of pain without the need for multiple injections. Polylactic-co-glycolic acid (PLGA) formulations of TAA prolong OA pain relief to a limited extent. A novel polyesteramide (PEA) microsphere platform allows for extended release in the OA joint for over 3 months. To evaluate their effect on pain and inflammation, TAA-loaded microspheres were intra-articularly delivered to the knee joint in a rat model of acute arthritis induced by intra-articular injection of streptococcal cell wall peptidoglycan-polysaccharide (PGPS) and subsequent flare-ups by intravenous PGPS injections. PEA-loaded microspheres were benchmarked with TAA-loaded PLGA microspheres and bolus TAA injection. TAA treatments were injected intra-articularly before the first induced flare-up. TAA-loaded PEA and PLGA microspheres reduced joint swelling and signs of pain-like behavior over the entire study period, as assessed by weight bearing and referred mechanical hypersensitivity, whereas bolus suspension was effective for a shorter time period. TAA-loaded PEA microspheres reduced lameness to a greater extent than TAA-loaded PLGA microspheres. In conclusion, a single intra-articular injection of TAA-loaded PEA microspheres reduced joint swelling and induced longer pain relief compared to bolus injection. Hence relief of inflammation and pain by PEA-based delivery of TAA may prove to be effective and durable.

The yellowing mechanism in polyesteramide based on poly(ethylene terephthalate) and polyamide 6 (PET‐PA6) has been studied. Amine model compounds were employed to react with acetaldehyde (AA), and 1H‐nuclear magnetic resonance spectrometer (1H‐NMR), fourier transform infrared spectroscopy (FT‐IR), and electrospray ionization mass spectrometry (ESI‐MS) were used to characterize the structure of the yellowing products. 13C‐NMR, laser confocal micro‐Raman spectrum, and X‐ray photoelectron spectroscopy (XPS) were used to characterize the yellowing products of the reaction of PA6 oligomers and AA. The structures of yellowing substances in the two systems are consistent. The color generation is mainly caused by the reaction of the terminal primary amine group of PA6 with AA, which is the thermal degradation product of PET, to form Schiff bases. These Schiff bases condense further to form a conjugated imine structure, which may be the main chromophore of polyesteramide. Due to the degradation of PA6 segments of the copolymer, it may further degrade to form new primary amino groups and increase yellowness during use. [ABSTRACT FROM AUTHOR]

A series of novel-sulfonated furanic polyesteramides have been synthesized by polycondensation in the melt-phase. The copolymers were obtained with reasonable molecular weights and high inherent viscosities between 0.2 and 0.4 dL/g. The hydrolytic degradability of polyesteramides was enhanced by the increasing of amide units in the copolymers backbone. [ABSTRACT FROM AUTHOR]

A series of random polyesteramides (PEAs) with a range of molar composition from 90/10 to 50/50 were synthesized by direct melt polycondensation of ε‐caprolactone and l‐alanine. Their structure was fully characterized by Fourier transform IR and NMR spectroscopy. The resulting copolymers are completely amorphous with the exception of PEA‐90/10 which possesses a semicrystalline structure. These PEAs present increasing glass transition temperatures at increasing l‐alanine contents and exhibit fairly good thermal stability with 10% mass loss temperatures reaching 315 °C. © 2020 Society of Industrial Chemistry [ABSTRACT FROM AUTHOR]

Thin film composite polyesteramide nanofiltration membranes were fabricated with interfacial polymerization from carboxylated chitosan and trimesoyl chloride on a microporous polysulfone support membrane. Salt rejection was improved by building a multiple-layer structure that was formed by sequentially repeating the cycles of the interfacial reactions. The chemical structure, surface morphology and charge were characterized for the polyesteramide top layer. The effects of the concentrations of the reactant solutions and the number of cycles of reactant depositions and reactions on the separation performance were investigated. The single-layer polyesteramide membrane produced from 3.5 wt% carboxylated chitosan and 0.7 wt% TMC has a negatively charged surface and shows favorable separation performance: pure water permeation flux of 7.3 L/(m2 h) at 0.6 MPa gauge feed pressure, and salt rejection of 95.0% for Na2SO4, 65.7% for MgSO4, 33.2% for MgCl2 and 66.3% for NaCl. The multiple-layer polyesteramide membranes show a more negatively charged surface and higher salt rejection than the single-layer polyesteramide membranes. The single-layer polyesteramide membrane PS-[(C-CS)1.0/TMC] with a relatively loose structure shows good retention for the reactive black 5 anionic dye. This study opens an interesting research area to explore a new type of thin film composite nanofiltration membrane. [ABSTRACT FROM AUTHOR]

Polyester-based membranes are entering into the limelight of prospective membrane technologies as a feasible alternative to conventional polyamide-based membranes for nanofiltration (NF). Various monomers, including β-cyclodextrin (β-CD) and triethanolamine (TEOA), among other hydroxyl terminated compounds, can be substituted for the monomer in aqueous solution during interfacial polymerization (IP) or even incorporated into what would normally be ultrafiltration (UF) membranes. When a polyester selective layer is fabricated, it presents distinct physicochemical properties and a loosening of the active layer compared to a conventional polyamide-based active layer that usually allows for greater water flux while still maintaining reasonable levels of salt/dye rejection. This review presents an overview of the mechanism that governs the formation of polyester-based membranes, discusses potential benefits and downfalls of such membranes for nanofiltration, and evaluates the practicability of various applications, including salt/dye separation, dye wastewater treatment, and more. [Display omitted] • Polyester-based membranes are entering into the limelight of prospective membrane technologies. • Cyclodextrin is a monomer that has pristine properties to enhance membrane performance. • Polyesteramide membranes incorporate both ester and amide groups in the active layer. • One of the advantages of polyester-based membranes is in membrane chlorine resistance. [ABSTRACT FROM AUTHOR]

Polyethylene terephthalate (PET) recycling has been carried out by various methods, e.g., mechanical recycling, chemical recycling, and energy recovery method. In this study, chemical recycling of PET was carried out by aminolysis using ethanolamine and converted into bis(2-hydroxyethyl) terephthalamide (BHETA). We have studied the effective polymeric catalysis of the aminolytic depolymerization of waste polyethylene terephthalate (PET) using sulfated polyborate producing a broad range of crystalline terephthalamides. The reaction was performed by varying the PET: ethanolamine ratio, reaction time and catalyst. Recycled PET bottles, film, and fibres were used for conversion. A yield of 95 % was obtained for PET: ethanolamine ratio of 1:4 (w/w), with 4 h reaction time, at 160 o C with sulfated polyborate as a catalyst. BHETA was characterized with FTIR, 1H,13C NMR, and DSC analysis. BHETA further gets reacted with dimer acid along with Ethylenediamine (EDA) at different molar ratios which produces polyesteramide (PEA) based hot melt adhesive (HMA). Thermal, mechanical, and rheological tests are performed and compared with traditional HMA. The effect on the properties of the hot melt adhesive, such as mechanical properties: tensile strength, shore D hardness, elongation at break; thermal properties: glass transition temperature (Tg), melting temperature (Tm), the heat of crystallization (Hc), crystallization temperature (Tc); adhesion properties: lap shear strength (LSS) and T-peel strength (TPS); rheological properties and degree of crystallinity were investigated. It was observed that the mechanical and thermal properties are increased by optimizing the concentration of BHETA. These HMA materials may have the capacity of being eco-friendly and have high adhesion properties. [ABSTRACT FROM AUTHOR]

Inflammation of the synovium and joint capsule is a main driver of pain in an osteoarthritic (OA) joint. Triamcinolone acetonide (TAA) is a classical corticosteroid that reduces synovitis and alleviates pain, albeit transiently. Biomaterial-based local TAA release may prolong the suppression of pain without the need for multiple injections. Polylactic-co-glycolic acid (PLGA) formulations of TAA prolong OA pain relief to a limited extent. A novel polyesteramide (PEA) microsphere platform allows for extended release in the OA joint for over 3 months. To evaluate their effect on pain and inflammation, TAA-loaded microspheres were intra-articularly delivered to the knee joint in a rat model of acute arthritis induced by intra-articular injection of streptococcal cell wall peptidoglycan-polysaccharide (PGPS) and subsequent flare-ups by intravenous PGPS injections. PEA-loaded microspheres were benchmarked with TAA-loaded PLGA microspheres and bolus TAA injection. TAA treatments were injected intra-articularly before the first induced flare-up. TAA-loaded PEA and PLGA microspheres reduced joint swelling and signs of pain-like behavior over the entire study period, as assessed by weight bearing and referred mechanical hypersensitivity, whereas bolus suspension was effective for a shorter time period. TAA-loaded PEA microspheres reduced lameness to a greater extent than TAA-loaded PLGA microspheres. In conclusion, a single intra-articular injection of TAA-loaded PEA microspheres reduced joint swelling and induced longer pain relief compared to bolus injection. Hence relief of inflammation and pain by PEA-based delivery of TAA may prove to be effective and durable. [ABSTRACT FROM AUTHOR]

The purpose of the work is to study the mechanical properties and compatibility of binary blends obtained from polyamide 6 and polyamide 11 with a polyesteramide derived from tartaric and succinic acids with an ester content of 10 %. We have tried to obtain a new material, combining the mechanical characteristics of commercial polyamides with the degradability of polyesteramide for use with biomedical purposes, in suture threads. The blends were prepared by melting and the compatibility was evaluated by optical microscopy. The mechanical properties of these systems were obtained by tensile tests. The mechanical characteristics of the obtained blends are diminished with respect to the average value of the components, which verifies the incompatibility observed by optical microscopy; this behavior corresponds to incompatible polymer systems, which limits its use for biomedical purposes. [ABSTRACT FROM AUTHOR]

We have synthesized and characterized a new family of nematic all-aromatic polyesteramide thermosets based on 6-hydroxy-2-naphthoic acid (HNA), terephthalic acid (TA), and 4-acetamidophenol (AAP). In order to incorporate a high concentration of the amide-based monomer (AAP), the melt transition (T K-N) and melt viscosity had to be lowered in order to maintain melt processable intermediates. Precursor thermoplastic reactive oligomers, end-capped with phenylethynyl functionalities, were prepared using standard melt condensation techniques with a target M n of 1000–9000 g mol−1. The reactive oligomers with 20–30 mol% AAP could easily be processed into films, and the films exhibit good tensile properties in terms of tensile strength (70–80 MPa) and elongation at break (7–10%). A glass transition of 191°C could be obtained when a 1000 g mol−1 oligomer (HNA/TA/AAP(20)–1 K) was thermally cross-linked. When the AAP concentration reaches 35 mol%, the rigidity of the backbone and the hydrogen bonding interactions are enhanced, which make HNA/TA/AAP(35) polymers difficult to process. [ABSTRACT FROM AUTHOR]

Renewable source based anticorrosive and antimicrobial polyesteramide polyols were synthesized by reacting algae oil with diethanolamine and thio diacids viz. mercaptosuccinic (MSA) and thiodipropionic (TPA) acids. The confirmation of structures and molecular weights of prepared polyols were done by 1H NMR and FTIR spectroscopic techniques, and size exclusion chromatography (SEC), respectively. The polyols were used to prepare PU which showed excellent adhesion (100%) as compared to algae oil fatty amide (AOFA) (88%) high gloss (118 and 115). This PU passed flexibility test and showed good chemical resistance in comparison to the AOFA based PU coatings. The prepared PU coatings were checked for the anticorrosive property by dipping and electrochemical method performed against 3.5 wt% NaCl and 5 wt% HCl corrosive media. The PEA- PU possessed lower corrosion rate (mm/year) and I corr values as well as high polarization resistance (R p) and inhibition efficiency, than uncoated (blank) and AOFA based PU (PU-AOFA). Both MSA and TPA based PU coatings showed good antimicrobial potential and reduction in bacterial attachment, against Gram - negative (E. coli) and Gram - positive (S. aureus) bacteria in comparison to the control and AOFA PU coatings as observed through SEM and the thermal stability of modified PUs was also improved. Unlabelled Image • Algae oil, mercaptosuccinic and thiodipropionic acids based polyols was used as surface coatings. • Bio-based polyurethane coatings are prepared using polyols. • Polyurethane coatings showed superior corrosion resistance property in salt and acid corrosive media for mild steel. • The polyurethane coatings showed good anti-microbial, chemical resistance, and adhesion properties. • Algae oil and thio acids are ability to substitute conventional petroleum based raw materials in surface coating industry. [ABSTRACT FROM AUTHOR]

Reverse osmosis is an effective seawater desalination way extending the available sources of fresh water, but challenged by the gypsum scaling. Herein, D (+)-glucosamine (DGA) was rationally selected and utilized to prepare a novel polyesteramide (PEA) NF membrane that can reject SO 4 2− but release Ca2+. Then it was employed in the pretreatment of seawater reverse osmosis to spatially isolate SO 4 2− and Ca2+, thus removing the "foundation" for forming gypsum. Compared to the referenced NF270, the optimized sample denoted as DGA-PEA-NF has a looser structure with stronger negative charge, as well as a higher resistance to both organic fouling and chlorine attack. During the pretreatment of seawater, both the water permeability and SO42−/Ca2+ selectivity of the DGA-PEA-NF membrane were much higher than those of NF270; the seawater permeance and SO 4 2−/Ca2+ selectivity of DGA-PEA-NF were 10.25 L m−2·h−1·bar−1 and 7.62, respectively, while those of NF270 were only 5.11 L m−2·h−1·bar−1 and 2.08. Consequently, the DGA-PEA-NF membrane effectively reduced the gypsum scaling both in NF and RO stages rather than just transferring the fouling problem forwards to NF stage. The implementation of this research is expected to provide guidance for a targeted fabrication of NF membranes, as well as support for the sustainable development of seawater desalination. [Display omitted] • A novel polyesteramide NF membrane was prepared with D (+)-glucosamine as monomer. • The optimized DGA-PEA-NF membrane showed a high SO 4 2−/Ca2+ selectivity. • DGA-PEA-NF membrane showed high resistance to organic fouling and chlorine attack. • Novel "NF + RO" seawater desalination process was formed with DGA-PEA-NF membrane. • The gypsum scaling/fouling in both NF and RO could be significantly alleviated. [ABSTRACT FROM AUTHOR]

The synthesis of polyesters and polyamides by enzyme-catalyzed processes in vitro was developed in the last decades as a green alternative to obtain biodegradable synthetic polymers with various applications, such as nanoparticle-sized carriers for drug delivery. Polyesteramides were much less studied in this respect, although having the presumable advantage of increased mechanical and thermic resistance brought by the amide moieties. In this work, polyesteramides were synthesized for the first time employing as raw materials ε-caprolactam and a hydroxy acid. L-malic, 3-hydroxybutyric, 12-hydroxystearic and 16-hydroxyhexadecanoic acid, respectively, were investigated as co-monomers in solventless or organic medium, using the immobilized lipase Novozyme 435 as catalyst. The short chain hydroxy acids holding secondary hydroxyl groups yielded oligomers with average degree of polymerization no higher than 4, while in the case of the long-chain 12-hydroxystearic acid this value increased to 7. The best results were achieved by using 16-hydroxyhexadecanoic acid in 2:1 M excess at 80 °C, yielding a product with 75% copolymer content and average molecular weight higher than 3000 Da. The emulsion-solvent evaporation method allowed the efficient production of nanoparticles based on this copolymer, with sizes around 230 nm, used for the encapsulation of a model bioactive compound, the anticancer drug sorafenib. Production yields of >70% and encapsulation efficiencies of around 60% are very promising for further development of this approach. [Display omitted] • Four novel bio-based polyester amides were enzymatically synthesized. • The properties of the enzymatically synthesized PEA's can be fine-tuned. • Nanosized drug carrier formulations were obtained using the 16HHDA based PEAs. [ABSTRACT FROM AUTHOR]

Recycling of poly(ethylene terephthalate) (PET) is a global concern due to generation of large volume of its post consumer waste and serious environmental problems caused as PET does not decompose in nature readily. Present research work aims at effective recycling of waste PET from soft drink bottles by aminolysis method and further utilization of the recycled product for high performance coating application. In the present study, we report aminoethylenethanolamine (AEEA) which till date is not studied much for chemical recycling of PET, having primary and secondary amine groups together with hydroxyl groups, for aminolysis reaction. The reaction parameters were optimized for conventional and microwave assisted technique by varying the ratio of raw materials, reaction time, temperature and power. The recycled oligomeric product was separated, purified and characterized for determination of amine value, hydroxyl value and by Fourier transform infrared spectroscopy, proton NMR (1H-NMR) spectroscopy. Further polyesteramides were successfully synthesized by partial replacement of neopentyl glycol by aminolyzed oligomeric product along with sebacic acid and phthalic anhydride. These resulting polyesteramides were further cured with commercial polyisocyanate curing agents and applied on mild steel panels. The cured coatings were evaluated for their optical, mechanical, chemical, thermal and anticorrosive properties. The partial replacement of recycled product of PET wastes exhibited comparative coating performance properties with respect to polyester polyol synthesized without any component based on recycled PET waste product. [ABSTRACT FROM AUTHOR]

In order to prepare furanic-aliphatic polyesteramides without the side reactions taking place with furan-2-carboxylic acids or esters, a furan-based diamine, 5,5'-isopropylidenebis(2-furfurylamine), was reacted in the bulk, either with (i) ethanediol and dimethyl adipate or (ii) with the corresponding aliphatic polyester (polyethylene adipate). The polycondensation involves both amine-ester and hydroxy-ester interchanges, with elimination of excess ethanediol. High-molar-mass furanic-aliphatic polyesteramides were easily obtained. Method (ii) was more efficient than method (i), but no side reactions were observed with both methods. These polyesteramides behave as amorphous random copolymers. [ABSTRACT FROM AUTHOR]

ABSTRACT Palm stearin-based polyesteramide (PSPEA) was synthesized by reacting PS with diethanolamine, followed by azelaic acid at functionality molar ratio (OH: COOH) ranged 1:0.84 to 1:0.95 at 150-190 °C. FTIR, 1H-nuclear magnetic resonance, 13C-nuclear magnetic resonance, and gel permeation chromatography were used to elucidate the chemical structure and Mw distribution of the PSPEA. PSPEA 4000 (acid value = 0.61 mg KOH/g sample, hydroxyl value = 51.97 mg KOH/g sample) was used in combination with stearic acid-based PEA to prepare mefenamic acid (MA) solid dispersion. The solid dispersion demonstrated sixfold and twofold enhancement in T50% and cumulative drug release as compared to pure MA. The differential scanning calorimetry and scanning electron microscopy analyses revealed solubilization of MA in PEA and transformation of MA into amorphous. In vitro cytotoxicity studies confirmed the safety profile of PSPEA against 3T3 fibroblast cell lines. This work demonstrated that the biocompatible PSPEA possesses surface tension lowering and anticrystallization effects have the potential as polymer carrier for pharmaceutical dosage forms. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45892. [ABSTRACT FROM AUTHOR]

Using the melt polycondensation method, a polyesteramide was prepared based on poly(L-lactic acid) prepolymer and poly(ε-caprolactam) prepolymer and was characterized by Fourier transform infrared spectroscopy and 1H-NMR. Isothermal crystallization behavior at different temperatures and non-isothermal crystallization kinetics at different cooling rates were investigated by differential scanning calorimetry, and non-isothermal crystallization kinetics parameters were obtained using the Mo, Ozawa and Jeziorny methods. It was found that the increased cooling rates led to the broadening of the polyesteramide crystallization peaks and their shift toward lower temperatures. Mo and Jeziorny methods were found to be more suitable than the Ozawa method for the analysis of this system, as shown by the comparison these non-isothermal crystallization analysis methods. In addition, the values of activation energy of non-isothermal crystallization for polyesteramide obtained by the Kissinger and Takhor methods were -155.96 and -149.12 kJ/mol, respectively. [ABSTRACT FROM AUTHOR]

In order to integrate the advantages of polyamide thin film composite (TFC) nanofiltration (NF) membranes and that of polyester TFC NF membranes, a novel polyesteramide (PEA) TFC NF membrane was prepared by interfacial polymerization between serinol and trimesoyl chloride (TMC) and catalyzed by 4-dimethylaminopyridine (DMAP) on a flat-sheet polyethersulfone (PES) substrate membrane. The membrane performance was maximized by optimizing different preparation parameters. The reaction process was divided into four basic patterns. X-ray photoelectron spectroscopy (XPS) and infrared spectroscopy confirmed the membrane had a partially cross-linked active layer that contained ester bonds, amide bonds and residual hydroxyl groups. Morphology analysis showed the surface of the PEA-TFC-NF membrane was grainy, which was different from the typical polyamide membranes. The contact angle and zeta potential measurements confirmed the PEA-TFC-NF membrane was highly hydrophilic and negatively charged across the entire pH range tested. The optimized PEA-TFC-NF membrane had a MWCO of 474 Da and water permeability of 6.0 L m −2 h −1 bar −1 at 0.5 MPa and 25 °C. The membrane salt rejections followed the order of Na 2 SO 4 > MgSO 4 > NaCl > MgCl 2 , which were 96.27%, 83.92%, 58.68% and 28.76%, respectively. Moreover, the PEA-TFC-NF membrane displayed good antifouling ability. [ABSTRACT FROM AUTHOR]

Jatropha oil (JO) is an inedible oil mainly used in biodiesel. We have attempted to prepare a JO-based polyesteramide/clay composite using a one-pot, two-step reaction, for application as a protective coating. The aim of the work is to utilize JO for its value-added application by preparing a JO polyesteramide/clay composite, to investigate the potential of the prepared composite as a protective coating, and also to study the effect of loaded clay on the structure, morphology, thermal stability and coating properties of the composite. The formation of composites was confirmed by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and atomic force microscope (AFM) studies. The coating properties were studied by standard physicomechanical and corrosion resistance tests in corrosive media (3.5 wt% HCl, 3.5 wt% NaCl and tap water). The thermal stability was assessed by differential scanning calorimetry (DSC), thermogravimetric (TGA) and derivative thermogravimetric (DTG) analyses. The coatings showed good physico-mechanical and corrosion resistance performance and can be safely used up to 275°C. The approach paves way towards an alternate value addition to a non-edible oil. [ABSTRACT FROM AUTHOR]

This pre-formulation study assays the capacity of the polyesteramide PADAS, poly (L-alanine-dodecanediol-L-alanine-sebacic), as an insoluble tablet excipient matrix for prolonged drug release. The flow properties of PADAS were suitable for tableting, and the compressibility of tablets containing exclusively PADAS was evaluated by ESEM observation of the microstructure. The tablets were resistant to crushing and non-friable and they did not undergo disintegration (typical features of an inert matrix). Tablets containing 33.33% sodium diclofenac (DF), ketoprofen (K) or dexketoprofen trometamol (DK-T) as a model drug, in addition with 66.67% of polymer, were formulated, and the absence of interactions between the components was confirmed by differential scanning calorimetry. Dissolution tests showed that PADAS retained DF and K and prolonged drug release, following a Higuchi kinetic. The tablets containing DK-T did not retain the drug sufficiently for prolonged release to be established. Tablets containing DK-T and 66.67, 83.33 or 91.67% PADAS, compressed at 44.48 or 88.96 kN, were elaborated to determine the influence of the polymer amount and of the compression force on DK-T release. Both parameters significantly delayed drug release, except when the proportion of polymer was 91.67%. [ABSTRACT FROM AUTHOR]

Polyesteramides (PEAs) are considered intriguing materials due to the combination of the favorable degradable capacity of aliphatic polyesters given by the hydrolizable ester groups and the desirable thermal and mechanical behavior of polyamides given by the amide groups. Between polyamides and polyester families, poly(ε-caprolactam) and poly( l -lactide) stand out due to their commercial value and outstanding properties. Nevertheless, to date these two monomers have not been co-polymerized due to their different reactivities. In this work, we report for the first time, up to our knowledge, the synthesis of poly(ε-caprolactam- co - l -lactide) copolymers with different compositions. Two different catalysts: (a) Brønsted acid ionic liquid 1-(4-sulfobutyl)-3-methylimidazolium hydrogen sulfate (BAIL) and (b) Brønsted base P 4 - t -Bu have been explored. In the presence of Brønsted acid the l -lactide reactivity is higher than the ε-caprolactam while in the presence of Brønsted base the opposite behavior is observed. Using Kelen-Tudos method the monomer reactivity ratios are calculated and obtained as r CLa = 0.39 and r LA = 1.6 and r CLa = 2.2 and r LA = 0.1 using BAIL and P 4 - t -Bu, respectively. These differences in the monomer reactivity ratios give us the possibility to create copolymers with different chain microstructure depending on the employed catalyst between 2 and 9 kDa. Thus, using P 4 - t -Bu random copolymers can be obtained at high l -lactide concentration and blocky character copolymers at high ε-caprolactam concentration. Meanwhile, using BAIL catalyst random like copolymers are obtained at high ε-caprolactam contents and blocky character at high l -lactide contents. [ABSTRACT FROM AUTHOR]

We described preparation of composites of graphene oxide with copolymers containing ε-caprolactam and ε-caprolactone structural units. Graphene oxide was prepared using modified Hummers method and characterized by elemental analysis and X-ray photoelectron spectroscopy measurements, interlayer distance was evaluated from X-ray diffraction. Two types of copolymers - polyesteramides - with molar ratio of ε-caprolactam to ε-caprolactone units in polymerization feed 80/20 and 90/10 were prepared by polymerization casting method. Graphene oxide content in both types of polyesteramides was in range from 0.1 to 1 wt.%. Thermogravimetric analysis and differential scanning calorimetry were utilized to study thermal stability and crystallization behaviour of materials. Prepared composites were characterized by tensile modulus and impact strength. Rheological properties of polymer melts and viscometry of diluted polymer solutions revealed the physical character of polymer-filler interactions. [ABSTRACT FROM AUTHOR]

Bio-based thermoset polyurethane (PU) coatings comprised of polyesteramides were prepared from Gossypium arboreum (cotton seed) plant oil as a renewable source. Oil was first converted into fatty amide that was transformed into a series of polyesteramide polyols upon esterification with different dicarboxylic acids and anhydride. In the preparation of polyesteramide polyols, to increase bio-based content five different dicarboxylic acids of renewable nature were used to replace petroleum counterparts. Structures of polyols were confirmed using NMR and FT-IR spectroscopic techniques. Molecular weights of polyols were determined using gel permeation chromatography. Bio-based polyesteramide polyols were used to prepare thermoset PU by treating with aromatic diisocyanate. The thermal behavior of all prepared polyurethane coatings was determined using a thermogravimetric analyzer and differential scanning calorimeter. Coatings prepared using renewable source based polyesteramides were with high suitable curing, mechanical/chemical performances, alkali/acid resistance, and hydrophobicity. Compared to conventional PU coatings, the prepared coatings possess the superior properties such as gloss, adhesion, and pencil hardness. Thus present work demonstrates Gossypium arboreum plant oil and dicarboxylic acids as newer eco-friendly raw materials for PU coatings and compared with standard petro based polyols. [ABSTRACT FROM AUTHOR]

Two series of bio-based diaminopentane hexanedioic salt (DHS) modified polyesteramides were successfully synthesized by two different synthesis processes in which DHS reacted with bis-hydroxyethyl terephthalate (BHET) and low molecular weight polyester (LPET), respectively. The intrinsic viscosities of the polyesteramides ranged from 0.62 dl/g to 0.78 dl/g, which correlated greatly with the requirements of subsequent processing such as spinning. The results of the heteronuclear multiple bond correlation (HMBC) indicated that the diaminopentane segment was directly connected with the purified terephthalic acid (PTA) segment. The presence of ester and amide group characteristic peaks in the Fourier transform-infrared (FT-IR) spectroscopy confirmed that the final resultant products were polyesteramides. The results of elemental analysis showed that the ratio of actual nitrogen content to theoretical nitrogen content of two series of polyesteramides was 76%~90%, and the actual nitrogen content in both series was proportional to the addition of DHS. [ABSTRACT FROM AUTHOR]

[Display omitted] • Two novel polyesteramide NF membranes were prepared via IP by amino-alcohol monomers. • The THAM-TFC membrane showed high permselectivity (17.7 LMH/bar, 98.0% of Na 2 SO 4). • The relationship between monomer structure and membrane performance was elaborated. • Comparison of two PEA membranes to provide new insights into monomer selection. Although polyesteramide (PEA) nanofiltration membranes exhibit multi-functionalities such as superior antifouling property and chlorine resistance, their low water permeability poses a major impediment for water treatment. In this study, new PEA-based thin film composite (TFC) membranes were constructed by utilizing the amino-alcohol monomers [tris(hydroxymethyl)aminomethane: THAM, and 2-amino-2-methyl-1,3-propanediol: AMPD)] via interfacial polymerization (IP) with trimesoyl chloride (TMC). The THAM monomers with one more hydroxyl group endow the synthesized TFC membranes with higher hydrophilicity and more negative charges contrasted to AMPD-TFC membranes. Interestingly, the AMPD containing non-polar methyl groups were found to attain more compact TFC membranes with a MWCO of 579 Da. This is because more rapid diffusion of AMPD toward the organic phase promotes a more adequate IP reaction, leading to high-crosslinked membranes with smaller pore sizes. The resulting THAM-TFC membrane with a larger pore size exhibit a high water permeability (17.7 LMH bar−1), and superior salt rejection (Na 2 SO 4 : 98.0 %), outperforming the reported polyester NF membranes. Due to the inactive chlorination reaction site of the polyester group, the PEA membranes exhibited stable separation performance after immersion in a harsh chlorine environment up to 96 h. This study comprehensively compared the effects of two structural-similar monomers on membrane structures and performance, providing a guidance of using suitable monomers to fabricate the high-flux NF membranes. [ABSTRACT FROM AUTHOR]

Polyesters derived from the α-hydroxy acids, lactic acid, and glycolic acid, are the most common biodegradable polymers in clinical use. These polymers have been tailored for a range of applications that require a physical material possessing. The physical and mechanical properties of these polymers fit the specific application and also safely biodegrade. These polymers are hydrophobic and do not possess functional side groups. This does not allow hydrophilic or hydrophobic manipulation, conjugation of active agents along the polymer chain, etc. These manipulations have partly been achieved by block copolymerization with, for example, poly(ethylene glycol), to obtain an amphiphilic copolymer. The objective of this review is to survey PLA functional copolymers in which functional α-hydroxy acids derived from amino acids are introduced along the polymer chain, allowing endless manipulation of PLA. Biodegradable functional polyesters are one of the most versatile biomaterials available to biomedical scientists. Amino acids with their variable side chains are ideal candidates for synthesizing such structural as well as stereochemically diverse polymers. They render control over functionalization, conjugation, crosslinking, stimulus responsiveness, and tunable mechanical/thermal properties. Functionalized amino acid derived polyesters are widely used, mainly due to advancement in ring opening polymerization (primarily O -carboxyanhydride mediated). The reaction proceeds under milder conditions and yields high molecular weight polymers. We reviewed on advances in the synthetic methodologies for poly-α-hydroxy esters derived from amino acids with appropriate recent examples. [ABSTRACT FROM AUTHOR]

In accordance to synthesis of sustainable coating, the carboxyl terminated Polyesteramide resin is synthesized from fatty amide of palm oil. To improve the performance of the coating the ZnO-Al 2 O 3 -fly ash composite and functional Multiwall Carbon nanotubes (MWCNTs) were added to the system. The ZnO-Al 2 O 3 -fly ash composite was treated with amine-silane to develop the amino functionality on the periphery. The MWCNT’s were treated to develop the carboxyl functionality. The presence of functionality on the ZnO-Al 2 O 3 -fly ash composite and MWCNT enable the chemical bonding of same to the coating matrix, improving the performance of the coating. ZnO-Al 2 O 3 - fly ash composites were characterised by FTIR, SEM analysis and XRD to confirm the modification. Also singular and synergistic effect chemically bonded nanocomposite to the coating system was studied by varying the composite ratio as 5% (w/w) & 10% (w/w), MWCNTs ratio individually 0.25% (w/w) & 0.5% (w/w) and in combination of both. The anticorrosive properties were improved, impedance value increases from 100 M (ohms) to 10 G (ohms) in EIS measurement. As well as hardness of the coating increases from H to 4H, scratch resistance increases from 2 kg to 3.1 kg. [ABSTRACT FROM AUTHOR]

Polyesteramide multiblock copolymers based on polyamide 6 and diepoxy propylene adipate blocks were synthesized. For this purpose a carboxyl-terminated polyamide 6 ( M n = 2400 g/mol, T m = 205.5 °C) and diepoxy propylene adipate ( M n = 450 g/mol) were separately synthesized and characterized. The incorporation of the oligoester into the polyamide 6 backbone was performed by solid state polymerization (SSP) well below the melting temperature of the polyamide (80–140 °C) so that the physical and thermal properties of the original polyamide 6 block were retained. Formation of the multiblock structure was confirmed by following the increase in molecular weight by SEC, reaction of the end groups by 1 H NMR and by following the maintained melting temperature after the copolymerization. These segmented copolymers have molecular weights up to 10 kg/mol, thermal stability of 325 °C at 5% weight loss and a melting temperature of 205 °C. [ABSTRACT FROM AUTHOR]

In this study, ethylene glycol polyesteramide (Eg-PEA) was synthesized fromN,N-bis (2-hydroxy ethyl) pongamia oil fatty amide and ethylene glycol tetraacetic acid (EGTA) through condensation polymerization. It was further modified by toluene 2,4-diisocynate in different wt.% (20, 25, 30, and 35) to obtain urethane-modified polyesteramide (Eg-UPEA). The synthesized resins were characterized using FT-IR,1H NMR, and13C NMR spectroscopic techniques, and molecular weight was determined by gel permeation chromatography (GPC). Physico-chemical and physico-mechanical analyses were carried out by standard laboratory methods. Thermal studies of Eg-UPEA were undertaken by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) techniques. To evaluate corrosion prevention performance Eg-UPEA-coated mild steel strips were investigated by potentiodynamic polarization in different corrosive media (5 wt.% NaCl, 3 wt.% HCL, 2.5 wt.% NaOH, and tap water) at room temperature. Thermal analysis revealed that Eg-UPEA30 may find application as an environmentally friendly corrosion protective coating and may be safely used up to 250°C. [ABSTRACT FROM AUTHOR]

[Display omitted] • The PA, PEA and PE membranes were prepared and compared, respectively. • Comparable rejection of organic solutes could be achieved by different membranes. • Different morphological structures of PA, PEA and PE active layers were observed. • The role of positive charges of the active layers on the ion rejection was defined. In this study, three different kinds of nanofiltration membranes with polyamide (PA), polyesteramide (PEA), and polyester (PE) active layers were respectively synthesized by using piperazine, serinol and meso -erythritol as the aqueous monomers for interfacial polymerization. The three types of membranes achieved comparable rejections for the reference organic solute (i.e., xylose) via optimization of preparation conditions, based on which the characteristics of different active layers were comprehensively investigated. Results showed that the PA, PEA and PE membranes exhibited distinct surface morphologies. The special surface structures of PEA membranes and the larger active layer thickness of PE membranes resulted in their lower water permeance compared to PA membranes. Different from PA active layers, the absence of positively charged regions in the PEA and PA active layers was beneficial for the passage of divalent cations and the rejection of NaCl. Moreover, despite the comparable mean pore size, PA membranes exhibited a more uniform membrane pore size resulting in a higher rejection of organic matters in natural water than PEA and PE membranes. This study presented the differences in physicochemical properties and separation performance among the different membrane active layers, which could provide references for the rational selection of nanofiltration membrane types during application. [ABSTRACT FROM AUTHOR]

The highlight of the work was the preparation of polyesteramide in a one-pot reaction which avoids isolation of diethanol amide as it is normally required in polyesteramide preparation. In the present work, oleic acid was reacted with diethanol amine resulting in diethanol amide which further reacted with phthalic anhydride in the same reaction vessel without isolation and purification. Therefore the reaction is a one-pot, time-saving and cost-effective method as it requires minimum solvent and processing steps. In addition to this, the fatty acid used was a single fatty acid (oleic acid) that provides selective physico- chemical and anticorrosive properties for the resin. FT-IR and H-NMR spectroscopic studies confirmed the structure of the polyesteramide. End group analysis and molecular weight were used to calculate the stoichiometric balance of the NCO/OH ratio in the preparation of polyurethane. The prepared resin was converted to polyurethane coatings by reacting with toluene diisocyanate and methylene diphenyl diisocyanate. Thermal stability, physico-chemical and coating properties of the polyurethane coatings were investigated. The polyurethane prepared showed a non-biodegradable nature so that it is of commercial interest and value for applications in various fields. Study of coatings was also carried out for properties like adhesion, impact resistance, pencil hardness and the bending test. [ABSTRACT FROM AUTHOR]

Highlights: [•] Conducting polymer composite coatings. [•] Superior protection in aggressive environments. [•] Cost effective and eco-friendly. [•] Protection through barrier mechanism. [•] Improved lifetime and serviceability. [Copyright &y& Elsevier]