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Pyrone-2,4-dicarboxylic acid (PDC) is a valuable polymer precursor that can be derived from the microbial degradation of lignin. The key enzyme in the microbial production of PDC is 4-carboxy-2-hydroxymuconate-6-semialdehyde (CHMS) dehydrogenase, which acts on the substrate CHMS. We present the crystal structure of CHMS dehydrogenase (PmdC from Comamonas testosteroni) bound to the cofactor NADP, shedding light on its three-dimensional architecture, and revealing residues responsible for binding NADP. Using a combination of structural homology, molecular docking, and quantum chemistry calculations, we have predicted the binding site of CHMS. Key histidine residues in a conserved sequence are identified as crucial for binding the hydroxyl group of CHMS and facilitating dehydrogenation with NADP. Mutating these histidine residues results in a loss of enzyme activity, leading to a proposed model for the enzyme's mechanism. These findings are expected to help guide efforts in protein and metabolic engineering to enhance PDC yields in biological routes to polymer feedstock synthesis.

The growing demand for energy‐storage devices has raised inevitable concerns regarding the availability of redox‐active inorganic compounds and metals. It is expected that some of the inorganic compounds will be replaced by organic redox polymers, which are produced from abundant sources using environmentally benign processes, and they exhibit inherent advantages, including flexibility, processability, and biocompatibility. Redox polymers contain groups that can be reversibly reduced and oxidized by gaining and releasing electrons, respectively, and constitute an emerging class of functional organic materials. This article begins with a retrospective discussion of polymers and their electron exchange concepts, presenting them as old but new materials. The basics of electrochemical redox couples are briefly reintroduced, and the chemical design strategies for extending them to redox polymers are summarized. Subsequently, the efficient and reversible charge propagation and storage in densely populated redox‐active sites on soft polymer platforms are discussed. The potential to employ redox polymers in rechargeable charge‐storage applications and next‐generation devices is discussed, along with the current challenges and prospects. This outlook suggests fundamental questions and proposes interesting topics for redox polymers to facilitate their development as valuable materials for use in sustainable technologies. [ABSTRACT FROM AUTHOR]

The electrolysis of aromatic molecules is a useful method for the synthesis and deposition of conducting polymers. However, this method cannot be applied to diverse large‐area electronic devices because films grow vertically on the surface of an electrically connected working electrode. Herein, the remote‐controllable lateral electropolymerization of 3,4‐ethylenedioxythiophene using direct‐current voltage superimposed alternating‐current voltage (ADC)‐bipolar electrochemistry is reported. The use of shape‐designed dual bipolar electrodes and systematic optimization of the process parameters led to the fabrication of uniform poly(3,4‐ethylenedioxythiophene) (PEDOT) films on 2‐inch glass wafers and flexible plastic substrates. The oxidation levels and microstructures of ADC‐electropolymerized PEDOTs with various supporting electrolytes are investigated and correlated with their thermoelectric properties. A soft thermocouple and resistive‐type gas sensor based on an ADC‐electrodeposited PEDOT are demonstrated to monitor cerebral temperature in a brain replica and to sense nitrogen dioxide gas, respectively. [ABSTRACT FROM AUTHOR]

Recent years have witnessed the transformative impact from the integration of artificial intelligence with organic and polymer synthesis. This synergy offers innovative and intelligent solutions to a range of classic problems in synthetic chemistry. These exciting advancements include the prediction of molecular property, multi-step retrosynthetic pathway planning, elucidation of the structure-performance relationship of single-step transformation, establishment of the quantitative linkage between polymer structures and their functions, design and optimization of polymerization process, prediction of the structure and sequence of biological macromolecules, as well as automated and intelligent synthesis platforms. Chemists can now explore synthetic chemistry with unprecedented precision and efficiency, creating novel reactions, catalysts, and polymer materials under the data-driven paradigm. Despite these thrilling developments, the field of artificial intelligence (AI) synthetic chemistry is still in its infancy, facing challenges and limitations in terms of data openness, model interpretability, as well as software and hardware support. This review aims to provide an overview of the current progress, key challenges, and future development suggestions in the interdisciplinary field between AI and synthetic chemistry. It is hoped that this overview will offer readers a comprehensive understanding of this emerging field, inspiring and promoting further scientific research and development. [ABSTRACT FROM AUTHOR]

This study presents a novel approach to modifying copolymers with active azide end-groups through click chemistry, specifically targeting the incorporation of cysteine amino acid. The synthesis commenced with the reaction between cysteine amino acid and propargyl amine, yielding the alkyne-terminated amino acid Boc-Cys(Bnz)-PA compound. Through the click chemistry methodology, the copolymer with active azide ends was modified with alkyne-terminated Cys-PA. Thermal characterization of the copolymers was performed via differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). DSC measurements revealed an increase in glass transition temperature (Tg) from 65 °C to 83 °C upon the modification with cysteine, indicating enhanced thermal stability. However, TGA data suggested a decrease in thermal stability as evidenced by lower initial degradation temperatures for the modified copolymer compared to the unmodified counterpart.The degradation activation energies of the copolymers were estimated using the Flynn-Wall-Ozawa method across various conversion ranges, demonstrating higher thermal degradation activation energy for the modified copolymer compared to the unmodified one. Dielectric behavior analysis conducted at room temperature over a frequency range from 100 Hz to 20 kHz revealed a decreasing trend in dielectric constant and dielectric loss values with increasing frequency for all copolymer structures. The alternating current (AC) conductivities at 30 kHz were calculated as 1.84 × 10−7 S cm−1, and 4.75 × 10−7 S cm−1 for P(VBCl-co-VBN3 0.77) and (P(VBCl-co-(VBN3-click-Cys)0.77), respectively, indicating a frequency-dependent conductivity enhancement with increasing frequency. Overall, the results suggest that these polymeric materials, containing amino acid structures, hold promise as dielectric materials for low-frequency and low-voltage devices such as sensors, owing to their tunable thermal and dielectric properties achieved through click chemistry modification. [ABSTRACT FROM AUTHOR]

Our society has been pursuing high‐performance biodegradable polymers made from facile methods and readily available monomers. Here, we demonstrate a library of enzyme‐degradable polymers with desirable properties from the first reported step polyaddition of diamines, COS, and diacrylates. The polymers contain in‐chain ester and thiourethane groups, which can serve as lipase‐degradation and hydrogen‐bonding physical crosslinking points, respectively, resulting in possible biodegradability as well as upgraded mechanical and thermal properties. Also, the properties of the polymers are scalable due to the versatile method and the wide variety of monomers. We obtain 46 polymers with tunable performance covering high‐Tm crystalline plastics, thermoplastic elastomers, and amorphous plastics by regulating polymer structure. Additionally, the polymerization method is highly efficient, atom‐economical, quantitatively yield, metal‐ and even catalyst‐free. Overall, the polymers are promising green materials given their degradability, simple and modular synthesis, remarkable and tunable properties, and readily available monomers. [ABSTRACT FROM AUTHOR]

Single‐molecule force spectroscopy is a powerful tool for the quantitative investigation of the biophysics, polymer physics and mechanochemistry of individual polymer strands. One limitation of this technique is that the attachment between the tip of the atomic force microscope and the covalent or noncovalent analyte in a given pull is typically not strong enough to sustain the force at which the event of interest occurs, which makes the experiments time‐consuming and inhibits throughput. Here we report a polyelectrolyte handle for single‐molecule force spectroscopy that offers a combination of high (several hundred pN) attachment forces, good (~4%) success in obtaining a high‐force (>200 pN) attachment, a non‐fouling detachment process that allows for repetition, and specific attachment locations along the polymer analyte. [ABSTRACT FROM AUTHOR]

Researchers have been chasing plastics that can automatically and fully degrade into valuable products under natural conditions. Here, we develop a series of water‐degradable polymers from the first reported fast and selective cationic copolymerization of formaldehyde (B) with cyclic anhydrides (A). In addition to readily accessible monomers, the method is performed at industrially relevant temperatures (~100 °C), takes tens or even minutes, and uses common acid as the catalyst. Interestingly, such polymers possess tunable AB/ABB‐type repeating units, which are considered to be thermodynamic and kinetic products, respectively, resulting in low carbon content ([O] : [C] up to 1 : 1). Notably, the polymers can completely degrade to valuable diacids within 150 days in water at ambient temperature owing to the incorporation of carboxyl terminals and acid‐responsive acetal units. By washing with aqueous sodium carbonate, the polymers are relatively stable over several months. [ABSTRACT FROM AUTHOR]

Thermo-responsive diblock copolymer, poly(N-isopropylacrylamide)-block-poly(N-vinylisobutyramide) was synthesized via switchable reversible addition–fragmentation chain transfer (RAFT) polymerization and its thermal transition behavior was studied. Poly(N-vinylisobutyramide) (PNVIBA), a structural isomer of poly(N-isopropylacrylamide) (PNIPAM) shows a thermo-response character but with a higher lower critical solution temperature (LCST) than PNIPAM. The chain extension of the PNVIBA block from the PNIPAM block proceeded in a controlled manner with a switchable chain transfer reagent, methyl 2-[methyl(4-pyridinyl)carbamothioylthio]propionate. In an aqueous solution, the diblock copolymer shows a thermo-responsive behavior but with a single LCST close to the LCST of PNVIBA, indicating that the interaction between the PNIPAM segment and the PNVIBA segment leads to cooperative aggregation during the self-assembly induced phase separation of the diblock copolymer in solution. Above the LCST of the PNIPAM block, the polymer chains begin to collapse, forming small aggregates, but further aggregation stumbled due to the PNVIBA segment of the diblock copolymer. However, as the temperature approached the LCST of the PNVIBA block, larger aggregates composed of clusters of small aggregates formed, resulting in an opaque solution. [ABSTRACT FROM AUTHOR]

Plant cell wall researchers were asked their view on what the major unanswered questions are in their field. This article summarises the feedback that was received from them in five questions. In this issue you can find equivalent syntheses for researchers working on bacterial, unicellular parasite and fungal systems.

Synthetic chemistry has played a vital role in miscellaneous fields of human civilization over the past century. The synthetic stage yet remains time-consuming and labor-intensive. To overcome these limitations, automation has been introduced to transform synthetic chemistry, leading to the development of high-throughput methods for molecular discovery. Automated flow chemical synthesis (AFCS) has recently emerged as a promising candidate, offering improved efficiency, scalability, and sustainability over the well-known automated solid-phase peptide synthesis. To further advance AFCS, elements like artificial intelligence-based computer-aided structure design and synthesis planning, autonomously assembled compatible synthesis with enhanced automated process control, and autonomous optimization can be considered. This review focuses on recent advances in computer-aided automated flow chemical synthesis (CAAFCS) of polymers in living polymerization and iterative synthesis strategy. The current challenges and outlook are finally discussed for developing more powerful CAAFCS systems and expanding their applicability across numerous fields, potentially providing brand-new perspectives and guidelines for future developments in this field.

Organoboron reagents have garnered considerable attention due to their distinct properties. In recent years, boronic acids and boronate esters have been important intermediates for cross-coupling reactions and other functional group construction and are often used to synthesize small organic molecules, drugs, and bioactive substances. In this feature article, we encapsulate the strategy of harnessing the unique properties of organoboron reagents to overcome challenges encountered in conventional polymer synthesis. We delve into the synthesis of boron-containing monomers and polymer materials, unraveling the unique attributes of these newfound polymers while offering innovative insights into their application within recyclable or reprocessable materials. We develop organoboron-based photocatalysts, employing their inner-sphere electron transfer (ISET) mechanisms to initiate controlled radical polymerization. We utilize alkylborane to initiate controlled radical polymerization and further designed B-alkylcatecholboranes to prepare ultra-high molecular weight polymers. Notably, we also propose a liquid-phase synthesis method based on organoboron tags and apply it to the precise synthesis of sequence-controlled conjugated polymers. These advancements open up new frontiers in the realm of polymer science, and the versatility and potential of organoboron reagents in polymer synthesis continue to inspire exciting research endeavors. [ABSTRACT FROM AUTHOR]

Being an essential component of organic chemistry, named reactions are indispensable in organic synthesis. More and more named reactions have been devised to create unique polymer backbones, which has significantly accelerated the creation of new polymer materials. Yet, the university chemical knowledge system is deficient in relevant introductions. The purpose of this study is to incorporate the specified reactions within the teaching of polymer chemistry. These reactions are divided into six categories: transition metal-catalyzed coupling reactions, condensation reactions, pericyclic reactions, multi-component reactions, free radical reactions, and other reactions. This work methodically covers these six types of reactions, which are critical for polymer backbone synthesis, and presents the practice in teaching. It can assist students to learn polymer chemistry in conjunction with organic chemistry and provide some reference for students and teachers.

This paper presents a method for direct and alternating current electrospinning of polymeric solutions of three less common polyamides (nylons). Homopolyamide PA 8, heteropolyamide PA 6|9 and semi-aromatic amide (phthalamide) PA 6(3)T were dissolved in the formic acid and dichloromethane mixture, which have proved to be a suitable solvent for various other linear polyamides. The dependence of the viscosity, electrical conductivity, and spinnability via the direct (DC) and alternating current (AC) technology on the solution concentration was observed. Scanning electron microscope images of the prepared nanofibers were acquired and consequently analyzed for fiber defects, followed by measuring the fiber diameters. The differences in the nanofiber quality of DC layers and AC plumes were discussed. Finally, the optimal concentrations for the electrospinning of the examined solutions were determined. The communication follows our previous work and extends the number of electrospinnable polyamides, thus facilitating future research in this area.

The recovery of enriched Zn-68 is extremely important in the production of short-lived isotope (Ga-67) in the Cyclotron because of its high price. A high amount of Zn-68 is produced during the production of Ga-67 from its target (Zn-target) by a solvent extraction technique. In this investigation, we successfully prepared poly(vinyl alcohol-t-acrylamide), P(VA-t-AM) resin using the gamma radiolysis technique. The characterization of pristine PVA and synthesized P(VA-t-AM) was performed to confirm their structures. The produced polymer was tested for the elimination of Zn2+ ions from simulated liquid waste as produced during the production of the Ga-67. To get the highest uptake of Zn2+ ions on the polymer, various parameters such as solution pH, polymer weight, and contact time were applied. The loading Zn2+ ions were studied at optimum conditions of the Batch approach. Then, the retrieval of Zn2+ ions from the packed chromatographic column was tested using different parameters such as flow rates, bed depths, and initial concentration of Zn2+. The results indicated that the percentages of loaded Zn2+ ions on the packed column were 96.94% at the best operational conditions. Moreover, different eluents were applied to the retrieval of Zn2+ ions from the P(VA-t-AM) column, and the data confirmed that the retrieval percentage of Zn2+ ions from P(VA-t-AM) was 98.43% at the optimum. The reusability of the working polymer was examined for eight cycles. This paper recommended that the synthesized P(VA-t-AM) can be utilized for the retrieval of Zn2+ ions from the spent Zn-68 target in the Cyclotron. [ABSTRACT FROM AUTHOR]

Since the advent of supporting matrices for biological applications, many types of drugs have been administered via various forms of conventional drug delivery preparations, such as pills, solutions, creams, suppositories, injected gels and so on. Key parameters to all these systems for effective drug delivery are controlled release for sustained periods, targeted delivery, and enhancements of drug stability and efficacy, all of which can be manipulated by using polymers. Given the important impact of the structures of the polymers on these parameters, this mini‐review gives a simple introduction to the requirements of drug delivery systems and surveys the synthetic pathways to a key polymer in this field, namely poly(lactic acid). We also review the preparation of block copolymers that incorporate poly(lactic acid), to expand and further develop its properties for drug delivery systems. It is hoped that this short teacherly and introductory review will provide a basic stepping‐stone to more in‐depth reviews and papers and enable an easy access to this fast growing field. © 2023 Society of Industrial Chemistry. [ABSTRACT FROM AUTHOR]

In the field of non-oxide ceramics, the polymer-derived ceramic (PDC) approach appears to be very promising, especially for obtaining easily shaped and homogeneous materials in terms of structure and composition. However, in order to reach a suitable form during the process, it is often necessary to study the rheology of preceramic polymers while they are modified during polymerisation or crosslinking reactions. Given this need in the understanding of the real-time rheology of macromolecules during their synthesis, a rheometer coupled with both an infrared spectrometer and a Raman probe is described as a powerful tool for monitoring in situ synthesised polycarbosilanes. Indeed, this original device allows one to control the viscosity of a hyberbranched polycarbosilane from defined difunctional and tetrafunctional monomers. Meanwhile, it links this evolution to structural modifications in the macromolecular structure (molar masses, dispersity and conformation), based on SEC-MALS analyses, synchronised by the monomer conversion determined by using Raman and infrared spectroscopies, a common denominator of the aforementioned instrumental platform. [ABSTRACT FROM AUTHOR]

The facile synthesis of chemically recyclable polymers derived from sustainable feedstocks presents enormous challenges. Here, we develop a novel, modular, and efficient click reaction for connecting primary, secondary, or tertiary alcohols with activated alkenes via a bridge molecule of carbonyl sulfide (COS). The click reaction is successfully applied to synthesize a series of recyclable polymers by the step polyaddition of diols, diacrylates, and COS. Diols and diacrylates are common chemicals and can be produced from biorenewable sources, and COS is released as the industrial waste. In addition to sustainable monomers, the approach is atom‐economical, wide in scope, metal‐free, and performed under mild conditions, affording unprecedented polymers with nearly quantitative yields. The produced polymers also possess predesigned and widely tunable structure owing to the versatility of our method and the broad variety of monomers. The in‐chain thiocarbonate and ester polar groups can play as breakpoints, allowing these polymers to be easily recycled. Overall, the polymers have broad prospects for green materials given their facile synthesis, readily available feedstocks, desirable performance, and chemical recyclability. [ABSTRACT FROM AUTHOR]

A promising process to design non-isocyanate polyurethane (NIPU) foams has been developed. The transurethane polycondensation reaction between fatty biscarbamates, fatty diols, and diamines was used to synthesize a biobased aminotelechelic NIPU oligomer. The prepared oligomer (hard phase) was mixed with an amino-telechelic polydimethylsiloxane (PDMS, soft phase) and then reacted with a biosourced tri-epoxide molecule as crosslinking agent, in the presence of water/ethanol mixtures as physical blowing agents. The crosslinking reaction was followed by Fourier transform infrared spectroscopy (FTIR) and rheometry. The foams can be obtained in less than 2 hours at 95 °C. The prepared foams exhibited cell diameters ranging from 130 to 3090 μm, as well as densities ranging from 55 to 950 kg/m3. Their thermal stability thresholds were above 300 °C. They displayed glass transition temperature values ranging from –20 to –18 °C, and low values of the Young modulus ranging from 2.0·103 to 5.7·103 Pa. The hysteresis loss, the recovery time, and the firmness of these foams were dependent on the PDMS content and/or the morphological parameters. [ABSTRACT FROM AUTHOR]

A mathematical model and analysis of the continuous polymerization of partially neutralized acrylic acid (AA) in a continuous kneader reactor is presented here as an initial attempt to simulate the synthesis of a superabsorbent polymer. A detailed kinetic model has been used to describe the copolymerization of AA and sodium acrylate (NaA) in aqueous medium. This model is used to describe batch and continuous operations. The polymerization is initiated by a mixture of potassium persulphate (K2S2O8, KPS) and hydrogen peroxide (H2O2) as oxidizing agent and ascorbic acid (AsA) as reducing agent. A novel set of kinetic parameters has been estimated by fitting experimental data from different literature sources. The operation of a continuous kneader reactor modelled as a plug‐flow reactor with axial dispersion is theoretically investigated to predict temperature profile, total and individual monomer conversion, consumption of KPS, H2O2, and AsA, and polymer average molecular weights. The simulation results show the presence of a hot spot close to the reactor entrance that could be potentially severe during startup and could have a detrimental impact on polymer quality. This model is a first step in the direction of achieving optimal operating protocols and exploring improved polymerization reactor designs. [ABSTRACT FROM AUTHOR]

Several commercial silicas were used to support metallocene active centres, and the resulting precatalysts were used to study the impact of the pore size and pore size distribution of the support on the polymerization kinetics and resulting polymer properties. Pore volume distribution played a major role in the fragmentation of silica‐supported catalysts, where mesoporous silicas with a narrow distribution in the region obtained higher activities and faster fragmentation than silicas with a broad pore volume distribution. Therefore, it is shown that care must be taken when using standard information on particle porosity, as this quantity can be misleading. It appears that the minimum pore size, particularly on the particle surface, can be a very important parameter even if it does not impact the estimate of the porosity. [ABSTRACT FROM AUTHOR]

Highly biobased poly(butylene succinate-co-terephthalate) (PBST) with processing temperatures close to those of commodity polymers (160–180°C) and long-chain branched architectures (LCB) are synthesized by different strategies. Their rheological properties are investigated, in particular their melt strength properties. A two-step synthesis route is first proposed based on linear LCBs produced by polycondensation followed by reactive extrusion with an epoxy-based multifunctional agent Joncryl® at concentrations up to 2 wt%. A one-step synthesis strategy is also developed using glycerol as a branching agent, introduced at a low concentration (0.5 wt%) directly during the PBST polycondensation process. The molecular weights, LCB structures, and thermal properties are determined by triple detection size exclusion chromatography and differential scanning calorimetry. For PBSTs synthesized in two steps, gelation takes place simultaneously with the branching reactions. However, a concentration of Joncryl® close to 2 wt% is required to improve the melt strength properties, with strain hardening effects under elongation conditions. Interestingly, PBSTs synthesized by in-situ addition of glycerol show remarkable melt strength and a high melt stabilization process. Dynamic rheology investigations allow attributing these effects to statistical/homogeneous gel-free LCB architectures obtained during reactive extrusion without any additional post-processing. The effectiveness of approaches to easily improve the melt strength of highly biobased aliphatic-aromatic copolyesters (theoretical biobased content up to 85%) and to eliminate extrusion defects/instabilities in PBSTs is thus demonstrated, allowing the possibility of expanding the industrial application domains of these polymers in packaging and sustainable applications.

This paper presents a method for direct and alternating current electrospinning of polymeric solutions of three less common polyamides (nylons). Homopolyamide PA 8, heteropolyamide PA 6|9 and semi-aromatic amide (phthalamide) PA 6(3)T were dissolved in the formic acid and dichloromethane mixture, which have proved to be a suitable solvent for various other linear polyamides. The dependence of the viscosity, electrical conductivity, and spinnability via the direct (DC) and alternating current (AC) technology on the solution concentration was observed. Scanning electron microscope images of the prepared nanofibers were acquired and consequently analyzed for fiber defects, followed by measuring the fiber diameters. The differences in the nanofiber quality of DC layers and AC plumes were discussed. Finally, the optimal concentrations for the electrospinning of the examined solutions were determined. The communication follows our previous work and extends the number of electrospinnable polyamides, thus facilitating future research in this area. [ABSTRACT FROM AUTHOR]

The disconnection approach, a widely utilized method of design synthesis route, has played crucial roles in contemporary organic chemistry for decades. Here, we provide an introduction to the construction of polymer main chains. The implementation of the strategy hinges on determining where to disconnect based on the successful polymerization reaction in order to infer a suitable monomer. By investigating specific covalent bonds and structures in polymers, several specific linkers are highlighted to demonstrate how to design and synthesize polymer main chains using reverse thinking, thus inspiring those in polymer synthesis. [ABSTRACT FROM AUTHOR]

With the development of polymer science, more and more named reactions have been applied to synthesizing polymers. Introducing new reactions into polymer synthesis is undoubtedly an excellent expansion for monomer and polymer libraries. In this review, the named reactions employed in polymer-chain synthesis were divided into seven types: electrophilic reactions, nucleophilic reactions, transition metal-mediated cross-coupling reactions, free radical reactions, pericyclic reactions, multi-component reactions and rearrangement reactions. The discussion was mainly focused on the progress in the utilization of these named reactions in polymer synthesis, which could be a valuable reference for researchers in the polymer field. [ABSTRACT FROM AUTHOR]

In a brief review, the main trends in the modern development of the concept of controlled radical polymerization were considered and illustrated by specific examples. The prospects for applying the methodology of controlled synthesis of macromolecular structures, as well as for obtaining industrially significant and high-tech polymers, including precursors for the production of carbon fiber and other popular polymer materials and composites, were analyzed. Particular emphasis was placed on the use of photocatalysis and nature-like technologies in the controlled synthesis of polymers. [ABSTRACT FROM AUTHOR]

The green revolution in plastics should be accelerated due to growing sustainability concerns. Here, we develop a series of chemically recyclable polymers from the first reported cascade polymerization of H2O, COS, and diacrylates. In addition to abundant feedstocks, the method is efficient and air‐tolerant, uses common organic bases as catalysts, and yields polymers with high molecular weights under mild conditions. Such polymers, structurally like polyethylene with low‐density in‐chain polar groups, manifest impressive toughness and ductility comparable to high‐density polyethylene. The in‐chain ester group acts as a breaking point, enabling these polymers to undergo chemical recycling through two loops. The structures and properties of these polymers also have an immeasurably expanded range owing to the versatility of our method. The readily available raw materials, facile synthesis, and high performance make these polymers promising prospects as sustainable materials in practice. [ABSTRACT FROM AUTHOR]

Highly biobased poly(butylene succinate-co-terephthalate) (PBST) with processing temperatures close to those of commodity polymers (160-180°C) and long-chain branched architectures (LCB) are synthesized by different strategies. Their rheological properties are investigated, in particular their melt strength properties. A two-step synthesis route is first proposed based on linear LCBs produced by polycondensation followed by reactive extrusion with an epoxy-based multifunctional agent Joncryl® at concentrations up to 2 wt%. A one-step synthesis strategy is also developed using glycerol as a branching agent, introduced at a low concentration (0.5 wt%) directly during the PBST polycondensation process. The molecular weights, LCB structures, and thermal properties are determined by triple detection size exclusion chromatography and differential scanning calorimetry. For PBSTs synthesized in two steps, gelation takes place simultaneously with the branching reactions. However, a concentration of Joncryl® close to 2 wt% is required to improve the melt strength properties, with strain hardening effects under elongation conditions. Interestingly, PBSTs synthesized by in-situ addition of glycerol show remarkable melt strength and a high melt stabilization process. Dynamic rheology investigations allow attributing these effects to statistical/homogeneous gel-free LCB architectures obtained during reactive extrusion without any additional post-processing. The effectiveness of approaches to easily improve the melt strength of highly biobased aliphatic-aromatic copolyesters (theoretical biobased content up to 85%) and to eliminate extrusion defects/instabilities in PBSTs is thus demonstrated, allowing the possibility of expanding the industrial application domains of these polymers in packaging and sustainable applications. [ABSTRACT FROM AUTHOR]

Synthesizing polymers with precise sequence structures is of great significance but is still a great challenge in polymer science. The exploration of alkyne-based polymerizations recently has attracted considerable attention due to their great potential to construct polymers with diverse structures and versatile functions, especially those with precise sequence structures. In this review, we summarized recent advances in the preparation of sequence-controlled polymers by alkyne-base polymerizations. Representative examples of each method were selected to illustrate the essential construction principles and implementation approaches, which are expected to provide guidance for the development of sequence-controlled polymers. In addition, we also systematically introduce the diverse and appealing properties and applications of the obtained sequence-controlled polymers, hoping to promote the development of polymeric materials with more superior and innovative properties and applications.

In this paper, epoxy-acrylate structural adhesives tapes (SATs) were obtained from Bisphenol A-based liquid epoxy resin and epoxy acrylic resins (EARs). A new method of EARs preparation, i.e., the free radical bulk photopolymerization process (FRBP), was studied in detail. The influence of methacrylic monomers (methyl methacrylate, ethyl methacrylate, butyl methacrylate, lauryl methacrylate, (2-acetoacetoxy)ethyl methacrylate) and vinyl monomers (N-vinylpyrrolidone and styrene) on the FRBP process of base monomers (i.e., butyl acrylate, glycidyl methacrylate and 2-hydroxyethyl acrylate) was investigated. The kinetics of photopolymerization process was monitored by photo-differential scanning calorimetry method. The properties of the obtained EARs (viscosity and average molecular weights), as well as monomers conversion using 1H NMR, were determined. It was revealed that styrene significantly decreases the photopolymerization rate and increases the final monomers conversion (+27%). However, the resulting tetrapolymers BA-co-GMA-co-HEA-co-STY have low molecular weights and low polydispersity (2.2). Methacrylate monomers with shorter aliphatic chains (

[Display omitted] The aim of this study was the synthesis and evaluation of entirely S-protected thiolated hydroxyethylcellulose (HEC) with low and high viscosity, as well as thiolated poly-L-lysine (poly-L-Lys) used as dual-acting ionic as well as thiol-disulfide exchange mediated cross-linking hydrogel. Bis(mercaptosuccinic acid) was covalently attached to low and high viscous HECs via Fisher esterification, obtaining S-protected polymers. Poly-L-Lys-cysteine was synthesized via amidation of poly-L-Lys-HBr with cysteine (Cys). Thiolated polymers were examined in terms of cytotoxicity and rheological behavior of hydrogels containing these thiomers was evaluated with a cone-plate rheometer. Thiomers showed less cytotoxicity compared to the corresponding unmodified polymers. Rheological studies showed that cross-linking occurred between the two polymers via thiol-disulfide exchange reactions facilitated by the complementary charges. Employing poly-L-Lys-Cys in a concentration of either 0.5 or 5% (m/v) resulted in a 34.5-fold or 17.3-fold as well as a 53.6-fold or 29.6-fold improvement in dynamic viscosity within 5 min at 37 °C on S-protected thiolated low and high viscous HEC, compared to the corresponding unmodified HECs, respectively. By the combination of anionic S-protected thiolated polymers with a cationic thiolated polymer, dual-acting hydrogels exhibiting a time dependent increase in viscosity can be designed. [ABSTRACT FROM AUTHOR]

Tenofovir alafenamide (TAF) is an antiretroviral (ARV) drug that is used for the management and prevention of human immunodeficiency virus (HIV). The clinical availability of ARV delivery systems that provide long-lasting protection against HIV transmission is lacking. There is a dire need to formulate nanocarrier systems that can help in revolutionizing the way to fight against HIV/AIDS. Here, we aimed to synthesize a polymer using chitosan and polyethylene glycol (PEG) by the PEGylation of chitosan at the hydroxyl group. After successful modification and confirmation by FTIR, XRD, and SEM, TAF-loaded PEGylated chitosan nanoparticles were prepared and analyzed for their particle size, zeta potential, morphology, crystallinity, chemical interactions, entrapment efficacy, drug loading, in vitro drug release, and release kinetic modeling. The fabricated nanoparticles were found to be in a nanosized range (219.6 nm), with ~90% entrapment efficacy, ~14% drug loading, and a spherical uniform distribution. The FTIR analysis confirmed the successful synthesis of PEGylated chitosan and nanoparticles. The in vitro analysis showed ~60% of the drug was released from the PEGylated polymeric reservoir system within 48 h at pH 7.4. The drug release kinetics were depicted by the Korsmeyer–Peppas release model with thermodynamically nonspontaneous drug release. Conclusively, PEGylated chitosan has the potential to deliver TAF from a nanocarrier system, and in the future, cytotoxicity and in vivo studies can be performed to further authenticate the synthesized polymer. [ABSTRACT FROM AUTHOR]

In the field of non-oxide ceramics, the polymer-derived ceramic (PDC) approach appears to be very promising, especially for obtaining easily shaped and homogeneous materials in terms of structure and composition. However, in order to reach a suitable form during the process, it is often necessary to study the rheology of preceramic polymers while they are modified during polymerisation or crosslinking reactions. Given this need in the understanding of the real-time rheology of macromolecules during their synthesis, a rheometer coupled with both an infrared spectrometer and a Raman probe is described as a powerful tool for monitoring in situ synthesised polycarbosilanes. Indeed, this original device allows one to control the viscosity of a hyberbranched polycarbosilane from defined difunctional and tetrafunctional monomers. Meanwhile, it links this evolution to structural modifications in the macromolecular structure (molar masses, dispersity and conformation), based on SEC-MALS analyses, synchronised by the monomer conversion determined by using Raman and infrared spectroscopies, a common denominator of the aforementioned instrumental platform.

The gallol group, which contains three adjacent hydroxyl groups on a benzene, is a new bioinspired functional group for adhesives applications. The chemical structure of the gallol group possesses one more hydroxyl group on a benzene than the well-studied mussel-inspired adhesive group, catechol. Despite the small difference in chemical structure, gallol containing adhesive polymers show 7 times higher wet adhesion properties than the catechol containing adhesives under the identical experimental conditions. On account of the large enhancement of adhesion properties, the gallol containing adhesive polymers are gaining significant interest, and the related polymer science fields are expected to grow quickly. This review summarizes synthesis methods and diverse applications of gallol containing adhesive polymers. The goal of this review is to provide reasonable pathways for selecting and designing gallol containing polymer structures to maximize the adhesion properties for functional applications. [ABSTRACT FROM AUTHOR]

The selective sensing of gaseous target molecules is a challenge to analytical chemistry. Selectivity may be achieved in liquids by several different methods, but many of these are not suitable for gas-phase analysis. In this review, we will focus on molecular imprinting and its application in selective binding of volatile organic compounds and atmospheric pollutants in the gas phase. The vast majority of indexed publications describing molecularly imprinted polymers for gas sensors and vapour monitors have been analysed and categorised. Specific attention was then given to sensitivity, selectivity, and the challenges of imprinting these small volatile compounds. A distinction was made between porogen (solvent) imprinting and template imprinting for the discussion of different synthetic techniques, and the suitability of each to different applications. We conclude that porogen imprinting, synthesis in an excess of template, has great potential in gas capture technology and possibly in tandem with more typical template imprinting, but that the latter generally remains preferable for selective and sensitive detection of gaseous molecules. More generally, it is concluded that gas-phase applications of MIPs are an established science, capable of great selectivity and parts-per-trillion sensitivity. Improvements in the fields are likely to emerge by deviating from standards developed for MIP in liquids, but original methodologies generating exceptional results are already present in the literature. [ABSTRACT FROM AUTHOR]

In this study, modified natural rubber (MNR) was used as a solid adsorbent for carbon dioxide (CO2) capture. The chemical structure of the NR latex was modified by diallylamine. Moreover, the silica particles were modified by (3-aminopropyl)trimethoxysilane, N-[(3-trimethoxysilyl)propyl]ethylenediamine, or N-[(3-trimethoxysilyl)propyl]diethylenetriamine (mono-, di- and tri-amines) to improve the CO2 capture ability of the MNR. The CO2 adsorption capacity of the MNR foam composite was increased 3- to 5-fold after filling with unmodified or modified silica particles. The mechanism for CO2 adsorption of the MNR composite was a combination of physisorption and chemisorption. At 100 °C, the highest CO2 adsorption capacity of MNR foam composite (10.35 mg/g of adsorbent) was obtained by adding tri-amine-modified silica particles. Finally, the MNR foam composite material could be regenerated process for more than 20 CO2 adsorption cycles.

N-Sulfonyl-activated aziridines are known to undergo anionic-ring-opening polymerizations (AROP) to form polysulfonyllaziridines. However, the post-polymerization deprotection of the sulfonyl groups from polysulfonyllaziridines remains challenging. In this report, the polymerization of tert-butyl aziridine-1-carboxylate (BocAz) is reported. BocAz has an electron-withdrawing tert-butyloxycarbonyl (BOC) group on the aziridine nitrogen. The BOC group activates the aziridine for AROP and allows the synthesis of low-molecular-weight poly(BocAz) chains. A 13C NMR spectroscopic analysis of poly(BocAz) suggested that the polymer is linear. The attainable molecular weight of poly(BocAz) is limited by the poor solubility of poly(BocAz) in AROP-compatible solvents. The deprotection of poly(BocAz) using trifluoroacetic acid (TFA) cleanly produces linear polyethyleneimine. Overall, these results suggest that carbonyl groups, such as BOC, can play a larger role in the in the activation of aziridines in anionic polymerization and in the synthesis of polyimines. [ABSTRACT FROM AUTHOR]

The development of sustainable plastic materials will be flanked with conscious resource management, waste recovery frameworks, and social change. Nonetheless, developing strategies toward controlled polymer degradation remains a key challenge—whether as a failsafe mechanism for materials that escape the resource recovery cycle, or where distinct degradation pathways are required for specific applications such as in the biomedical realm. This perspective highlights recent trends, challenges, and future strategies on three levels: 1) On the materials level, by the incorporation of enzymes into polymer materials that catalyze polymer degradation under benign conditions; 2) On the domain level, crystalline segments of polymer materials are often inert, even to enzymatically catalyzed degradation. Gaining an understanding of the mode of interaction between enzymes and polymer chains is key to controlling degradation of all polymer morphologies within materials. Processive depolymerization mechanisms, where the enzyme binds polymer chain ends and depolymerizes along the chain are extremely promising for efficient polymer degradation; 3) On the molecular level, where polyesters exhibit enzymatic targets of ester bonds through their polymer backbone, poly(alkene)s c of all carbon backbones. To enable degradation of this most abundant class of polymers, strategies must be developed to incorporate enzymatic targets into the backbone. [ABSTRACT FROM AUTHOR]

Hierarchical porous polymer particles (HPPPs) from the assembly of polymer chains have attracted increasing interest because of their prospective applications in drug delivery and catalysis. This work utilized a blending strategy of polymer mixture in mixed solvents to fabricate HPPPs with adjustable pore structures. Firstly, using methacrylic acid (MAA) and methyl methacrylate (MMA) with a precise ratio, a copolymer solution of P(MMA‐MAA) was prepared in a mixed solvent of ethanol and water. Then, styrene (St) was added stepwise along with polymerization for achieving a translucent polymer mixture. Further, a quantitative amount of the polymer mixture and six‐fold volume of water were rapidly mixed with vortex oscillation. The HPPPs were formulated eventually by the assembly of hydrophilic P(MMA‐MAA) copolymers and hydrophobic PSt homopolymers, as well as micelles comprised of P(MMA‐MAA) copolymer and low‐polarity solvent. The size and number of nanopores were effectively regulated by the solvent polarity, polymerization temperature and monomer ratios. Moreover, the resultant HPPPs exhibited a hierarchical porous structure, having broad application in biomedical and environmental sciences. © 2022 Society of Industrial Chemistry. [ABSTRACT FROM AUTHOR]

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