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Polymer colloids are complex materials that have the potential to be used in a vast array of applications. One of the main reasons for their continued growth in commercial use is the water-based emulsion polymerization process through which they are generally synthesized. This technique is not only highly efficient from an industrial point of view but also extremely versatile and permits the large-scale production of colloidal particles with controllable properties. In this perspective, we seek to highlight the central challenges in the synthesis and use of polymer colloids, with respect to both existing and emerging applications. We first address the challenges in the current production and application of polymer colloids, with a particular focus on the transition toward sustainable feedstocks and reduced environmental impact in their primary commercial applications. Later, we highlight the features that allow novel polymer colloids to be designed and applied in emerging application areas. Finally, we present recent approaches that have used the unique colloidal nature in unconventional processing techniques. The authors would like to thank the financial support received from the Basque Government (IT-1525-22), from the Spanish Government (MINECO PID2021-123146OB-I00, MICINN PDC2021-121416-I00, and PID-117628RJ-I00)). This work was partially funded by the Michelin North America, Inc. and currently funded by the National Science Foundation (NSF) GOALI grant in partnership with Michelin (CMMI – 1762712). In addition, the Basque Government also financially supported this work (ELKARTEK/bmG22/ref: KK-2022/00008). The Basque Health Department (projects 2022333035, 2022333039, and 2022333031) and the University of the Basque Country (projects COLLAB22/05 and GIU21/033) are also acknowledged for their financial support.

This study describes the solvent-assisted organocatalysed depolymerisation of BPA-PC at low temperature for the selective formation of trimethylene carbonate. The key role of 1-methylimidazole as solvent and imidazole as catalyst is investigated.

As an alternative to the use of hazardous phosgene-based isocyanates for polyurethane preparation, non-isocyanate poly(hydroxy urethanes) (PHU) based on 5-membered cyclic carbonates have been developed. However, to date, most aromatic PHUs are oil-based or based on toxic precursors such as bisphenol-A. In this work, bio-based non-isocyanate poly(hydroxy urethanes) (PHUs) prepared from vanillin are reported for the first time. First, three different vanillin-derived bis-cyclic carbonates were synthesized. Subsequently, each monomer was reacted with two different bis-amines to yield six different PHUs, which were characterized in depth by 1H and 13C NMR spectroscopy, FTIR, SEC and DSC. PHUs based on vanillic acid were found to exhibit thermal properties superior to bisphenol A-based PHUs, with a Tg of around 66 °C. It is envisioned that vanillin-based PHUs could potentially be a safer alternative to harmful bisphenol A-based PHUs and provide a useful strategy for CO2 revalorization, especially considering that vanillin is an abundant byproduct of Kraft lignin production. The authors acknowledge financial support from the European Commission through SUSPOL-EJD 642671 project. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 101034379. The authors acknowledge grant TED2021-129852B-C22 funded by MCIN/AEI/10.13039/501100011033 and by the European Union NextGenerationEU/PRTR.

The inherent skeletal and thermal features to forge polymers by step-growth polymerization are conflicting with any depolymerization strategies via cascade back-biting reactions that necessitate adequate ceiling temperature, spacers, and functionalities to create cyclic compounds. Here, we report the edition of step-growth poly(carbonate-urea)s and poly(carbonate-amide)s that are depolymerized on demand into their native precursor or added-value offspring oxazolidinones, together with a hemiacetal cyclic carbonate. The unprotected in-chain secondary amide or urea functionalities of the polymers trigger their degradation via cascade ring-closing events upon a thermal switch (from 25 to 80 °C) in the presence of an organic base as a catalyst. Although most studies are realized in solution for understanding the deconstruction process, the polymers are also fully degraded in 2 h in neat conditions without any catalyst at 150 °C. At 80 °C, the organic base is required to accelerate the process. On the road to sustainability and circularity, we validate the concept by exploiting monomers designed from waste CO2 and upcycled commodity plastics. Ultimately, these polymers are selectively depolymerized from plastic mixtures composed of commodity poly(ethylene terephthalate) and polycaprolactone, offering new options for recycling plastic waste mixtures while delivering high-value-added chemicals.

Additive manufacturing (AM) of polymeric materials has allowed the manufacturing of complex structures for a wide range of applications. Among AM methods vat photopolymerization(VP) techniques are desired owing to their improved efficiency and printing resolution. Nevertheless, the major portion of resins available for VP are based on systems with limited or negligible recyclability. Here, we develop an approach that enables the printing of a resin that could be re-printed with retained properties and appearance. To that end, we take advantage of the potential of polythiourethane chemistry, which not only permits the “click” reaction between polythiols and polyisocyanates in the presence of organic bases, allowing a fast printing process, but also chemical recycling, reshaping and reparation of the printed structures, paving the way toward the development of truly sustainable recyclable photoprintable resins. We demonstrate that this closed-loop 3D printing process is feasible both in the macroscale and microscale via DLP or DLW respectively.

Graft copolymers between conducting PEDOT and biodegradable PCL were synthesized and investigated for 3D printing scaffolds for patterning of muscle cells.

The use of plastic waste to develop high added value materials, also known as upcycling, is a useful strategy towards the development of more sustainable materials. More specifically, the use of plastic waste as a feedstock for synthesising new materials for energy storage devices can not only provide a route to upgrading plastic waste but can also help in the search for sustainable materials. This perspective describes recent strategies for the use of plastic waste as a sustainable, cheap and abundant feedstock in the production of new materials for electrochemical energy storage devices such as lithium batteries, sodium batteries and supercapacitors. Two main strategies are described, the development of conducting carbons by combustion of plastic waste and the depolymerization of plastics into new chemicals and materials. In both cases, catalysis has been key to ensuring high efficiency and performance. Future opportunities and challenges are highlighted and hypotheses are made on how the use of plastic waste could enhance the circularity of current energy storage devices. NG acknowledges the funding from the European Union’s Horizon 2020 framework programme under the Marie Skłodowska-Curie agreement No. 101028682. CJ acknowledges the financial support from el Ministerio de ciencia e innovación from the Juan de la Cierva Program (FJC2020-045872-I). The funding from the European Union’s Horizon 2020 framework programme under the Marie Skłodowska-Curie agreement No. 101028975 and Ministerio de ciencia e innovación under PDC2021-121461-I00 project is acknowledged.

The importance of systematic and efficient recycling of all forms of plastic is no longer a matter for debate. Constituting the sixth most produced polymer family worldwide, polyurethanes, which are used in a broad variety of applications (buildings, electronics, adhesives, sealants, etc.), are particularly important to recycle. In this study, polyurethanes are selectively recycled to obtain high value-added molecules. It is demonstrated that depolymerization reactions performed with secondary amines selectively cleave the C–O bond of the urethane group, while primary amines unselectively break C–O and C–N bonds. The selective cleavage of C–O bonds, catalyzed by an acid:base mixture, led to the initial polyol and a functional diurea in several hours to a few minutes for both model polyurethanes and commercial polyurethane foams. Different secondary amines were employed as nucleophiles to synthesize a small library of diureas obtained in good to excellent yields. This study not only targets the recovery of the initial polyol but also aims to form new diureas which are useful building blocks for the polymerization of innovative materials. C.J. acknowledges the financial support from el Ministerio de ciencia e innovación from the Juan de la Cierva Program (FJC2020045872-I). The funding from the European Union’s Horizon 2020 framework programme under the Marie Skłodowska Curie agreement No. 101028975 and Ministerio de ciencia e innovación under PDC2021-121461-I00 project are acknowledged.

Over 30 million ton of poly(ethylene terephthalate) (PET) is produced each year and no more than 60% of all PET bottles are reclaimed for recycling due to material property deteriorations during the mechanical recycling process. Herein, a sustainable approach is proposed to produce redox-active nanoparticles via the chemical upcycling of poly(ethylene terephthalate) (PET) waste for application in energy storage. Redox-active nanoparticles of sizes lower than 100 nm were prepared by emulsion polymerization of a methacrylic-terephthalate monomer obtained by a simple methacrylate functionalization of the depolymerization product of PET (i.e., bis-hydroxy(2-ethyl) terephthalate, BHET). The initial cyclic voltammetry results of the depolymerization product of PET used as a model compound show a reversible redox process, when using a 0.1 M tetrabutylammonium hexafluorophosphate/dimethyl sulfoxide electrolyte system, with a standard redox potential of −2.12 V vs. Fc/Fc+. Finally, the cycling performance of terephthalate nanoparticles was investigated using a 0.1 M TBAPF6 solution in acetonitrile as electrolyte in a three-electrode cell. The terephthalate anode electrode displays good cycling stability and performance at high C-rate (i.e., ≥5C), delivering a stable specific discharge capacity of 32.8 mAh.g−1 at a C-rate of 30 C, with a capacity retention of 94% after 100 cycles. However, a large hysteresis between the specific discharge and charge capacities and capacity fading are observed at lower C-rate (i.e., ≤2C), suggesting some irreversibility of redox reactions associated with the terephthalate moiety, in particular related to the oxidation process. NC would like to thank the University of the Basque Country for funding through a specialization of research staff fellowship (ESPDOC 19/99). JD thanks WBI International and the Gobierno Vasco/Eusko Jaurlaritza (IT 999–16) for fundings. NG acknowledges the funding from the European Union’s Horizon 2020 framework programme under the Marie Skłodowska-Curie agreement No. 101028682.

Unformatted post-print version of the accepted article Solid-solid transitions in poly (hexamethylene carbonate) (PC6) and poly (octamethylene carbonate) (PC8), denoted δ to α transition, have been investigated, using self-nucleation and Successive Self-nucleation and Annealing (SSA) technique. The SSA protocol was performed in-situ for thermal (differential scanning calorimetry (DSC)), structural (Wide-angle X-ray Scattering (WAXS)), and conformational (Fourier-transformed Infrared Spectroscopy (FT-IR)) characterization. The final heating after SSA fractionation displayed an enhanced (compared to a standard second DSC heating scan) endothermic and unfractionated peak signal at low temperatures corresponding to the δ to α transition. The improved (i.e., higher enthalpy and temperature than in other crystallization conditions) δ to α transition signal is produced by annealing the thickest lamellae made up by α and β phase crystals after SSA treatment. As thicker lamellae are annealed, more significant changes are produced in the δ to α transition, demonstrating the transition dependence on crystal stability, thus, on the crystallization conditions. The ability of SSA to significantly enhance the observed solid-solid transitions makes it an ideal tool to detect and study this type of transitions. In-situ WAXS reveals that the δ to α transition corresponds to a change in the unit cell dimensions, evidenced by an increase in the d-spacing. This implies a more efficient chain packing in the crystal, for both samples, in the δ phase (lower d-spacing at low temperatures) than in the α phase (higher d-spacing at high temperatures). The chain packing differences are explained through in-situ FT-IR measurements that show the transition from ordered (δ phase) to disordered (α phase) methylene chain conformations. We would like to acknowledge financial support provided by the National Key R&D Program of China (2017YFE0117800) and the National Natural Science Foundation of China (51820105005, 21922308, and 52050410327). We also acknowledge financial support from the BIODEST project; this project has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie Grant Agreement No. 778092. This work has also received funding from MINECO through project MAT2017-83014-C2-1-P and from the Basque Government through grant IT1309-19. R.A.P.-C is supported by the China Postdoctoral Science Foundation (2020M670462). G.L. is grateful to the Youth Innovation Promotion Association of the Chinese Academy of Sciences (Y201908). We also thank the BSRF (beamline 1W2A) for providing beamtime.

The polyaddition between dicyclic carbonates and diamines leading to poly(hydroxy urethane)s (PHUs) has emerged as the preferred method for the synthesis of green, non-isocyanate polyurethanes. However, when proposed for use as structural adhesives, the long times for completion of aminolysis of the 5-membered cyclic carbonates under ambient conditions force the use of complementary chemistries to accelerate the curing process. In this work, a system that combines an amino-terminated PHU (NH2-PHU-NH2), an epoxy resin, and a thiol compound was employed to develop high-shear strength PHU-epoxy hybrid adhesives able to cure at room temperature in short times. A NH2-PHU-NH2 prepolymer synthesized by using a sub-stoichiometric quantity of dicyclic carbonates was mixed with a bisphenol A-based epoxy resin for the preparation of the structural adhesive. While this adhesive showed good lap-shear strength and shear resistance under static load and temperature, the curing process was slow. In order to speed up the curing process, a thiol (trimethylolpropane tris(3-mercapto propionate)) was added and its impact on the curing process as well as on the adhesive properties was evaluated. The trifunctional thiol additive allowed for faster curing in the presence of the 1,1,3,3-tetramethylguanidine basic catalyst. Moreover, a combination of NH2-PHU-NH2 and the thiol as curing agents for the epoxy resin resulted in adhesives with superior toughness, without any deterioration of the ultimate lap-shear strength or shear resistance under load and temperature, making these adhesives suitable for high-demand applications in the automotive industry. The authors would like to acknowledge the technical and human support provided by SGIker (UPV/EHU and ERDF, EU) . A.G.-L. would like to acknowledge the University of the Basque Country for the predoctoral fellowship received to carry out this work and Dr. Nora Aranburu for the help with the lap-shear measurements. ORIBAY Group Automotive also wants to acknowledge HAZITEK program for the financial support of the project no ZL-2019/00193. The authors want to acknowledge the financial support of the EU through the project NIPU-EJD 9555700. C.D. is FNRS Research Director and would like to thank FNRS for financial support.

Plastic recycling is doubtless a realistic solution for the disposal of plastics and biocatalysis is a key enabling technology for that aim. However, despite advances done in the development of new plastic degrading enzymes, the molecular mechanisms that govern their catalytic performance are poorly understood hampering the engineering of efficient enzyme technology. In this work, we study the hydrolysis of PET oligomers catalysed by the highly promiscuous lipase B from Candida antarctica (CALB) through QM/MM molecular dynamics simulations supported by experimental Michaelis-Menten kinetics. The computational studies reveal the unknown role of the pH on the CALB regioselectivity toward the hydrolysis of bis-(hydroxyethyl) terephthalate (BHET). We exploited this insight to perform pH-controlled biotransformation that selectively hydrolyses BHET to either its corresponding diacid or monoesters using both soluble and immobilized CALB. The discoveries presented here have been exploited for the valorisation of BHET resulting from the organocatalytic depolymerization of PET.

Unformatted post-print version of the accepted article Poly (hexamethylene carbonate) (PC6) and poly (octamethylene carbonate) (PC8) were studied under different crystallization conditions. Using differential scanning calorimetry (DSC), a new solid-solid transition, denoted α to δ transition, was detected at low temperatures (

Polyurethane (PU) adhesives and coatings are widely used to fabricate high-quality materials due to their excellent properties and their versatile nature, which stems from the wide range of commercially available polyisocyanate and polyol precursors. This polymer family has traditionally been used in a wide range of adhesive applications including the bonding of footwear soles, bonding of wood (flooring) to concrete (subflooring), in the automotive industry for adhering different car parts, and in rotor blades, in which large surfaces are required to be adhered. Moreover, PUs are also frequently applied as coatings/paints for automotive finishes and can be applied over a wide range of substrates such as wood, metal, plastic, and textiles. One of the major drawbacks of this polymer family lies in the use of toxic isocyanate-based starting materials. In the context of the REACH regulation, which places restrictions on the use of substances containing free isocyanates, it is now urgent to find greener routes to PUs. While non-isocyanate polyurethanes (NIPUs) based on the polyaddition of poly(cyclic carbonate)s to polyamines have emerged in the past decade as greener alternatives to conventional PUs, their industrial implementation is at an early stage of development. In this review article, recent advances in the application of NIPUs in the field of adhesives and coatings are summarized. The article also draws attention to the opportunities and challenges of implementing NIPUs at the industrial scale.

UV light-induced polymerization is one of the most efficient methods to produce pressure-sensitive adhesives (PSAs) in lamination processes, as it is simple and easily scalable. Among the wide variety of monomers used in light-induced polymerizations, acrylates and/or methacrylates are typically used as the main components due to their versatility and their high reactivity. However, as radical polymerization is not tolerant to the presence of oxygen, O2 inhibitors must be added, which increases the final cost of the laminate adhesive. In this work, we exploit the oxygen insensitivity of thiol-click reactions and evaluate their potential for use in fast and inexpensive UV curable resins for lamination processes. After some preliminary investigations that demonstrate the need for a radical inhibitor to extend the shelf life of the noncured resin, we confirm the insensitivity of this reaction to the presence of oxygen. After evaluating the effect of several parameters, including the effect of thiol functionality, vinyl ester structure, and the addition of an acrylate, we demonstrate the design of a formulation with competitive adhesive performance compared to conventional photopolymerized acrylic PSAs. Materials with relatively high gel content (66%), intermediate crosslinking (swelling degree 391%), and low Tg were obtained using a bifunctional thiol, an aliphatic vinyl monomer, and a polyurethane-based diacrylate. This formulation has good potential for the replacement of acrylate-based adhesives because it is capable of polymerization in short times and in the presence of oxygen and possesses fast adhesion to the substrate and a very good adhesive/cohesive ratio. UV light-induced polymerization is one of the most efficient methods to produce pressure-sensitive adhesives in lamination processes, as it is simple and easily scalable. Acrylates and/or methacrylates are typically used as the main components, however, O2 inhibitors are needed, which increases the final cost. In this work, we exploit the oxygen insensitivity of thiol-click reactions, evaluate their potential for use in fast and inexpensive UV curable resins, and demonstrate the design of a formulation with competitive adhesive performance compared to conventional acrylic PSAs.

Organocatalysis has evolved into an effective complement to metal- or enzyme-based catalysis in polymerization, polymer functionalization, and depolymerization. The ease of removal and greater sustainability of organocatalysts relative to transition-metal-based ones has spurred development in specialty applications, e.g., medical devices, drug delivery, optoelectronics. Despite this, the use of organocatalysis and other organomediated reactions in polymer chemistry is still rapidly developing, and we envisage their rapidly growing application in nascent areas such as controlled radical polymerization, additive manufacturing, and chemical recycling in the coming years. In this Review, we describe ten trending areas where we anticipate paradigm shifts resulting from novel organocatalysts and other transition-metal-free conditions. We highlight opportunities and challenges and detail how new discoveries could lead to previously inaccessible functional materials and a potentially circular plastics economy.

Functionalized cyclic carbonates are attractive monomers for the synthesis of innovative polycarbonates or polyurethanes for various applications. Even though their synthesis has been intensively investigated, doing so in a sustainable and efficient manner remains a challenge. Herein, we propose an organocatalytic procedure based on the depolymerization of a commodity polymer, bisphenol A based polycarbonate (BPA-PC). Different carbonate-containing heterocycles are obtained in good to excellent yields employing BPA-PC as a sustainable and inexpensive source of carbonate, including functionalized six-membered cyclic carbonates.

Chemical recycling of plastic waste represents a greener alternative to landfill and incineration, and potentially offers a solution to the environmental consequences of increased plastic waste. Most plastics that are widely used today are designed for durability, hence currently available depolymerisation methods typically require harsh conditions and when applied to blended and mixed plastic feeds generate a mixture of products. Herein, we demonstrate that the energetic differences for the glycolysis of BPA-PC and PET in the presence of a protic ionic salt TBD:MSA catalyst enables the selective and sequential depolymerisation of these two commonly employed polymers. Employing the same procedure, functionalised cyclic carbonates can be obtained from both mixed plastic wastes and industrial polymer blend. This methodology demonstrates that the concept of catalytic depolymerisation offers great potential for selective polymer recycling and also presents plastic waste as a "greener" alternative feedstock for the synthesis of high added value molecules.

Polymers that are biocompatible and degradable are desired for tissue engineering approaches in the treatment of vascular diseases, especially for those involving small-diameter blood vessels. Herein, we report the compatibility of a newly developed glycerol-based aliphatic polycarbonate possessing simple methoxy side groups, named poly(5-methoxy-1,3-dioxan-2-one) (PMDO), with blood cells and plasma proteins as well as its susceptibility to hydrolysis. As a consequence of the organocatalytic ring-opening polymerization (ROP) of a methoxy-functionalized cyclic carbonate derived from glycerol, PMDO with a sufficiently high molecular weight (Mn 14 kg/mol) and a narrow distribution (DM 1.12) was obtained for evaluation as a bulk biomaterial. This study demonstrates for the first time the organocatalytic ROP of a glycerol-based cyclic carbonate in a controlled manner. Compared with the clinically applied aliphatic polycarbonate poly(trimethylene carbonate) (PTMC), PMDO inhibits platelet adhesion by 33% and denaturation of fibrinogen by 23%. Although the wettability of PMDO based on water contact angle was almost comparable to those of PTMC and poly(ethylene terephthalate), the reason for the inhibited platelet adhesion and protein denaturation appeared to be related to the presence of specific hydrated water formed in the hydrated polymer. The improved hydration of PMDO also enhanced the susceptibility to hydrolysis, with PMDO demonstrating a slightly higher hydrolytic property than PTMC. This simple glycerol-based aliphatic polycarbonate has the following benefits: bio-based characteristics of glycerol and improved blood compatibility and hydrolytic biodegradability stemming from moderate hydration of the methoxy side groups.

Photoinduced polymerization is a useful tool in many industrial applications such as coatings, adhesives and 3D printing. However, the use of light to promote polymerization has been almost exclusively used for radical photopolymerization, thus excluding a wide variety of monomers. In this context, the use of light irradiation to trigger other polymerizations to produce degradable polymers has scarcely been studied. Herein, we investigate the use of six novel photoacid generators based on anthrone and anthraquinone chromophores capable of producing triflic, para-toluensulfonic and methanesulfonic acids upon 365 nm LED light irradiation to trigger the ROP of cyclic esters. The efficiency of the catalyst is shown to be strongly related to the chromophore and the sulfonate substituent. After characterizing the photodissociation process using UV-Visible and NMR spectroscopy, DFT calculations were carried out in order to understand the photodissociation mechanism. Their use as effective catalysts for the cationic ring-opening polymerization of e-Cl is confirmed by 1H NMR and SEC analysis either in solution or in bulk, obtaining fast polymerization rates at 100 °C. This catalyst family shows the ability to form polyester based coatings using light, expanding the number of coatings that may be prepared by photopolymerization processes.

We report the design, synthesis, and evaluation of biodegradable amphiphilic poly(ethylene glycol)-b-polycarbonate-based diblock copolymers containing pendant persistent organic radicals (e.g., PROXYL). These paramagnetic radical-functionalized polymers self-assemble into micellar nanoparticles in aqueous media, which preferentially accumulate in tumor tissue via the enhanced permeability and retention (EPR) effect. Through T1 relaxation NMR studies, as well as magnetic resonance imaging (MRI) studies on mice, we show that these nanomaterials are effective as metal-free, biodegradable MRI contrast agents. We also demonstrate anticancer drugs can be readily loaded into the nanoparticles, conferring therapeutic delivery properties in addition to their imaging properties making these materials potential theranostic agents in the treatment of cancer.

Organocatalysis provides a powerful alternative in many polymerization reactions and nowadays has become a valuable tool for polymer chemists. The key reason for transitioning to organocatalysts is not only their ability to be effectively removed from resultant products, but also, their potential to exquisitely control the catalytic activity and selectivity of the polymerization processes. While organocatalysis has been largely implemented in research laboratories, its use in industrial bulk polymerization processes is still scarce. This is mostly due to the poor thermal stability of organocatalysts at temperatures (150-250 °C) usually employed for industrial polymerizations. In this Viewpoint, we highlight the recent advances of the use of acid-base ionic mixtures in high temperatures bulk polymerization reactions. First, we will focus on the synthesis, characterization, difunctional catalytic properties, and thermal stability of these acid-base mixtures. Afterward, we will emphasize the recent literature describing their use in chain growth and step-growth polymerizations. Moreover, the highlight will also draw attention to recent efforts in the use of these acid-base mixtures in polymer recycling by means of depolymerization.

We have developed a general method for the functionalization of cyclic carbonate monomers having a pentafluorophenyl ester substituent at the 5-position (MTC-OC

The use of organocatalysts for the polymerization of ethylene brassylate, a commercially available, cheap, and renewable macro(di)lactone is reported for the first time. Ethylene brassylate was polymerized by ring-opening polymerization under bulk and solution conditions at 80 °C. Polymerizations were carried out in the presence of several organic catalysts, such as dodecylbenzenesulfonic acid (DBSA), diphenyl phosphate (DPP), p-toluenesulfonic acid (PTSA) and bases, 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), 1,2,3-tricyclohexylguanidine (TCHG), and 1,2,3-triisopropylguanidine (TIPG), using benzyl alcohol as initiator. Results agreed with a ring opening polymerization process in which the rate of polymerization was accelerated by the catalysts presence in the order of TBD > PTSA > DBSA > DPP > TIPG > TCHG. Complementary computational studies supported the experimental results. The obtained poly(ethylene brassylate) aliphatic polyesters were characterized by NMR, SEC, MALDI-TOF, DSC, and TGA. They showed m...

Organic acids were explored as a means to expand the library of cyclic carbonate monomers capable of undergoing controlled ring-opening polymerization. Various nitrogenous bases have proven incredibly adept at polymerizing cyclic carbonates; however, their use has largely precluded monomers with an acidic proton. Molecular modeling of acid catalysis provided new mechanistic insight, wherein a bifunctional activation pathway was calculated. Depending on acid structure, modeling experiments showed both monomer carbonyls and propagating hydroxyl groups undergo hydrogen bonding activation. The dual activation mechanism suggests acid strength, as well as conjugate base effects, play vital roles in catalyzing cyclic carbonate polymerizations. Moreover, the use of acid catalysis was shown to be compatible with amide-containing monomers while promoting controlled polymerizations.

Herein, we demonstrate 3D printing of an elastomeric imidazolium polyamide-ionene which exhibits intrinsic shape-memory (SM) and self-healing (SH) character, reporting optimized printing conditions...

Unformatted postprint Additive manufacturing (AM) is energizing the fields of chemistry and materials science to develop new inks for new applications within fields such as aerospace, robotics, and healthcare. AM enables the fabrication of innumerable 3D geometries that cannot be easily produced by other means. In spite of the great promise of AM as an advanced form of future manufacturing, there are still fundamental challenges with respect to sustainability that need to be addressed. Some of the material needs for AM include sustainable sources of printing inks, resins, and filaments, as well as pathways for polymer recycling, upcycling, and chemical circularity. Furthermore, the combination of bio-sourced and biodegradable polymers with additive manufacturing could enable the fabrication of objects that can be recycled back into feedstock or degraded into non-toxic products after they have served their function. Herein, we review the recent literature on the design and chemistry of the polymers to that enable sustainability within the field of AM, with a particular focus on biodegradable and bio-sourced polymers. We also discuss some of the sustainability-related applications that have emerged as a result of AM technologies. E.S.-R. thanks the European funding by the Marie Sklodowska-Curie Individual Fellowships (MSCA-IF-GF) 841879-4D Biogel. H.S. and C.J. thank MINECO for funding through MAT2017-83373-R. A.N. thanks the National Science Foundation for support (1752972).

Imidazolium-based ionenes are known to be high-performance materials for a great variety of applications. The preparation of these polymers requires the use of bis-imidazole starting monomers, which are commonly prepared by using toxic chloride reagents. In this study, bis-imidazole monomers are synthesized by organocatalytic chemical recycling of discarded plastics through chemical depolymerization. By using poly(ethylene terephthalate) and bisphenol A polycarbonate as starting materials, different monomers containing amide or urea functionalities are prepared to produce high-molecular-weight ionic polymers. These novel ionenes show excellent elastomeric and self-healing behavior, serving as a promising means to expand the exploration of plastic wastes as a source of new materials.

In the current climate of growing environmental concerns, especially taking into consideration the finite nature of global petroleum resources, biobased polymers are synthetic targets of great inte...