Showing papers in "Macromolecular Chemistry and Physics in 2022"

Fully Biobased Vitrimers: Future Direction Towards Sustainable Cross‐Linked Polymers

Abstract: Improving the sustainability of polymer networks is a crucial challenge in polymer science due to their important role in industry. Their traditional syntheses conflict with several principles of green chemistry as the employed monomers are petroleum-based, their production involves the use of toxic reagents, and their permanently cross-linked structures impede their chemical recycling and reshaping. The development of vitrimers represents a unique solution to address the issue of polymer network end-of-life by enabling reprocessability while maintaining good thermomechanical properties and solvent resistance. Although over the last decades biomass has proved to be an excellent feedstock for the production of permanently cross-linked polymers, the field of biobased vitrimers is still in its infancy. In this review, a comprehensive overview of vitrimers synthesized from biobased monomers is presented. The emphasis is set on the compatibility of the biomass structure with the nature of the dynamic covalent chemistry, as well as the sustainability of the synthetic approaches. Implementing renewable feedstocks and recyclability in the production of polymer networks paves the way for the development of the next generation of sustainable materials.

Sunlight Induced Polymerization photoinitiated by Novel Push‐pull dyes: indane‐1,3‐dione, 1H‐cyclopenta[b]Naphthalene‐1,3(2H)‐dione and 4‐dimethoxyphenyl‐1‐allylidene Derivatives

Abstract: The free radical polymerization of acrylates photo-initiated by push–pull dye-based photoinitiating systems (PISs) is widely investigated in previous works. As a supplementary investigation on push–pull dyes, here in this article, 25 push–pull structures comprising electron acceptors derived from indane-1,3-dione and 1H-cyclopenta[b]naphthalene-1,3(2H)-dione (series 1) and 4-dimethoxyphenyl-1-allylidene moieties (series 2) and various electron donors are synthesized and examined as innovative structures for photoinitiation. Among the two series of dyes examined in this work and by monitoring the polymerization processes by RT-FTIR measurements, four dyes are determined as exhibiting excellent photoinitiation performances and these dyes are selected to perform further studies concerning the chemical mechanisms occurring inside the three-component PISs, for example, steady state photolysis, fluorescence quenching measurements, and cyclic voltammetry. Markedly, their reactivity is also proved by photoinitiation performance upon sunlight. These results prompt us to develop high performance push–pull dyes as photosensitizers and sunlight can be used as a mild and ecofriendly light source, which can advantageously replace LEDs for the free radical photopolymerization in the future. Finally, the formation of 3D patterns with an excellent gradient of resolution is successfully achieved by the direct laser write (DLW) with/without silica fillers.

Nontraditional Organic/Polymeric Luminogens with Red‐Shifted Fluorescence Emissions

Abstract: Nontraditional organic/polymeric luminogens, which do not contain any conventional chromophores like large π-conjugated benzene rings and/or heterocycles, have attracted rapidly growing attention owing to their importance in the fundamental understanding of photoluminescence mechanisms and potential practical applications. However, compared to traditional luminogens, most nontraditional luminogens (NTLs) emit fluorescence in the blue region, and only very limited NTLs with green, yellow, and red emissions have been reported. It is of great scientific and practical importance to develop NTLs with red-shifted emissions and understand their mechanisms. This review first provides a brief overview of the types of NTLs based on heteroatoms in them, the luminescence mechanism and luminescent characteristics of NTLs, then summarizes recent progress in NTLs with red-shifted emissions and the main strategies employed, i.e., introducing multiple nonconventional chromophores, introducing intra-/intermolecular interactions to rigidify clusters, and introducing electron-giving/withdrawing groups into molecules to lower the gap between the HOMO–LUMO energy levels. This review also provides the perspectives and outlook on future development of NTLs with red-shifted emissions.

A Review on Lignin‐Based Phenolic Resin Adhesive

Abstract: Replacing petroleum-based chemicals with biomass-based alternatives is becoming more and more important for the development of a low-carbon economy around the world. The latest life cycle assessment displayed that partially replacing phenol with biobased lignin in the process of synthesizing phenolic resin adhesives used in wood panels industry can remarkably reduce carbon emissions and negative environmental impact. The macromolecular structure of lignin is similar to that of phenolic resin and the basic structure unit is similar to that of the phenol, thus endowing it with the potential to substitute phenol and reduce the release of formaldehyde in the preparation process of phenolic resin. Importantly, the lignin-based adhesive exhibits improved performance and reduced cost compared with the petroleum-based adhesive due to the reduced adding amount of petroleum-based volatile components. However, the intrinsic large steric hindrance, structural heterogeneity, and low activity of the natural lignin limit its further application in the adhesive. Many researchers have developed the activation methods such as physical modification, chemical modification, and biological modification to overcome these issues. The different modification of the lignin and their application in the adhesive area are mainly summarized here. Besides, the modification methods and the curing mechanism are also discussed.

A Water Soluble, Low Migration and Visible Light Photoinitiator by Thioxanthone‐Functionalization of Poly(ethylene glycol)‐Containing Poly( β ‐amino ester)

Abstract: A novel photoinitiator (PI) is described here for low ecological impact, p(PEGDA575-TX): It is water soluble, polymerizable, thioxanthone (TX) functional, and is a one-component poly(ethylene glycol)-based poly(β-amino ester). The PI is synthesized in one step via classical aza-Michael addition reaction between poly(ethylene glycol) diacrylate (Mn = 575 D) and amine functionalized TX (2-(2-aminoethoxy)-9H-thioxanthen-9-one). It absorbs at ≈ 404 nm (ε = 14 000–44 309) in water and can photodecompose with or without additives such as ethyl 4-(dimethylamino)benzoate (EDB) and bis-(4-tert-butylphenyl)-iodonium hexafluorophosphate (Iod). Although it is an effective one-component visible light PI for free radical polymerization of di- and tri(meth)acrylates, EDB or Iod will be favorable for synergistic effect. p(PEGDA575-TX) has higher initiating reactivity, reducing ability of oxygen inhibition and migration stability compared to TX, which make it environmental friendly.

Evaluating the Effect of Chemical Digestion Treatments on Polystyrene Microplastics: Recommended Updates to Chemical Digestion Protocols

Abstract: Establishing the toxicity and exposure consequences of microplastics (MPs) on marine organisms relies on the nondestructive isolation of plastics from biological matrices. MPs are commonly extracted from these matrices by chemical digestion using alkali (e.g., potassium hydroxide (KOH) and sodium hydroxide (NaOH)), oxidative (e.g., hydrogen peroxide (H2O2)) and/or acidic (e.g., nitric acid (HNO3)) reagents. Although these digestion conditions can be highly effective for MP extraction, they can also react with the plastics. This can attribute an inaccurate representation of plastic contamination by altering MP visual characteristics (size, shape, color), thereby impeding identification and potentially returning erroneous numbers of ingested particles. In this study, the degradative impacts are assessed of the routinely applied digestion reagents (i) KOH, (ii) NaOH, (iii) H2O2, and (iv) HNO3 on polystyrene (PS) based MPs sized between 200 µm and 5 mm. Degradation of the PS MPs is evaluated using FT-IR, gel permeation chromatography, NMR, photoluminescence spectroscopy, and microscopy. These studies reveal HNO3 to be the most destructive for PS MPs, while the alkali and oxidative reagents result in negligible changes in plastic properties. These results are recommended to be used as a guideline to update current protocols to ensure the nondestructive treatment of MPs.

The Frontier of Plastics Recycling: Rethinking Waste as a Resource for High‐Value Applications

Abstract: Following the circular economy hierarchy of reduce and reuse, recycling is the third layer to close the loops for materials and decouple their value from consumption. Polymeric materials (“plastics”) are in principle well suited for recycling, as they can be reprocessed with relatively low energy input as a material, cleaved back into their monomers or converted back to feedstock. Today, these approaches still fall short in quantitatively diverting waste towards reuse. This perspective describes the industry challenges for recycling back into high value applications of polymers, and the portfolio of existing and emerging technology solutions. Sustainable design of products and polymers, recycling technologies, appropriate business models, and enabling technologies converge at the frontier of plastics recycling, for a transformation of the industry towards circularity and greenhouse gas emission neutrality.

Recent Progress in Preparation and Application of Fibers using Microfluidic Spinning Technology

Abstract: Microscale fibrous materials with high surface areas and ordered structures have attracted widespread attention recently. Microfluidic spinning technology that can effectively control the sizes, structures, and material compositions of fibers has emerged as a robust approach for the fabrication of high-performance fibers. In this review, the microfluidic spinning technology used to prepare fibrous materials in terms of preparation principles and geometric configurations is presented. Additionally, several applications of fibers spun by microfluidic spinning technology, especially in tissue engineering, drug release, flexible electronics, water collection, and surgical suturing are introduced. Finally, the current challenges and perspectives of this technology are discussed.

Hybrid – Non‐Isocyanate Polyurethanes (H‐NIPUs): A pathway Towards a Broad Range of Novel Materials

Abstract: The increasing demand for using less toxic and dangerous products has fostered the development of nonisocyanate polyurethanes (NIPUs). Despite several years of progress within the search for these novel materials, they are still facing difficulties to reach the market. This may be due to the low mechanical properties obtained, which can be explained by the difficult access to high molar masses polymers. The combination of NIPUs with other types of polymers, thus forming polymer–polymer hybrid-NIPUs (so called H-NIPUs) can be an interesting alternative for the valorization of NIPUs though. This review describes the latest advancements in the developments of H-NIPUs, with a specific focus on the combination with epoxy, polyacrylic, and silicium-containing polymers. Finally, the emerging field of combining NIPUs with biopolymers is discussed. A specific focus on the synthetic challenges is provided, as well as their resulting influence onto the final material properties, thus showing how the synergistic combination of NIPUs with other polymers can be a promising pathway toward the formation of novel materials.

Silyl glyoximides: Toward a New Class of Visible Light Photoinitiators

Abstract: Many academic and industrial works are carried out for the search of new classes of visible light photoinitiators. In the last decade, new Type I photoinitiator generating silyl, germyl, or stannyl radicals is elegantly reported; the chemical mechanisms being often associated with the cleavage of the C(═O)Si, C(═O)Ge, or C(═O)Sn bonds. In this context, silyl glyoxylates are also reported as dual Type I and Type II photoinitiators. Silyl glyoximides are proposed here as new near-UV and blue light sensitive photoinitiators. The synthesis of such compounds as well as their light absorption properties is discussed. Their photochemical properties are studied through steady state photolysis experiments and molecular modeling data (i.e., through the calculations of the frontier orbitals, CC bond dissociation energies and triplet state energy levels). To finish, their photoinitiating ability upon near-UV or blue light emitting diode light is examined in a benchmark methacrylate monomer blend (BisGMA/TEGDMA). Markedly, a Type I photoinitiator behavior is highlighted but better initiating properties are found in multicomponent systems in combination with iodonium salt and amine.

Design for Recycling Strategies Based on the Life Cycle Assessment and End of Life Options of Plastics in a Circular Economy

Abstract: The plastic economy, despite offering unique properties in fulfilling the functions of products in different industrial sectors over decades, has so far been mainly linear, that is, “take-make and dispose” with only a small fraction of plastics being recycled worldwide. With ever-increasing circular economy initiatives and the urge to conserve resources and prevent plastic pollution from affecting ecosystems, more emphasis on the resource recovery of plastic products after its use has been made over the last few years. It is necessary for manufacturers to understand the value chain as early as the design phase while manufacturing and distributing plastic products across the world. The current study provides an overview of the status quo of plastic waste management and analyzes the Life Cycle Assessment (LCA) studies of different End-of-Life (EoL) options for plastics. Based on the LCA studies, a preliminary, country-specific Circular Footprint (CF) is calculated and Design for Recycling (DfR) strategies are identified. Results show that the environmental impacts of different EoL options differ significantly for different plastics. The CF highlights the lack of data regarding the composition and recovery of plastics in different countries thus showing the necessity to consider the whole lifecycle when quantifying the environmental impacts of plastics.

Design of Antimicrobial Polymers

Abstract: Antibiotic resistance has become a critical issue, alarming the healthcare and agriculture sectors worldwide. Thanks to rapid advancements in polymer science, antimicrobial polymers (AMPs) have been developed as a mimic version of host-defense peptides (a part of natural immune systems of multicellular organisms) to mitigate antibiotic resistance. By exploiting advanced polymerization techniques, polymer structures are easily manipulated in a well-defined controlled manner, enabling precise and accurate evaluation of the structure–activity relationship. Recent years have witnessed the blossoming of antimicrobial polymer development. This review provides comprehensive insight into antimicrobial polymers from concept to structure design, to biofunction control. Along with the optimization of intrinsic factors, including compositional and topological features, external factors like induced conformation upon exposure to specific targeting pathogens should be considered in AMP design and optimization. Furthermore, the new design approaches of smart response platforms (or bacterial-induced triggering systems) and targeting specific administration dosage forms for specific pathogens are also discussed as prospective strategies to address the remaining challenge of toxicity while maintaining or even enhancing antimicrobial potency.

Effects of Regioregularity of π ‐Conjugated Polymers Composed of Boron β ‐Diketiminate on Their Stimuli‐Responsive Luminescence

Abstract: π-Conjugated polymers composed of a boron β-diketiminate complex with different regioregularity are synthesized by using Suzuki–Miyaura and Yamamoto couplings. The films formed with the polymers show luminescence chromism upon exposure to solvent vapors. Most importantly, the chromic behavior depends on the regioregularity of the polymers. Wide-angle X-ray diffraction, thermal analysis, and density functional theory calculations suggest that the chromism can originate from the morphological change in the films and the alternation of the electronic nature of the main chains.

Cu‐Catalyzed Atom Transfer Radical Polymerization: The Effect of Cocatalysts

Abstract: Atom transfer radical polymerization (ATRP) is one of the most powerful methods to prepare well-defined (co)polymers. Cu-catalyzed ATRP methods are most commonly used because of the excellent control and tunable catalytic activities via ligand functionalization. This minireview summarizes the development of Cu-catalyzed ATRP in the presence of cocatalysts, which are used to regenerate CuI complex activators during polymerizations. Fundamentals of Cu-based ATRP catalysts are first introduced, followed by the discussion of different types of cocatalysts in different Cu-catalyzed ATRP methods. Recent developments of photochemical cocatalysts for oxygen-tolerant ATRP and ATRP using long-wavelength irradiation are highlighted, which significantly expand the applications of Cu-catalyzed ATRP. Methods to study the properties of cocatalysts and their roles in Cu-catalyzed ATRP are discussed, with an outlook for the future development of cocatalysts.

Conjugated Polymers: Where We Come From, Where We Stand, and Where We Might Go

Abstract: Conjugated polymers (CPs) are electronic materials which always attract the joint attention of synthetic chemistry, physics, and engineering. The present article deals with “classical” CPs such as polyacetylenes and polyarylenes, and also with more sophisticated cases such as ladder polymers and graphene nanoribbons. CPs exhibit a wide variety of fascinating electrical and optical properties which qualify them as active components of devices. Their performance, however, is shown to sensitively depend upon structural perfection and purity as well as on the thin-film morphology, which is also influenced by processing procedures. Nowadays, the need for innovative energy technologies and sustainable materials and processes as well as the emerging new opportunities of quantum technologies, are adding further momentum to CP research.

Polymeric nanoplatforms for the delivery of antibacterial agents

Abstract: Antibiotic therapy is the first choice for the treatment of bacterial infections in the clinic. However, the continuously increasing bacterial resistance makes traditional antibiotic therapy difficult to achieve ideal therapeutic performance, necessitating the development of new antibacterial strategies. Polymeric nanoparticles have received much attention in biomedical applications. They can be used as nanocarriers to deliver a variety of antibacterial agents to the infected area. Compared to traditional drug delivery systems, polymeric nanoparticles show various advantages, including improved drug stability, long circulation time, controlled drug release, selective drug accumulation, and so on. This review summarizes the current applications of polymeric nanoparticles for the delivery of antibacterial agents. First, an extensive review of the applications of polymeric nanoplatforms in the delivery of various antibacterial drugs is conducted. The mechanisms and strategies of various stimuli-responsive polymeric nanoplatforms are then discussed, especially focusing on how to improve the antibacterial efficacy and reduce the side effects. Finally, the challenges of future developments of polymeric nanoplatforms in the delivery of antibacterial agents are discussed.

Back to the Future with Biorefineries: Bottom‐Up and Top‐Down Approaches toward Polymers and Monomers

Abstract: The establishment of novel biomass processing schemes is key for achieving the much-needed carbon neutrality and counteract global warming. Biomass provides a range of monomers and macromolecules with great potential to replace petro-based materials in a wide range of applications. While important developments are ongoing in the biorefinery space, cross-sectoral, multidisciplinary partnerships are paramount to speed up and de-risk the industrialization of such technologies, and an integrated view is necessary to achieve process feasibility. This perspective explores both bottom-up and top-down approaches for biomass valorization based on the main natural polymers and monomers that can be extracted or isolated from biomass. A special emphasis is put on scalability, economic feasibility, and resource availability while the biggest challenges in the path toward the development of biorefineries are also discussed.

The Effects of Dehydration Temperature and Monomer Chirality on Primitive Polyester Synthesis and Microdroplet Assembly

Abstract: Synthesis of polyester gels via dehydration of α-hydroxy acids (αHAs) is a plausible route to form primitive functional polymers. αHApolyester gels assemble into membraneless droplets upon rehydration in aqueous media that can segregate and compartmentalize early biomolecules. However, conditions for polyester synthesis and microdroplet assembly have yet to be broadly explored. Thus, the effects of heat and monomer chirality on dehydration synthesis and assembly of homopolyester microdroplets are investigated using microscopy and mass spectrometry. Lower dehydration temperatures (≤80 °C) are observed to result in shorter polyesters than higher temperatures (up to 150 °C). After rehydration of polyester products, droplet assembly propensity correlates with longer polymer length. Low temperature (40 °C) dehydration yields only short polyesters and nearly no droplet formation. Finally, polyesters derived from dehydration/rehydration synthesis of homochiral lactic acid and phenyllactic acid monomers are of equal length and with a similar propensity for droplet assembly as those derived from racemic starting materials. These results suggest that polyesters and microdroplets derived from them can form under a wide variety of temperatures and from different monomer chiralities, enabling many possibilities for such systems to have played a role in systemic self-organization during the origins of life.

Elucidating the Size‐dependency of in Vitro Digested Polystyrene Microplastics on Human Intestinal Cells Health And Function

Abstract: The prevalence of microplastics (MPs) contamination in a broad spectrum of potable water sources has raised significant environmental and public health concerns. While evidence of ingested MPs bioaccumulation in the gastrointestinal tract (GIT) of aquatic and terrestrial organisms is mounting, the understanding of the effects of MPs on human gastrointestinal health remains scant. Herein, the potential deleterious biological effects of pristine and in vitro digested polystyrene (PS) MPs of varying sizes (i.e., 0.1, 1, and 10 µm) are systematically examined over a wide concentration range of 25–400 µg mL−1 on two human intestinal cell lines, namely Caco-2 and NCM 460. Specifically, significant internalization of 0.1 and 1 µm PS -MPs have been observed in both cell types 24 h postexposure. However, multiparametric dose and time-dependent analysis encompassing cell viability, reactive oxygen species (ROS), and nutrient absorption/metabolism measurement revealed no significant adversarial outcomes. Interestingly, it is found that the 0.1 µm PS-MPs can perturb redox homeostasis in NCM460 but not in Caco-2 cells. Based on the in vitro experimental boundaries and findings, it is concluded that ingested PS-MPs pose little acute cytotoxic harm to human gastrointestinal health.

Li‐salt Doped Single‐ion Conducting Polymer Electrolytes for Lithium Battery Application

Abstract: Traditionally solid polymer electrolytes (SPEs) for lithium battery application are made by dissolving a Li-salt in a polymer matrix, which renders both the Li+ cations, the charge carriers of interest, and the anions, only by-standers, mobile. In contrast, single-ion conductors (SICs), with solely the Li+ cation mobile, can be created by grafting the anions onto the polymer backbone. SICs provide the safety, mechanical stability, and flexibility of SPEs, but often suffer in ionic conductivity. Herein an intrinsically synergetic design is suggested and explored; one dopes a promising SIC, LiPSTFSI (poly[(4-styrenesulfonyl) (trifluoromethanesulfonyl)imide]), with a common battery Li-salt, LiTFSI. This way one both increases the Li+ concentration and transport. Indeed, systematically exploring doping, it is found that 50–70 wt% of LiTFSI renders materials with considerable improvements in both the (Li+) dynamics and the ionic conductivity. A deeper analysis allows to address connections between the ion transport mechanism(s) (Arrhenius/VTF), the charge carrier speciation and concentration, and the free volume and glass transition temperature. While no silver bullet is even remotely found, the general findings open paths to be further explored for SPEs in general and Li-salt doped SICs in particular.

Cross‐Linked Polymer Binder via Phthalic Acid for Stabilizing SiO x Anodes

Abstract: It is widely recognized that SiOx is a feasible anode material for the next generation lithium-ion batteries because of its high capacity, low cost, environmental friendliness, and abundant available storage. However, the enormous volume expansion and irreversible by-products during lithiation can result in the rapid capacity degradation and low coulombic efficiency. The commercial binders of carboxymethyl cellulose (CMC) and polyvinylidene difluoride cannot afford the volume change. Herein, a rational crosslinked binder is synthesized through an in situ condensation reaction between CMC and phthalic acid (PA). With rich hydroxyl groups bonded to the homogeneous SiO2 nanodomain, the enormous volume expansion of the SiOx anode can be restricted efficaciously. Therefore, the SiOx@CMC-PA electrode delivers a reversible specific capacity of 671 mAh g−1 at 500 mA g−1 after 200 cycles and a high average coulombic efficiency of 99.2%, much higher than 226.3 mAh g−1 of SiOx@CMC electrode. It demonstrates that this work offers a cost effective and available strategy to achieve high performance binder for Si-based anode materials.

Processing of Poly(lactic‐ <i>co</i> ‐glycolic acid) Microfibers via Melt Electrowriting

Abstract: Polymers sensitive to thermal degradation include poly(lactic-co-glycolic acid) (PLGA), which is not yet processed via melt electrowriting (MEW). After an initial period of instability where mean fiber diameters increase from 20.56 to 27.37 µm in 3.5 h, processing stabilizes through to 24 h. The jet speed, determined using critical translation speed measurements, also reduces slightly in this 3.5 h period from 500 to 433 mm min−1 but generally remains constant. Acetyl triethyl citrate (ATEC) as an additive decreases the glass transition temperature of PLGA from 49 to 4 °C, and the printed ATEC/PLGA fibers exhibits elastomeric behavior upon handling. Fiber bundles tested in cyclic mechanical testing display increased elasticity with increasing ATEC concentration. The processing temperature of PLGA also reduces from 165 to 143 °C with increase in ATEC concentration. This initial window of unstable direct writing seen with neat PLGA can also be impacted through the addition of 10-wt% ATEC, producing fiber diameters of 14.13 ± 1.69 µm for the first 3.5 h of heating. The investigation shows that the initial changes to the PLGA direct-writing outcomes seen in the first 3.5 h are temporary and that longer times result in a more stable MEW process.

Carbon Nanotubes‐Based 3D Printing Ink for multifunctional “artificial epidermis” with Long‐Term Environmental Stability

Abstract: 3D printing is a rapidly developing field because it has been widely used in the rapid design and manufacturing of flexible sensors to meet the needs of complex soft structures and devices. In this study, a composite hydrogel ink composed of polyvinyl alcohol, silk fibroin, conductive polymer, and carbon nanotubes is designed,and using 3D printing technology an “artificial epidermis” with long-term environment stability and self-healing ability is created. In addition, the “artificial epidermis” also has the multifunctional characteristics of sensing pressure, strain, temperature, and humidity. It has a wide pressure (0–165 kPa), strain (0–355%), temperature (−20–68 °C) and humidity (45–85%) sensing range and high sensitivity. While detecting the tiny movements of the human body, after self-healing, the device can fully restore its sensing capabilities and perform accurate human monitoring. Furthermore, it can also monitor changes in temperature and humidity, distinguish between hot and cold water, and perform detection of water droplets. Customized 3D printing of flexible electronic devices has opened up new ways for the biological integration of various sensors in wearable electronic systems and the application of advanced bionic skin.

RDRP (Meth)acrylic Homo and Block Polymers from Lignocellulosic Sugar Derivatives

Abstract: Currently, most commodity chemicals and polymers are manufactured from nonrenewable petroleum-based resources. However, due to its finite nature and social claims about environment preservation, alternative sources of value-added and building block chemicals are being intensively studied. Renewable lignocellulosic biomass has offered an attractive replacement for fossil-based chemicals. Lignin and C5/C6 sugars obtained from lignocellulosic biomass through chemical and enzymatic methods can be further transformed to targeted chemical platforms. In the present review, synthetic pathways for well-defined poly(meth)acrylates obtained from C5/C6 sugar-derived platforms in which the sugar structure is not retained are discussed. While bio-based polymers from these monomers are investigated using a wide range of polymerization techniques, this study focuses on precise synthesis of macromolecular structures taking advantage of reversible-deactivation radical polymerization methods and their applications.

Functional Applications of Polymer Electrolytes in High‐Energy‐Density Lithium Batteries

Abstract: Polymer electrolytes have attracted great interest in advanced lithium batteries. Recently, it has been found that there are many functional applications of polymer electrolytes in lithium batteries, which are very important for the development of high-energy-density lithium batteries. In this review, the functional applications of polymer electrolytes are reviewed in terms of protecting lithium metal anode, coating for high-voltage cathodes, and improving the safety of batteries. Finally, the remaining challenges and future perspectives of polymer electrolytes in these functional applications are presented. This review aims to provide a comprehensive understanding of polymer electrolytes and promotes their functional application in high-energy-density lithium batteries.

Trends in Polymer Degradation Across All Scales

Abstract: 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.

Self‐healable and Recyclable Sulfur Rich Poly(vinyl chloride) by S‐S Dynamic Bonding +

Abstract: In this work, a new approach to vulcanize commercial poly(vinyl chloride) (PVC) at room temperature and in a relatively short time (4 h) by using elemental sulfur and an initiator such as Na2S.9H2O is reported. The obtained crosslinked polymer contains polysulfide linkages that facilitate recycling/self-healing through dynamic S–S linkages. It is shown that PVC-polysulfide networks could be reprocessed at 180 °C for three times. The thermal and spectral characterizations of the polymers before and after recycling are performed via FT-IR, DSC, and TGA analyses. The potential use of the sulfur rich PVC-polysulfide system as cathode material for Li-S battery application is also investigated and the first discharge capacity is found to be around 610 mAh g−1 that later faded rapidly.

Deep Eutectic Solvent——A Novel Additive to Induce Gamma Crystallization and Alpha‐to‐gamma Phase Transition of PVDF

Abstract: Adding additives is the most convenient and effective way to induce polar poly(vinylidene fluoride) (PVDF) crystals which exhibit excellent ferroelectronic, piezoelectric, and dielectric properties. In this work, a kind of environmentally friendly additive, deep eutectic solvent (DES), is introduced to induce the crystallization of polar phases and accelerate the α-to-γ phase transition, which enables the fraction of γ(γ′)-phase crystals to exceed 90% in the PVDF/DES composite containing only 1 wt% DES. The ion–dipole interaction between PVDF and hydrogen bond acceptor in DES induces the polar molecular conformation, thus bringing about the formation of polar phase crystals. However, hydrogen bond donor promotes the dispersion of hydrogen bond acceptor in PVDF matrix, contributing to the flexibility of the composites.

Comb and Branch‐on‐Branch Model Polystyrenes with Exceptionally High Strain Hardening Factor SHF > 1000 and their Impact on Physical Foaming

Abstract: The influence of topology on the strain hardening in uniaxial elongation is investigated using monodisperse comb and dendrigraft model polystyrenes (PS) synthesized via living anionic polymerization. A backbone with a molecular weight of M w,bb = 310 kg mol − 1 is used for all materials, while a number of 100 short (SCB, M w,scb = 15 kg mol − 1 ) or long chain branches (LCB, M w,lcb = 40 kg mol − 1 ) are grafted onto the backbone. The synthesized LCB comb serves as precursor for the dendrigraft-type branch-on-branch (bob) structures to add a second generation of branches (SCB, M w,scb ≈ 14 kg mol − 1 ) that is varied in number from 120 to 460. The SCB and LCB combs achieve remarkable strain hardening factors (SHF) of around 200 at strain rates greater than 0.1 s − 1 . In contrast, the bob PS reach exceptionally high SHF of 1750 at very low strain rates of 0.005 s − 1 using a tilted sample placement to extend the maximum Hencky strain from 4 to 6. To the best of the authors’ knowledge, SHF this high have never been reported for polymer melts. Furthermore, the batch foaming with CO 2 is investigated and the volume expansions of the resulting polymer foams are correlated to the uniaxial elongational properties.

Catechin and Furfurylamine derived Biobased Benzoxazine with Latent‐Catalyst Effect

Abstract: Sustainable polybenzoxazines sourced from renewable feedstock has emerged as an area of interest due to the inherent presence of a high number of reactive and additional functionalities. Plants are a rich source of flavan-3-ol viz., catechin (CAT) with four phenolic-OH and one aliphatic secondary-OH that can be a viable substitute to petro-phenols. In this current work, a biobased benzoxazine monomer, viz. CAT-fa, is synthesized using CAT and carbohydrate sourced furfurylamine (fa). Interestingly, an unexpected tris-oxazine (instead of tetra-oxazine) benzoxazine monomer is obtained. The unreacted phenolic-OH is involved in intramolecular H-bonding with the neighboring oxazine ring. Upon heat treatment, H-bonded hydroxyl groups become free and initiate ring-opening polymerization reaction at a low temperature of ≈125 °C exhibiting the latent catalyst effect. The ring-opening polymerization of the monomer and the thermal stability of polybenzoxazine are analyzed by differential scanning calorimetry, thermal gravimetric analysis, rheometry, and Fourier transform infrared spectroscopy. The polymerization reaction is proposed to proceed by the ring-opening reaction by cleavage at the oxygen of the pyran ring and O─CH2N bond in oxazine ring to generate multiple polar functionalities to enable extensive H-bonding interactions. This work supports the potential of catechin as a green synthon to form sustainable polymers to employ H-bonding interactions and latent-catalytic potential.