Progress in Polymer Science最新文献

Polymers have many advantages such as low weight, low cost, and, importantly, stability under thermal, chemical, and mechanical stress. This stability, on the other hand, leads to criticism for causing environmental pollution on a macro-scale and via long-lasting microscopic plastic fragments (microplastics). Since it is very difficult but also very expensive to design brand-new materials that could both have the desired properties (mechanical, thermal, solvent resistance, etc.) and that are in the same time either recyclable and/or biodegradable, transforming already known materials to make them biodegradable/recyclable is more interesting. This approach relies on the introduction of labile/cleavable bonds onto the polymer backbone. The degradation could thus occur from these weak bonds leading to oligomers that could be easily recyclable and/or bioassimilable. This approach is currently applied to all polymerization techniques and led to interesting alternatives to numerous polymers ranging from polyolefins (polyethylene, polypropylene, …), polyethylene oxide, polyesters, polyamides, vinyl polymers, thermosets, etc. This review thus aimed at giving a comprehensive overview of the chemistries/monomers that could be used for the different polymerization processes but also described the alternatives to common polymers whatever the polymerization process. An emphasis will be put on the degradation/biodegradation/recycling properties of the new materials.

Bottom-up synthesis strategies to construct nano-architectonic material exhibiting specific properties by controlling the spatial distribution of the material units are challenging. Native polysaccharide nanocrystals, primarily cellulose and chitin nanocrystals (CNCs and ChNCs), possess excellent intrinsic biodegradability, biocompatibility, tailorable surface chemistry, and unprecedented optical and mechanical properties. These nanocrystals, in particular CNCs, have attracted considerable attention within the last years for constructing optical materials via bottom-up self-assembly. Here, the physicochemical mechanisms underlying the self-assembly of CNC nanocrystals and the structure-property relations of CNC nanocrystal assembly structures are summarized, including the transition from the isotropic phase at low concentrations to the cholesteric phase at high concentrations, and finally to dry films in a fixed state. The properties of aggregated and self-assembled CNCs are described in detail. Based on the dimensions of self-assembled structures as divided in zero-, one, two and three-dimensional constructions, recent advances of polysaccharide nanocrystals-based optical materials are discussed. Finally, the challenges of the methods for the environmentally benign preparation of polysaccharide nanocrystals are identified and the opportunities for realizing novel functional materials based on polysaccharide nanocrystal assembly are described.

Synthetic biodegradable elastomers, such as polyesters and polyurethanes have revolutionized biomedical therapeutic strategies and devices. Driven by innovations in chemical synthesis and processing technologies, a series of biodegradable elastomers and corresponding devices with controllable properties and various functionalities have been developed. In this review, we have summarized the recent progress in synthesis, process technologies, and biomedical applications of biodegradable elastomers. Particular emphasis is on the molecular design for biodegradability, elasticity, and the newly developed functionalities including self-healing, antibacterial, fluorescence, and shape-memory of biodegradable polyesters and polyurethane as well as their corresponding processing strategies. Subsequently, the recent progress of biodegradable elastomers in different biomedical applications is reviewed. A comprehensive conclusion and outlook pointing out emerging research directions, future challenges and potential solutions complete this work.

With the growing demand for clinically reliable therapeutics, traditional small molecule drugs are increasingly limited by their short circulation duration, low bioavailability, and poor targeting. Protein drugs, on the other hand, have gained popularity due to their high activity, high specificity, low cytotoxicity, and distinct biological function. Especially, monoclonal antibodies are among the top 10 drugs in global sales. However, protein drugs have limitations such as complex and unstable structure, immune clearance caused by antigen fragments on the surface, and inability to penetrate cell membranes, which severely restrict intracellular delivery. Using carriers can greatly enhance the stability of protein drugs, prevent immune clearance, and facilitate their cellular uptake and cytosolic release. Polymers are commonly used for delivering small molecules, DNA, and RNA. However, developing polymers for protein delivery with high efficiency and low cytotoxicity still faces several challenges, including poor protein binding ability, membrane impermeability, and low endo/lysosomal escape efficiency. Functionalizing polymers with specific components such as fluorine, boron, guanidine, heterocycles, and multicomponents can improve polymer-protein interaction, cell membrane penetration, endo/lysosomal escape, and biocompatibility. This review provides an overview of strategies for polymer functionalization and their effects on protein delivery. It also discusses trends and challenges in developing polymer carriers for protein delivery.

The mechanically hard phase and ionically conductive phase endow suitably designed block copolymer electrolytes (BCPEs) with the “Janus” property, thus providing the opportunity to decouple the trade-off between mechanical strength and ionic conductivity by controlling the phase-separated structures. The conductivity of BCPEs is predominantly determined by the molecular structure of block copolymers and the type and concentration of additives, while the manipulation of phase-separated structures helps strengthen their mechanical support and ion transport. This review article presents an overview of BCPEs and focuses on the “molecular structure-phase structure-property” relationship. Ideally, BCPE membranes should have high-throughput and aligned ion transport channels perpendicular to electrodes. First, given the desired attributes of polymer electrolytes, i.e., high ionic conductivity, high strength, low thickness, and high limiting current density, we summarize the research status and optimization strategies for BCPEs. Second, we present a summary of methods that control the phase behavior of BCPEs based on the phase separation mechanism. Third, BCPEs are classified into dual-ion conductor and single-ion conductor, whose advantages and disadvantages are analyzed. Furthermore, we propose a design rationale for high-performance quasi-solid-state BCPEs. We elaborate polymerization methods for the regulation of molecular and phase structure. These aspects are believed to collectively contribute to BCPE membranes with both high ion-conductivity and high mechanical strength, further boosting the development of safe and high-energy solid-state lithium metal batteries.

This review presents the state of the art of complex macromolecular architectures based on polylactide stereocomplexes (PLA-sc) from the viewpoint of synthesis and crystallization. First, we discuss the nomenclature, synthesis, epimerization, and lactide (LA) properties as a bio-derived cyclic dimeric monomer comprising two chiral carbons. Among several polymerization methods, catalytic ring-opening polymerization (ROP) is the most common and versatile technique to access stereoregular (isotactic) PLA, which is the prerequisite to preparing PLA-sc. Combined with other living and controlled/living polymerization techniques, ROP of LA has yielded various PLA-sc-based macromolecular architectures, including copolymers, stars, graft, cyclic, brush, and hybrid materials. New approaches to synthesizing monodisperse discrete oligoLA are also discussed. We show that a small change in the architectures, microstructures, molecular weight, or other chemical and physical modifications affects the behavior of PLA-sc. Moreover, the crystallization of PLA-sc, after more than 30 years of study, still presents many challenges. The crystalline morphology is also a subject of debate. Recent findings suggest a new crystalline unit cell for PLA-sc. Adding a third component or changing chain architecture can significantly modify the properties of the formed PLA-sc. The complex relationship between flexibility, nucleation, diffusion, and the interactions needed for the joint crystallization of the enantiomers constitutes a very large source of variables. As a result, PLA-based stereocomplex materials can be tailored by manipulating one or several of these variables.

ο-Nitrobenzyl (ONB) derivatives are one of the most investigated photo-responsive functional group that features irreversible photolysis under a light stimulus. They are easy to synthesize and display excellent photoactivity, thus have been widely used to construct photo-responsive polymers for numerous applications, such as controlled drug delivery, photodegradable materials, photoinduced micropatterns, etc. This review article is focused on ONB derivatives and their developments in polymer science. The article provides an up-to-date information, including photolysis mechanism, structural design, and materials properties, with a special focus on the application development of ONB derivatives in different areas of polymer science. In addition, the challenges and outlook based on our understanding are also provided. We believe this article will be of interest to the readers from both scientific and industrial communities and will help the readers understand the latest developments in the field, thereby enlightening thoughts for the design of photo-responsive polymers.

Polydopamine (PDA) is a fascinating bioinspired material for the construction of diverse functional materials. In particular, the growing trend of PDA hydrogels clearly reveals the global significance and the intense interest of scientific research in this field. The abundant functional groups make PDA serve as the important structural units for covalent or/and non-covalent interactions with polymers, and anchoring of transition metal ions for hydrogels formation. With these benefits, PDA not only endows hydrogels with various functions such as adhesion, photothermal effect, ultraviolet protection, antioxidant ability, antibacterial properties, but also has been rapidly incorporated into a wide range of applications across the biomedical, environment, energy, and electronic fields. This review strives to provide a comprehensive overview of the relevant advances in the field of bioinspired PDA hydrogels. We start to introduce the PDA as the structural units in hydrogels and dedicate a lot of space to discuss their design and PDA functions in the hydrogels. Furthermore, these functions would bring about various interesting applications of the hydrogels. Some key issues in this emerging field have been also exhibited into discussion which will inspire our thinking in functional hydrogels design.

In polymer science, thermoresponsiveness refers to macromolecular systems that display a marked and discontinuous change in their physical properties with temperature. Such smart polymers are the focus of increasing attention as they provide new solutions to many applications (e.g., drug delivery, nanotechnology, tissue engineering and biotechnology). This review focuses on amino acid based polymers, mainly synthetic polypeptides that are obtained by ring-opening polymerization. These include polymers based on natural amino acids, synthetic or modified amino acids and N-alkylated glycine derivatives. Based on what is known about the behavior of natural proteins in response to temperature variations, this review provides a comprehensive overview of the state of the art of thermosensitive polypeptides through a detailed description i) of the structure/thermoresponsiveness relationship, ii) of the mechanisms involved at the molecular level, iii) of their possible applications both in materials science and in biomedical applications.

The introduction of chemical and/or optical nonlinearity to 3D-printing has paved the way towards volumetric 3D-printing, enabling remarkable advancements in speed, resolution, and the fabrication of previously inaccessible materials. Given the growing interest of the scientific community, we present a critical review that aims to provide a comprehensive discussion of the potential of volumetric 3D-printing. First, the theoretical framework of photopolymerization is summarized. Subsequent sections highlight the progression of light-based 3D-printing from traditional to emerging volumetric 3D-printing techniques, encompassing both single- and multi-photon polymerization. Special attention is given to the rapidly advancing subfield of volumetric bioprinting which holds great promise for the fabrication of complex multi-material tissue constructs. Finally, critical considerations and limitations of volumetric 3D-printing as well as prospective solutions and opportunities for future research are discussed to allow readers to appreciate and participate in the exciting and rapidly advancing field of volumetric 3D-printing.