最新刊期
- 摘要：Flexible display cover materials face the challenge of balancing high transparency, high temperature resistance, and complex service reliability. In this work, a series of colorless transparent polyimide (CPI) films were prepared by regulating the rigidity of molecular chains and free volume. It was found that as the rigidity of the molecular chains increased, the glass transition temperature (Tg) and hydrophobicity of the samples improved, while the mechanical properties showed a stronger correlation with the packing density of the molecular chains and the content of hydrogen bonds. Among them, CPI-CBDA, which contains a rigid non-conjugated cyclobutane structure, has small free volume, many hydrogen bonds, and a tightly packed molecular chain, and thus combines high transparency (average transmittance Tav in the range of 380-780 nm was 87.02%), high heat resistance, low expansion (average thermal expansion coefficient CTE in the temperature range of 50-250 ℃ was 10.52×10-6/K), and excellent mechanical properties. In terms of service evaluation, after 5×105 dynamic bends (bend radius R=2 mm), the Tav loss rate of most samples was less than 3%, and the tensile strength retention rate was higher than 85%, while the strength retention rate of commercial PET films was lower than 56%. It is worth noting that after bending, the Young's modulus of some samples increased instead, possibly due to the local cyclic strain inducing molecular chain orientation. The ultraviolet aging study shows that CPI-CBDA has the best stability. Its aging mechanism shows a staged characteristic: initially, the cyclobutane structure decomposes, then weak bonds break, while cross-linking reactions occur between molecular chains simultaneously, compensating for the degradation of mechanical properties, and its Tav retention rate after ultraviolet irradiation is as high as 97.1%, and the retention rates of tensile strength and modulus even reach 119.4% and 140.1%.关键词：Colorless and transparent polyimide;Molecular structure regulation;Dynamic bending durability;UV irradiation resistance125|17|0更新时间：2026-07-10
- 摘要：The interfacial instability of high-voltage layered lithium nickel-cobalt-manganese oxide cathode materials, characterized by excessive electrolyte decomposition, transition metal dissolution, and cation mixing, severely limits their cycle life. In this work, an acrylate copolymer (PMHC) containing both hydroxyl and cyano groups was designed and synthesized. This copolymer coated the surface of LiNi0.6Co0.2Mn0.2O2 (NCM622) particles during the cathode slurry preparation process and undergoes in situ cross-linking via the Ritter reaction, forming a stable polymer interface layer to enhance cathode performance. Density functional theory (DFT) calculations revealed that the binding energy between the cyano group and the NCM622 (-1 0 0) crystal plane (-24.35 eV) was much higher than that of the fluorine-containing group in PVDF (-14.62 eV), facilitating preferential adsorption and coating of the polymer. Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS) studies indicated that PMHC polymer undergoes cross-linking in the presence of Lewis acid. Transmission electron microscopy (TEM) confirmed the successful coating of the cross-linked PMHC polymer on the NCM622 surface. Cyclic voltammetry (CV) tests demonstrated that the coating layer significantly reduces polarization and increased the apparent diffusion coefficient of Li+. Battery test results showed that the coating layer contributed to the structure stability of the cathode material. The PMHC@NCM cell exhibited a very high specific discharge capacity (146.7 mAh·g-1) and Coulombic efficiency (99.78%) after 400 cycles at 0.5 C. XPS analysis further revealed that the cross-linked polymer coating participates in the formation of the cathode electrolyte interface (CEI) layer, and this polymer-derived CEI effectively suppressed cation mixing, transition metal dissolution, and electrolyte decomposition. This work presents a new strategy for stabilizing high-voltage cathode material interfaces through polymer coating followed by in situ cross-linking, offering a novel approach to improve the cycle life of high energy-density lithium-ion batteries.关键词：Cathode coating;In situ cross-linking;Ritter reaction;NCM622;Lithium-ion battery2|0|0更新时间：2026-07-10
- 摘要：To address the urgent demand for low-dielectric-constant polymer dielectrics in high-frequency communication technologies, this study proposes a new strategy for modulating chain conformation through main-chain engineering to reduce the dielectric constant (Dk) and dielectric loss (Df). Distinct from conventional approaches that enhance rigidity or introduce flexible segments, we aimed to introduce controlled molecular twists while maintaining main-chain rigidity, thereby simultaneously increasing free volume and restricting dipole motion. To this end, two novel asymmetric single-quinoxaline-based difluoro monomers with different bond angles were designed and synthesized, and copolymerized with the fluorinated bisphenol 6F-BPA to successfully prepare poly(aryl ether)s, namely P6FEQA and P6FEQD, with varying degrees of main-chain twisting. For comparison, a linear polymer, P6FEQ, was synthesized using a symmetric bis-quinoxaline monomer. Systematic investigations revealed that increasing the degree of main-chain twist effectively attenuates the macroscopic polarization response by reducing packing density and strongly suppresses dipole relaxation through conformational locking. Among the obtained polymers, P6FEQD, which exhibited the highest degree of twisting, demonstrated the most outstanding dielectric performance at 15 GHz, with a Dk as low as 2.385 and a Df of only 0.00344, which was nearly an order of magnitude lower than the typical loss values of commercial poly(ether ether ketone) (PEEK) in the GHz frequency range. Notably, the monomers employed are readily synthesizable. This work provides a clear paradigm and mechanistic elucidation for achieving high-frequency dielectric performance optimization through "rigid-twist" molecular design.关键词：Poly(aryl ether);Quinoxaline;Asymmetric monomer;Low dielectric constant;Low dielectric loss65|15|0更新时间：2026-07-10
- 摘要：The tendency of poly(acrylic acid) (PAA) and poly(ethylene oxide) (PEO) to readily form complexes in solution is one of the key factors limiting the fabrication of PEO/PAA electrospun membranes. In this study, PEO/PAA porous fiber membranes were fabricated via electrospinning using a solvent mixture of N,N-dimethylformamide and acetone at a volume ratio of 7:3. It was found that both the polymer concentration in the spinning solution and the PEO-to-PAA mass ratio exerted significant influences on the structure and properties of the porous fiber membranes. The membrane exhibited the most uniform fibre morphology under the mass fraction of 6 wt%. Moreover, the membrane showed shape-memory behaviour and humidity responsiveness at a mass ratio of 5:1. After experiencing 40% tensile deformation, the membrane recovered to its original shape when heating at 60 ℃. Once the membrane placed on human hand, it could deform rapidly in a direction opposite to the hand. Furthermore, the membrane exhibited the optimal mechanical performance with an elongation at break up to 882% when the mass ratio was 1:1. The liquid metal was blade-coated onto the membrane surface for assembling a capacitive wearable sensor, which displayed excellent elastic recovery and wide-range strain response. The sensor also maintained stable and reliable sensing performance even suffered to 2000 cycles at 100% strain. Besides, the sensor could detect the finger bending, wrist motion, swallowing and chewing. This work provides a convenient electrospinning strategy and sensor preparation strategy for PEO/PAA porous fibrous membranes.关键词：Electrospinning;Sensor;Humidity response;Shape memory70|25|0更新时间：2026-07-10
- 摘要：In this study, a top-down strategy was adopted for the synthesis of poly(ester-carbonate) diols (PPCP-DL) by hydrolyzing high-molecular-weight poly(acetal-co-ester-co-carbonate) (PPCP-PAc). First, the nonmetal catalyst triethylborane (TEB)/tetrabutylammonium chloride (TBACl) was used to catalyze the quaternary copolymerization of propylene oxide (PO), carbon dioxide (CO2), phthalic anhydride (PA), and o-phthalaldehyde (OPA), affording high-molecular-weight PPCP-PAc with varied segmental compositions. Subsequently, the acetal linkages in the polymer backbone were selectively hydrolyzed under mild acidic conditions, yielding a series of low-molecular-weight PPCP-DLs with different molecular weights (1.6-3.3 kg/mol) and polyester (PE) contents (13 mol%-37 mol%). The end-group structures of PPCP-DL, confirmed by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and 19F nuclear magnetic resonance spectroscopy, revealed hydroxyl groups at both termini and a primary hydroxyl content of 43 wt%.关键词：Carbon dioxide;Poly(carbonate diol);o-Phthalaldehyde;Hydrolysis125|25|0更新时间：2026-07-10
- 摘要：Diels-Alder (DA) dynamic covalent polyurethane (DAPU) elastomers are highly regarded in the field of self-healing materials due to their excellent mechanical properties and thermo-reversible healing capabilities. In this study, we employed a literature data-driven approach to investigate the structure-property relationships governing the tensile strength, elongation at break, and healing efficiency of DAPU elastomers. By systematically screening the formulation and performance data from the relevant literature, we constructed a comprehensive feature space spanning the compositional content, chemical characteristics, and structural mechanisms. Three machine learning models, namely Support Vector Regression (SVR), XGBoost, and Gaussian Process Regression (GPR), were established to quantitatively analyze these properties, yielding R2 values of 0.76, 0.66, and 0.81, respectively. The results demonstrate that the proposed feature system effectively captures the relationships between the key structural variables and properties of DAPU elastomers. Subsequent SHapley Additive exPlanations (SHAP) analysis revealed that soft-segment crystallinity and soft-segment molecular weight were the most critical parameters governing mechanical strength and healing efficiency, whereas DA functional monomer content was the primary determinant of ductility. Furthermore, complex non-monotonic correlations were identified among the three properties. This work provides a reference for understanding DAPU structure-property relationships and guiding rational-formulation design.关键词：Polyurethane;Diels-Alder dynamic bonds;Self-healing elastomer;Machine learning;Structure-property relationships;Literature data-driven103|38|0更新时间：2026-07-10
- 摘要：With the increasing power density of electronic devices, efficient thermal management is essential for improving device reliability. Polymer-based composites are promising thermal management materials because of their low density, good processability, and structural flexibility. However, the low intrinsic thermal conductivity of polymer matrices limits their heat dissipation capability. Increasing filler loading can improve heat conduction, but excessive filler content often deteriorates mechanical, electrical insulating, and processing properties. Therefore, improving filler utilization efficiency at a moderate filler fraction is important. In this work, topology optimization was used to guide the design of graphite filler structures in polydimethylsiloxane (PDMS) composites. Based on finite element simulations, a simple dumbbell-shaped graphite filler was proposed. This structure contained a continuous central heat-conduction path and expanded end regions, which could reduce through-plane thermal resistance and promote lateral heat spreading. Graphite/PDMS composites with cubic, cylindrical, frustum-like, and dumbbell-shaped fillers were fabricated by computer numerical control machining, followed by PDMS encapsulation and curing. Infrared thermal imaging and heat-flow-based tests were used to evaluate their thermal responses. Compared with conventional cylindrical and cubic fillers, the dumbbell-shaped filler produced a more uniform temperature distribution and stronger hotspot suppression. Under vacuum conditions, the hot-cold side temperature difference was reduced by 8.6 and 5.4 ℃, respectively. The dumbbell-array composite showed a heat dissipation efficiency of 0.028 W·℃⁻1, 1.47 times that of the cylindrical-array composite. This work provides an effective strategy for designing conductive filler architectures in polymer-based thermal management composites.关键词：Polymer composites;Topology optimization;Thermally conductive fillers;Thermal management247|40|0更新时间：2026-07-10
- 摘要：Owing to the tissue-like mechanical properties and environmental responsiveness, hydrogels exhibit great potential in diverse fields, including aerospace, biomedicine, and flexible electronics. Their surfaces are the regions interacted with other objects during utilizations, which are essential to the realization of functions. However, conventional homogeneous hydrogels are hard to meet precise requirements of surface characteristics in complex scenarios, limiting the expansion of their applications. To address this, recent studies have focused on patterning the surface properties of hydrogels, such as wettability, adhesion, and optical properties. Many strategies are developed enabled by different chemical or physical procedures, thus meeting the differential demands of scenarios. This review focuses on patterning of hydrogel surface properties, summarizing recent achievements in this field. Furthermore, it provides a perspective about the latest opportunities and challenges according to our research. Especially, we emphasize the approach and merits of patterning hydrogel surfaces via photochemistry to give valuable references for future works.关键词：Hydrogels;Surface properties;Patterning;Stimuli-response;Functionalities2|0|0更新时间：2026-07-10
- 摘要：To address the issues of molecular chain aggregation and film thickness-dependent luminescence encountered by polyfluorenes in practical applications, a novel polyfluorene-based deep-blue semiconductor material PHDPF-DPA was designed and synthesized via a steric hindrance encapsulation strategy in this work. The results demonstrated that the steric hindrance effect of the diphenylamine side chains endowed the material with excellent thermal stability, which could effectively suppress interchain aggregation, reduce low-energy defect emission, and prevent erosion by water and oxygen, thereby significantly improving the stability of blue-light emission. The photophysical properties of this material showed no obvious dependence on film thickness. Transient absorption measurements further revealed that the steric groups can efficiently weaken exciton annihilation and enhance exciton utilization. Under optical pumping, the film exhibited deep-blue amplified spontaneous emission (ASE) with a threshold of 6.17 μJ/cm2 and a full width at half maximum (FWHM) of only 1.4 nm. Polymer light-emitting diodes (PLED) fabricated with this material as the emitting layer achieved stable deep-blue electroluminescence. This work verifies the effectiveness of the steric hindrance encapsulation strategy for constructing high-performance and stable polyfluorene-based blue-light semiconductors, and provides an important foundation for the application of printing techniques in the preparation of organic optoelectronic devices.关键词：Light-emitting conjugated polymers;Polyfluorene-based blue light semiconductor;Steric hindrance encapsulation;Amplified spontaneous emission;Organic light-emitting diode110|20|0更新时间：2026-07-10
- 摘要：Lubrication and protective coatings applied to the surfaces of moving mechanisms in nuclear reactors face the dual challenges of long-life lubrication and long-term radiation stability. In this study, polysilazane (PSZ), a precursor with excellent potential for nuclear radiation resistance, was adopted as the base resin binder, and molybdenum disulfide (MoS2) was incorporated as the lubricating filler to prepare a PSZ-bonded solid lubricating coating with favorable lubricating and radiation-resistant properties. The variations in the composition, structure, mechanical properties, and tribological properties of the coating after heat treatment at different temperatures and before and after gamma-ray irradiation were systematically investigated. The results show that both high-temperature heat treatment at 300 ℃ and γ-ray irradiation can promote the cross-linking and curing of the PSZ composite lubricating coating, thus significantly improving the hardness and tribological properties of the composite coating. In particular, the composite coating subjected to the combined treatment of 300 ℃ high-temperature heat treatment and gamma-ray irradiation exhibited outstanding wear resistance, with an average friction coefficient of approximately 0.34 and a wear rate as low as 6.7×10-5 mm3/(N·m). The composite coating exhibited excellent tribological properties and γ-ray radiation resistance. The above research findings provide technical support and theoretical guidance for surface lubrication and protection of relevant mechanically moving components in advanced nuclear reactors under high radiation dose conditions in the future.关键词：Polysilazane;Lubricating coating;γ-ray irradiation;tribological performance339|112|0更新时间：2026-07-10
- 摘要：Using polycarbonate diol as the soft segment and 1,4-butanediol as the chain extender, polyurethanes with alicyclic hard segments (R-PCPU) and aliphatic hard segments (L-PCPU) were synthesized using isophorone diisocyanate (IPDI) and hexamethylene diisocyanate (HDI), respectively. A series of R-PCPU/L-PCPU blends (PUB) with different mass ratios were prepared via solution blending. The structure and properties of PUB were characterized using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analyze (TGA), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and a universal testing machine. The results showed that, owing to the steric hindrance of the hard segments, hydrogen bonding and microphase separation were stronger in L-PCPU than in R-PCPU, and both properties in PUB increase with increasing L-PCPU content. R-PCPU primarily exhibited soft-segment crystallization (melting temperature of approximately 43.26 ℃), whereas L-PCPU exhibited hard-segment crystallization (approximately 168.66 ℃). PUB exhibited crystallization behavior in both soft and hard segments. As the L-PCPU content increased, the crystallinity of the soft segment decreased, whereas that of the hard segment increased. Benefiting from the synergistic effects of the ring-shaped and linear hard segments, PUB exhibited controllable mechanical properties, with an elongation at break (up to 900%) higher than that of R-PCPU and a tensile strength (up to 75.62 MPa) higher than that of L-PCPU. Furthermore, the synchronized crystallization behavior of the soft and hard segments endowed PUB with excellent shape memory properties, making it significantly more valuable than R-PCPU or L-PCPU. Owing to its comprehensive performance advantages, PUB showed great potential for application in the field of smart medical devices, such as orthodontic wires and self-contracting sutures. This study also provides a novel strategy for the structural design and simple preparation of shape memory polyurethane.关键词：Polyurethane blends;Hard segment structure;Hydrogen bonding;Shape memory property;Mechanical property85|6|0更新时间：2026-07-10
- 摘要：Biodegradable stents are widely used in the treatment of vascular stenosis. However, post-implantation complications such as in-stent restenosis often lead to an increase in local blood pressure, significantly impacting patient prognosis. Therefore, continuous in situ monitoring of intravascular pressure holds significant early-warning potential. However, existing pressure sensors face challenges in terms of structural compatibility, service lifetime, and degradation behavior, limiting their clinical application. To address these challenges, this study proposed a design strategy that synergistically integrates pressure monitoring with degradable performance. A coaxial multilayer biodegradable capacitive pressure-sensing fiber was developed to match and integrate with the biodegradable stent. It was constructed using collagen surgical sutures as a flexible substrate, with conductive gold electrodes formed via thermal deposition, a poly(citrate) dielectric layer, and a polycaprolactone encapsulation layer. By regulating the composition and structure of the polymers, synergistic optimization of sensing performance and degradation rate was successfully achieved. The fabricated sensing fiber demonstrated a sensitivity of 0.051 kPa-1 within 0~25 kPa (covering the physiological intravascular pressure range) and exhibited good biocompatibility. When integrated with a biodegradable stent, it provides short-term monitoring capabilities and long-term degradability, offering a novel approach for the development of biodegradable smart vascular stents and the functionalization of other implantable medical devices.关键词：Fiber electronics;Pressure monitoring;Sensing fiber;Biodegradable materials;Vascular stent60|17|0更新时间：2026-07-10
- 摘要：Persistent hypoxia is a critical factor limiting tissue regeneration during chronic wound healing, highlighting the importance of developing polymer-based systems capable of controlled oxygen delivery. In this work, we constructed a reaction-transport coupled oxygen-generating system based on multi-interface regulation by a polydimethylsiloxane (PDMS) membrane and an alginate hydrogel. Through a multilayer structural design, the system spatially integrated hydrogen peroxide (H2O2) storage, transmembrane diffusion, interfacial catalysis, and oxygen transport into a hierarchical pathway, enabling coordinated control over reaction and mass transport processes. The PDMS membrane served as a key transport-regulating interface, where membrane thickness governs the flux of H2O2, converting its intrinsically rapid decomposition into a diffusion-controlled and stabilized reaction process. The MnO2 catalytic layer provided a solid-gas interfacial reaction environment, while the hydrogel interface facilitated the conversion of oxygen from gaseous to dissolved form and promotes its transport into surrounding tissue. Experimental results demonstrated that the system enabled sustained and stable dissolved oxygen output, significantly improving cell viability under hypoxic conditions. In a diabetic wound model, the system markedly accelerated wound healing, accompanied by enhanced collagen deposition and neovascularization. This work reveals a materials design strategy based on multi-interface coordination of reaction and transport processes, providing new insights into the development of functional polymer systems for hypoxia-related diseases.关键词：Polydimethylsiloxane;Hydrogel dressing;Dissolved oxygen;Chronic wound73|3|0更新时间：2026-07-10
- 摘要：Hyperbranched polymers are a class of important polymers with unique physicochemical properties. The synthesis of cleavable hyperbranched polymers is of great significance in the fields of biomedical and materials science. In this study, a novel xanthate chain transfer agent was designed and used to mediate the RAFT polymerization of vinyl acetate and AB2-type precursor polymers were synthesized. The precursors were subsequently used in one-pot synthesis of cleavable hyperbranched polymers via sequential thiol-xanthate and thiol-phenylsulfone reactions. The thioether bonds in the polymer structures can be cleaved by small molecular thiol compounds under alkaline catalysis. The chain extension process was monitored by 1H-NMR and GPC. The influences of the factors, including the degree of polymerization of the precursor, feed ratio, temperature, and chain extension initiator, were investigated. The strategy based on a combination of RAFT polymerization and thiol chemistries, offers a new and effective approach to the synthesis of cleavable hyperbranched polymers.关键词：Hyperbranched polymer;Cleavable polymer;RAFT polymerization;Thiol-xanthate reaction;Thiol-phenylsulfone reaction52|14|0更新时间：2026-07-10
- 摘要：Conjugated polymers exhibit broad application prospects in fields such as thermoelectric conversion and flexible electronics due to their advantages of light weight, flexibility, and solution processability, with doping being a key strategy for achieving high electrical conductivity. However, single molecular doping often struggles to simultaneously balance carrier concentration and structural order. In this work, we proposed a sequential dual-doping strategy using poly(3-hexylthiophene-2,5-diyl) (P3HT) as a model system. F4TCNQ was first introduced into the polymer, followed by deep redox doping with FeCl3. The results showed that F4TCNQ pre-doping expanded the alkyl side-chain spacing while maintaining structural order, thereby constructing favorable channels for subsequent FeCl3 diffusion and charge transfer. During the secondary doping step, the stronger oxidizing agent FeCl3 partially replaced F4TCNQ, while the sequentially dual-doped film maintained high crystalline order along with a more compact π-π stacking distance and stable molecular orientation. Sequential dual-doping promotes the transition tendency from polarons to bipolarons, reduces spin concentration, and achieves higher carrier concentration and mobility compared to single-doping systems. Under optimal conditions, the sequentially dual-doped P3HT film achieved an electrical conductivity of 595.9 S/cm, which was 10.6-fold and 9.4-fold higher than those of films doped with FeCl3 alone and F4TCNQ alone, respectively. The "structure optimization first, deep doping second" strategy proposed in this study provides an effective route toward high electrical conductivity in conjugated polymers.关键词：Conjugated polymers;Poly(3-hexylthiophene-2,5-diyl);Sequential dual-doping;F4TCNQ;Ferric chloride98|37|0更新时间：2026-07-10
- 摘要：With the development of personal radiation protection and flexible protective equipment, gamma-ray shielding materials face higher requirements for lightweight, flexibility, and lead-free characteristics. To improve the gamma-ray shielding performance of flexible polymer-based composites, we prepared Bi2WO6 and Bi2WO6/PAN composite nanofibrous membranes with different La doping contents using polyacrylonitrile (PAN) as the matrix. Combined with microstructural characterization and performance testing, the effects of La doping on the microstructure, local electronic structure, mechanical properties, and gamma-ray shielding performance of the composite nanofibrous membranes were systematically investigate. The results showed that La doping significantly regulates the crystallization behavior of Bi2WO6 and the growth state of the inorganic phase on the fiber surface, and the relationship between La doping content and the properties of the composite nanofibrous membranes was not simply linear. Appropriate La doping improved the distribution uniformity of the inorganic phase on the fiber surface and optimizes the membrane structure, whereas excessive doping caused the formation of La-containing impurity phases and local aggregation. The 10 wt% La-doped sample exhibited the best overall performance, with mass attenuation coefficients of 4.426, 1.491, and 1.315 cm2·g-1 under three irradiation conditions, which were approximately 51.6%, 77.7%, and 151.4% higher than those of the undoped samples, respectively. This study provides a reference for the structural design and performance optimization of lightweight, flexible, and lead-free gamma-ray shielding fibrous materials.关键词：Polyacrylonitrile;Bismuth tungstate;Crystallization behavior;Polymer matrix composites;Radiation protection141|20|0更新时间：2026-07-10
- 摘要：Biodegradable polyesters are promising alternatives to conventional petroleum-based plastics owing to their favorable bio-based origin, biocompatibility, and degradability. Achieving precise control over the microstructural sequence structure distribution of copolyesters during the ring-opening polymerization (ROP) of cyclic esters is a critical scientific challenge. To address this issue, this feature article summarizes recent advances in the sequence control of alternating copolyesters, with an emphasis on two representative strategies: (i) the regioselective ROP of asymmetric cyclic diesters, elucidating the regulatory mechanisms governing selective ester bond cleavage via electronic and steric effects, and (ii) the stereoselective ROP of chiral cyclic esters, the roles of syndioselective polymerization in achieving dyad sequence control, and heteroselective copolymerization in achieving triad and tetrad sequence control are summarized. Furthermore, the critical role of catalysts/initiators in balancing monomer reactivity, enhancing the regioselectivity and stereoselectivity of the polymerization system, and tailoring the polyester topology is discussed. It was further demonstrated that precise sequence control significantly improved the thermal properties, mechanical performance, degradation behavior, and drug release characteristics of copolyesters. Finally, future directions in this field are discussed.关键词：Sequence control;Alternating copolyesters;Ring-opening polymerization;Regioselectivity;Stereoselectivity182|26|0更新时间：2026-07-09
- 摘要：Secondary structure of proteins greatly matters the functions, making the study of polymer-protein interactions and their regulatory mechanisms of great significance. Linear poly(acrylic acid) (PAA) affects protein function by interacting with positively charged amino groups on proteins or by altering their secondary structure. However, the impact of other topological PAAs on protein conformation and functions remains unexplored. This study employed a research strategy of comparing molecular weights under the same topological structure and comparing topological structures under similar molecular weights. Through controlled polymerization and click chemistry, a series of linear and brush-type PAAs with different molecular weights were synthesized. Circular dichroism (CD) chromatography was used to investigate the regulatory effects of polymer molecular weight and topological structure on protein conformation and function. First, in the linear PAA system, it was found that low-molecular-weight linear PAAs could significantly convert low-molecular-weight proteins from α-helices to β-sheets in a short time; the higher the PAA molecular weight, the longer the incubation time required for the protein conformational transition to equilibrium. Comparing linear and brush-type PAAs with similar molecular weights, the brush-type PAA significantly accelerated the conformational transition of low-molecular-weight proteins from α-helices to β-sheets. For high-molecular-weight proteins, both topologic PAAs still changed protein conformation greatly, but no clear dependence on polymer molecular weight or topology was observed. Furthermore, we evaluated the functions of two proteins in the presence of topological PAAs. For β-galactosidase, molecular bottlebrush PAA stabilized enzyme activity, while linear PAA rapidly destroyed it. In mouse immunization with ovalbumin (OVA) as a model antigen, linear PAA induced significantly higher OVA-specific IgG titers and splenocyte IFN-γ secretion than molecular bottlebrush PAA. Combining conformation change by CD, we speculated that the drastic remodeling by molecular bottlebrush PAA could damage critical epitopes of OVA, whereas the mild modulation by linear PAA preserved epitope integrity. In conclusion, polymer molecular weight and topology are important parameters for regulating protein structure and function.关键词：Polymer topology;Poly(acrylic acid);Molecular bottlebrush;Protein conformation;Adjuvants4|1|0更新时间：2026-07-08
- 摘要：In response to increasingly stringent regulations on per- and polyfluoroalkyl substances (PFAS) and the demand for halogen-free thin-wall flame-retardant polycarbonate (PC) with low heat and smoke release, a naphthalimide-functionalized polysiloxane (PSNI) was designed and synthesized. PSNI was synergistically combined with kaolin to prepare a series of PC/PSNI/Kaolin composites, and the effects of the compounding ratios on thermal stability, flame retardancy, and mechanical properties were systematically investigated. The results demonstrated that PSNI and Kaolin exhibited a pronounced synergistic flame retardant effect. At a total loading of 10 wt% with a mass ratio of 1:1, the limiting oxygen index (LOI) of PC/5%PSNI/5%Kaolin increased to 43.7%, and the 1.6 mm thick specimen achieved a UL-94 V-0 rating. Compared with neat PC, the peak heat release rate (pHRR), peak smoke production rate (pSPR), total heat release (THR), and total smoke production (TSP) were reduced by 56%, 42%, 25%, and 57%, respectively. Through a synergistic mechanism involving chemical crosslinking/charring and physical barrier effects, PSNI and kaolin promoted the formation of a high-quality char layer, effectively suppressing the transfer of heat and smoke.关键词：Polycarbonate;Polysiloxane;Kaolin;Low heat and low smoke33|1|0更新时间：2026-07-07
- 摘要：Employing functionalized initiators is a key strategy for the efficient synthesis of end-functionalized polymers. Initiators containing protonic functional groups are often incompatible with the harsh conditions of anionic polymerization, leading to uncontrollable product structures. In this work, amino-protected dipeptides were used as biomass initiators to achieve one-step controlled synthesis of end-functionalized poly(ethylene/propylene oxide) in multiprotonic systems. Experimental results and theoretical calculations jointly demonstrated that polymerization occured exclusively from the carboxyl site of the dipeptide. The two-component Lewis pair organocatalyst exerted an acidity reversal effect between the alcohol hydroxyl group at the growing polyether chain end and the peptide amide on the initiator moiety, ensuring that the polyethers had controllable molar mass, low dispersity, and fully retained end-group dipeptide structures. This work broadens the applicability of the acidity reversal mechanism and site-selective anionic ring-opening polymerization method, laying the foundation for further expansion of biomass initiators and the construction of diverse biomass-polyether functional materials.关键词：Biobased polymer;Polymer functionalization;Ring-opening polymerization;Organocatalytic polymerization20|4|0更新时间：2026-07-06
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