Polymer最新文献

Nowadays, single-ion conducting polymer electrolytes for high efficiency, stable, safe and dendrite-free Li-metal batteries are in great need to protect lithium metal anode. In this work, a boron-containing single-ion polymer electrolyte (BSPE), prepared by the copolymerization of allyl diglycol carbonate (ADC), lithium bis((trifluoromethyl)sulfonyl)amide (LiTFSI), and diisopropyl allylboronate (DPAB). The weak coordination interaction between Li⁺ and polar carbonate enhances Li⁺ transport ability. Further, the boron-containing cross-linker fixes the counter anions on the polymer backbones, limiting the movement of the anions and promoting the rapid and uniform Li⁺ transference. The BSPE with 3 wt% DPAB exhibits higher Li⁺ transference number (t₊ = 0.77) and better ionic conductivity (1.36 × 10⁻⁴ S cm⁻¹ at 25 °C) compared with that without DPAB. The wider electrochemical window (5.6 V vs. Li⁺/Li), stable polarization and suppressed lithium dendrites during the plating/stripping cycle at a current density of 0.2 mAcm⁻² for 600 h provide the metal-lithium batteries with better safety and higher efficiency. In addition, the initial discharge capacity of LiFePO₄/BSPE/Li is 140.7 mAh g⁻¹ with 95.2 % coulombic efficiency, and the capacity retention still remains 98.7 % after 200 cycles at 0.1C. The excellent performance endows the BSPE with the potential application in high-performance lithium metal batteries.

Poly (1,12-dodecylene 5,5′-isopropylidene-bis(ethyl 2-furoate)) has recently been introduced to the polymer field as an exceptionally flexible polyester derived from bio-based and cost-effective monomers. A partially sulfonated version of this polymer is prepared in this study by copolymerization with sulfonated isophthalic acid. A series of sulfonated bisfuranic-aromatic copolyesters PDDbF_XSI_Y, containing up to 50 mol% of sulfonated moieties was synthesized, for the first time, using the 1,12-dodecandiol as a comonomer. Their chemical structure was investigated by FTIR and NMR (¹H and ¹³C) spectroscopy. In terms of properties, these copolyesters showed high thermal stability (c.a. T_d,_max ≥ 350 °C), a low glass transition temperature and they were found to be amorphous up to 20 mol% of the sulfonated unit content. Hydrodegradability tests on PDDbF_XSI_Y films carried out under alkaline conditions revealed highly stable materials even with increasing amount of sulfonated units. In addition, the films exhibit good liquid water sorption, which increases as the amount of sulfonated groups decreases, following the opposite trend of previously reported sulfonated bisfuranic-aromatic copolyesters prepared using short-aliphatic chain diols. These properties are obviously related to the concurrently incorporation of a dodecylene chain and sulfonated groups in the same backbone, making it possible to generate new hydrolytically stable bisfuran-based polymers with a sorption feature.

In recent years, nanocomposite membranes have emerged as a focal point in the pervaporation process, garnering significant attention. The integration of various nanostructures into mixed matrix membranes has been extensively explored for their efficacy in enhancing separation capabilities by influencing membrane morphology. This review delves into the utilization of inorganic nanostructures, known for their superior properties and widespread availability, in pervaporation membrane applications. This study evaluates research endeavors employing these materials in pervaporation, scrutinizes outcomes, and identifies prevailing challenges. This comprehensive analysis aims to shed light on the potential and limitations of inorganic nanostructures in advancing pervaporation membrane technology. Furthermore, this review addresses challenges and future directions, aiming to guide researchers towards the development of next-generation MMMs for enhanced pervaporation applications.

Chemical cross-linking is commonly used to prevent slippage between molecular chains in shape memory polymers (SMPs) to improve shape return. However, chemical cross-linking makes SMPs less stretchable, and the disordered network structure reduces the ability of SMPs to maintain temporary shapes. To obtain ultra-high stretchability and better shape memory properties, a cyclic polymer (C-PTHF-OH) was introduced into the shape memory polyurethane (PUC_X) network, and the PUC_X network topology was controlled by adjusting the content of C-PTHF-OH molecular rings. PUC_0.5 exhibited the highest shape fixation (99.9 %) and shape recovery (98.4 %), and the higher the content of the C-PTHF-OH molecular ring, the higher the elongation at break of the prepared PUC_X, with a slight decrease in tensile strength. Compared to PUC₀ (2000 % elongation at break and 32 MPa tensile strength) prepared from the linear polymer, PUC_0.5 showed up to 2150 % elongation at break and 31 MPa tensile strength. This study provides new ideas for the design of network structures for SMPs and is a new paradigm introduced into the SMPs network by cyclic topological polymers.

In this work, lactose-based adhesive with excellent boiling water resistance was prepared by the Maillard reaction, free radical polymerisation and multiple cross-linking network strategy using lactose and biomass polyamino compound (MP) as raw materials. On the other hand, the branched P-N synergistic flame retardant coating was constructed using the developed MP reacted with aminotrimethylene phosphonic acid (ATMP), which was used to coat the surface layer of laminated composite to give it flame-retardant properties. The dry shear strength, 3 h hot water (63 °C) wet shear strength, and 3 h boiling water wet shear strength of the laminated composite were 2.23 MPa, 1.14 MPa, and 1.02 Mpa, respectively, which were in line with the requirements of GB/T 9846-2015 standard (≥0.7 MPa). In summary, this work provides potential methods for the preparation of environmentally friendly boiling water resistant lactose-based adhesive and branched P-N synergistic flame retardant coating which were used for the construction of high performance wood laminated composites.

Para-aramid nanofiber membranes (ANFMs) have gained significant attention owing to their excellent properties. However, the preparation of ANFM remains a challenge. The amount of entanglement in the ANF dispersion is insufficient, which is why the ANFM cannot be prepared directly through conventional spinning methods. Therefore, we proposed an airflow-assisted coaxial spinning (AFAS) method. A flexible polymer (polyethylene oxide (PEO)), was employed as the outer spinning solution for improving the spinnability of the precursor solution, thus facilitating the efficient preparation of a well-shaped ANFM. The AFAS method reported herein is effective for preparing para-aramid nanofibers and ANFMs. ANFM was successfully fabricated by AFAS, consisting of nanoscale superfine ANFs ranging from 20 to 25 nm, a small average pore size of 0.2 μm, and high porosity (exceeding 80 %). Additionally, the ANFM exhibits prominent mechanical properties (tensile strength = 88.3 MPa; Young's modulus: E = 1.5 GPa), good flexibility, an excellent flame retardancy and thermal stability (300 °C) and flame retardancy.

A series of novel carbonized polymer dots have been synthesized and characterized via the condensation reaction between curcumin and various amino acids with the assistance of microwave. More strikingly, both CPDs prepared from curcumin and L/D-aspartic acid can emit strong white light in aqueous solution and in doped polyvinylpyrrolidone. The white light emitting diodes based on L-Asp-CPD/PVP and D-Asp-CPD/PVP exhibit the CIE coordinates of (0.36, 0.34) and (0.38, 0.32) at the drive current of 0.12 A, CRI of 84.9 and 89.7, and CCT of 4385 K and 3410 K, respectively. The stability of LED derived from D-Asp-CPD was better than that from L-Asp-CPD at operational time of 5 h and the driven current of 0.02 A.

Mesophase pitch-based carbon fibers (MPCFs) exhibit high thermal conductivity (∼900Wm⁻¹K⁻¹) and are considered to be an important candidate for future thermal management. However, MPCFs lead to an increase in the electrical conductivity of nanocomposites due to the low volume electrical resistivity (∼10⁻³ Ω cm). The development of MPCFs nanocomposites with high thermal conductivity and good electrical insulation remains a challenging problem. In order to solve the problem, we utilized the surfactant cetyltrimethylammonium bromide (CTAB) as an anchor for hydrolysis, and employed a sol-gel method to deposit a silica coating on MPCFs (silica@MPCFs). Silica@MPCFs was used as the filler for polydimethylsiloxane (PDMS) matrix. The nanocomposites exhibit commendable thermal conductivity (achieving 1.52 Wm⁻¹K⁻¹) and excellent volume electrical insulation (exceeding 10¹³ Ω cm) at a 30 vol% concentration. Notably, both the thermal conductivity and volume electrical insulation exceed MPCFs/PDMS. This approach to electrical insulation treatment holds substantial potential for the future preparation of high-performance nanocomposites of electronic devices.

Hydrogen bonding, glass transition, water absorption, and plasticization are studied as a function of hydrogen bond donor concentration in the chain of a non-isocyanate polyhydroxyurethane system, synthesized by solvent-free aminolysis of a poly(ethylene oxide) (PEO) based cyclic carbonate. The concentration of hydrogen bond donors is controlled by varying the ratio of diaminobutane (DAB) and triethylenetetramine (TETA) in the amine component. Introduction of secondary amino groups enhances hydrogen bonding and rigidity of the chain, and, as a result, slows down dynamics, as evidenced by an increase in glass transition temperature. Hydroxyurethane groups are the primary hydration sites despite the hydrophilicity of the polyether. Secondary amino groups act as secondary hydration sites which further increases water sorption capacity. The Couchman-Karasz model describes excellently the dependence of glass transition temperature on composition in both dry and hydrated systems.

In this study, the monomer N–(ethyl–4–hydroxyphenyl)maleimide (TyHPMI) was synthesized from tyramine and maleic anhydride. Subsequently, free radical copolymerization was used to prepare the poly(S–alt–TyHPMI) alternating copolymer by reacting TyHPMI with styrene. We confirmed the chemical structure using Fourier transform infrared (FTIR), ¹H and ¹³C nuclear magnetic resonance (NMR). The sequence distribution of the poly(S–alt–TyHPMI) alternating copolymer was analyzed using mass–analyzed laser desorption ionization/time–of–flight (MALDI–TOF) mass spectrometry. Differential scanning calorimetry (DSC) measurements showed a single glass transition temperature (T_g) across various weight fractions of binary blended systems containing strong hydrogen–bonded acceptors, such as poly(S–alt–TyHPMI)/poly(4–vinyl pyridine) (P4VP) and poly(vinyl pyrrolidone) PVP, implying full miscibility. The T_g values predicted by kwei equation for the poly(S–alt–TyHPMI)/P4VP and poly(S–alt–TyHPMI)/PVP blends show a positive deviation from linearity. This deviation is due to the short alkyl chain reinforcing the addition of acidic TyHPMI units, which enhances intermolecular hydrogen bonding between the pyridyl or C=O groups and the OH units of the TyHPMI segment. As a result, FTIR spectral analyses indicate that the intermolecular hydrogen bonding between pyridyl and C=O groups is stronger in the poly(S–alt–TyHPMI) copolymer compared to the poly(S–alt–HPMI) copolymer. This is supported by the larger ratio of the inter/self-association equilibrium constant (K_A/K_B) value.