最新刊期
卷 36 ， 期 12 ， 2023
- 摘要：Spiro[fluorene-9,9'-xanthene] (SFX) is one of the versatile molecular building blocks of organic/polymer semiconductors, which is widely applied in the construction of luminescent, charge transport and trapping materials in organic optoelectronics. In the early stage, SFX without any substituent could only be synthesized by multi-step o-halobiaryl method. In 2006, Wei Huang and Ling-hai Xie (Huang-Xie) fortuitously discovered the one-pot synthesis of SFXs, which effectively solved the problem of multisteped synthesisof building blocks in organic non-plane semiconductor, and further expanded the scope of substrates of azafluorene and aromatic amine compounds, finally coined as the "Huang-Xie method" of SFXs. This method has the advantages of simple steps, high yield and low cost, which is highly highlighted by chemists in MIT and named by Japanese scientists, and extensively adopted by the peers for the design of steric semiconductors. The industry has successfully achieved the mass production of SFXs by virtue of the high efficiency of the Huang-Xie method. Up to date, SFX has been widely exploited in academia and industry by replacing 9,9'-spirobifluorene (SBF), especially in the organic light-emitting diode (OLED) display technology from LG Company in South Korea.关键词：Organic semiconductors;Spiro[fluorene-9,9'-xanthene] (SFX);Huang-Xie method;OLED luminescent materials
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发布时间：2023-11-23 - 摘要：Solid lubrication can effectively reduce the friction coefficient and wear rate, and greatly prolong the service life of the substrate, so it has become one of the key technologies applied to the mechanical friction pairs of the moving parts at low speed, heavy load, and high or low temperature. Wherein, polymer solid lubrication techniques can be employed to substitute or coordinate fluid lubrication, where polymer powders, thin films, or composites are utilized to form low-friction lubricating coatings, leading to the avoidance of metal-to-metal contacts, reducing friction and wear. Four types of polymer solid lubricating materials (PSLMs), including bonded solid lubricating coating (BSLCs), solid stick lubricants (SSLs), solid lubricating pastes (SLPs) and self-lubricating composites (SLCs), are surveyed and systematized in this paper. The research status of waterborne bonded solid lubricating coatings with waterborne epoxy (WEP), waterborne polyurethane (WPU), and waterborne polyamide-imide (WPAI) as binder is emphatically discussed. Finally, the future development trend of solid lubricating materials was prospected, considering the current research and development status of solid lubricating materials and the shortcomings of solid lubrication technology applications in industrial fields.关键词：Solid lubrication;Polymer;Coating;Friction reduction;Wear resistant;Self-lubricating
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发布时间：2023-11-23 - 摘要：Traditional polymethyl methacrylate (PMMA) bone cement has been widely adopted in bone repair technics such as artificial joint replacement, percutaneous vertebroplasty and kyphoplasty, etc. However, PMMA bone cement is typically endowed with high polymeric heat, high monomer toxicity, poor osteoconductive and osteoinductive ability, weak bioactivity, and extremely high elastic modulus, which limit the clinical application prospects of PMMA bone cement. Therefore, the modification of PMMA bone cement, devoted to enhancing its mechanical properties, bioactivity and bone bonding capability, has become a hot topic in the field of bone tissue reconstruction. This paper will review the modification progress of PMMA bone cement and introduce the effective methods that improve the biological and mechanical properties of PMMA matrix, and discuss the future research direction of PMMA bone cement.关键词：Bone cement;Bioactivity;Elastic modulus;Osteoconductive;Osteoinductive
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发布时间：2023-11-23 - 摘要：Lithium-ion batteries have attracted extensive attention as a power source for portable electronic products, new energy vehicles, power storage equipment and other products. Lithium-ion batteries are composed of four parts: the anode (negative electrode), cathode (positive electrode), separator and electrolyte. Although the separator does not directly participate in the electrochemical reaction in lithium-ion batteries, as an important part of lithium-ion batteries, its properties greatly affect the performance of lithium-ion batteries. At present, polyolefin is still the most widely used and commercially successful separator material for lithium-ion battery, while because of its poor electrolyte wettability and thermal stability, the electrical properties and safety of lithium-ion batteries are reduced, so modification has become an important way to improve the performance and promotion of polyolefin separator materials. This paper summarizes the latest research progress on modification of polyolefin-based separators in the past five years through constructing of multilayer film method, surface coating technology and layer-by-layer self-assembly deposition technique. Finally, it is proposed that the thermal stability and electrochemical performance of polyolefin separators are still the key points of future research, and new separator materials are prospected.关键词：Polyolefin;Lithium-ion batteries;Separator
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发布时间：2023-11-23 - 摘要：Although the rapid development of electronic information technology has made our lives more convenient, they have also caused increasingly serious electromagnetic radiation pollution. In order to completely eliminate electromagnetic radiation pollution, electromagnetic shielding materials with low reflectivity and high absorption rates are increasingly being favored by researchers. For the above reasons, this paper analyzes the design concept of polymer-based electromagnetic shielding materials doped with magnetic fillers based on the electromagnetic shielding mechanism. And it also summarizes the preparation of magnetic metal/polymer shielding materials, magnetic filler/metal/polymer shielding materials, magnetic filler/MXene/polymer shielding materials, magnetic filler/carbon/polymer shielding materials and magnetic materials/conductive polymer shielding materials, respectively. The intrinsic link between material structure and shielding effectiveness and reflection loss is discussed in detail. In conclusion, the key challenges, potential applications and prospects for the development of such materials are presented.关键词：Polymer;Electromagnetic shielding;Magnetic fillers;Low reflection
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发布时间：2023-11-23 - 摘要：The copolymerization of ethylene oxide (EO), glycol methyl glycidyl ether (nGE) and allyl glycidyl ether (AGE) catalyzed by i-Bu3Al/H3PO4/DBU has been examined. The microstructures, thermal properties and molecular weights of the obtained polymers were characterized by nuclear magnetic resonance spectroscopy (NMR), gel permeation chromatography (GPC) and differential scanning calorimeter (DSC). The results showed that the i-Bu3Al/H3PO4/DBU catalyst serves as an excellent catalyst for the copolymerization of EO, nGE, and AGE to afford a family of ether chain modified poly(ethylene oxide). The obtained EO-nGE copolymers and EO-nGE-AGE terpolymers with controllable contents were conveniently obtained in 100% yield within 30 min by changing the feed ratio. The ether chain length of nGE has no effect on the copolymerization. The cross-linked copolymers were prepared using the EO-nGE-AGE terpolymer as precursors and 1,2-ethanedithiol as a crosslinking agent. The properties of copolymers revealed that the ether chain length and content, crosslinking had a significant impact on the conductivity and mechanical properties of copolymers. The copolymers with tetraethylene glycol methyl glycidyl ether (4GE) as a comonomer exhibited higher conductivity than that of diethylene glycol methyl glycidyl ether (2GE). With the increase of the content of 4GE in the EO-4GE copolymers, the conductivity increased, but the mechanical properties decreased. The appropriate crosslinking degree improved not only the mechanical properties but also conductivity. The cross-linked EO-4GE-AGE polymer electrolytes containing 39 mol% 4GE and 2 mol% AGE showed the tensile strength and conductivity of 1.41 MPa and 9×10-5 S·cm-1 at 30 ℃, respectively.关键词：Poly(ethylene oxide);Solid polymer electrolyte;Lithium battery
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发布时间：2023-11-23 - 摘要：A novel 1,3-disubstitued indolyl ligand was designed and synthesized, and furtherly, a series of corresponding rare-earth metal complexes were obtained. The complexes were characterized by X-ray single crystal diffraction, nuclear magnetic resonance (NMR) spectroscopy, Fourier transform infrared (FTIR) spectroscopy as well as elemental analysis. The results indicated that the ligand coordinated to the metal in NCN tridentate mode to form a mononuclear penta-coordination geometry, adding two alkyl groups. The complexes could efficiently catalyze the isoprene polymerization with AlMe3 and [Ph3C][B(C6F5)4] as co-catalysts to obtain 1,4-cis polymer.关键词：Rare-earth metal alkyl complexes;1,3-Disubstiututed indole;Isoprene;Polymerization
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发布时间：2023-11-23 - 摘要：Liquid chromatography fractionation technique is a typical characterization method for efficiently determining the fine structure of polyolefin resins, which have complex chemical composition distribution and chain structures. Compared with the widely used crystallization-based fractionation techniques, high temperature-temperature gradient interaction chromatography (HT-TGIC), as a novel fractionation method, holds great advantages in analyzing amorphous polyolefins, thus broadening the application of fractionation techniques in polyolefin resins. In this paper, typical applications of HT-TGIC in the polyolefin characterization were demonstrated, especially for low crystallinity/amorphous polyolefin resins that are limited by crystallization fractionation techniques. And more information about bivariate chain structures of polyolefin could be revealed by TGIC coupled with GPC technology. This could provide support and guidance for the development and design of new polyolefin materials with excellent performance.关键词：Polyolefins;Chemical composition distribution;Thermal gradient interaction chromatography;Fractionation;Adsorption
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发布时间：2023-11-23 - 摘要：Industrial ethylene-vinyl alcohol copolymer (EVOH) is mainly prepared by alcoholysis of ethylenevinyl acetate copolymer (EVA) up to now. However, a large amount of wastewater will be produced during the preparation of EVOH, which inevitably results in a series of environmental problems. Herein, a series of alkaline deep eutectic solvents (DESs) were synthesized and used as eco-friendly catalysts for alcoholysis of EVA copolymer. The structure and catalytic performance relationship of DESs and the effects of the reaction parameters, EVA composition, and nitrogen flow on the alcoholysis were systematically investigated. The DESs with higher basicity were more efficient for the methanolysis of EVA, and among them, 1,8-diazabicyclo[5.4.0]undec-7-ene/benzylalcohol (DBU-BA) exhibited excellent catalytic activity and afforded EVOH with nearly 100% of alcoholysis degree at very low catalyst loadings. Moreover, DBU-BA could be reused at least five times without the decrease of catalytic activity, showing excellent reusability. On the basis of proton nuclear magnetic resonance (1H-NMR) and Fourier transform infrared spectroscopy (FTIR) analyses, the plausible mechanism of DESs catalyzed alcoholysis of EVA was proposed.关键词：Ethylene-vinyl alcohol copolymer;Deep eutectic solvents;Alcoholysis;Catalysis;Reusability
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发布时间：2023-11-23 - 摘要：Copolymers with varying molar ratios were created by initiating hydroxyethyl acrylate and maleic anhydride monomers with ammonium persulfate. A capillary dilatometer was used to measure the conversion of copolymerization. The copolymer’s composition curve was determined using acid-base titration, and the reactivity ratios of hydroxyethyl acrylate to maleic anhydride were determined using the YBR method. According to the calculation results, r1(HEA) and r2(MA) were 2.3188 and 0.0272, respectively, indicating that hydroxyethyl acrylate should be slowly added to maleic anhydride in order to obtain a uniform copolymer. Finally, it can be obtained by potentiometric titration, the pKa1 and pKa2 values of copolymer with the molar feed ratio of 7∶3 are 4.33 and 7.59, respectively.关键词：Maleic anhydride;Hydroxyethyl acrylate;Copolymerization;Reactivity ratio;pKa
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发布时间：2023-11-23 - 摘要：Environmentally friendly and highly absorbent resin (P(AA-g-Aloe)) was synthesized by grafting copolymerization of Aloe and acrylic acid (AA). The structure and morphology of the superabsorbent resin were charicterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The effects of different synthetic conditions on the water absorption (salt) of the highly absorbent resin (distilled water 1194.2 g/g, tap water 339.8 g/g, 0.9 wt% NaCl 103.3 g/g) were investigated. Meanwhile, the swelling property was the best when pH=7, and the swelling rate was 70.8% after five times of repeated swelling, the water retention rate reached 31.67% after 12 h at 80 ℃. The Aloe-based superabsorbent resin can be applied to water retention and sand fixation in arid desert areas, agriculture and forestry horticulture, water retention in agricultural planting and so on.关键词：Superabsorbent resin;Aloe;Water-absorbing quality;Biomass;Environmentally friendly
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发布时间：2023-11-23 - 摘要：The rheology and crystallization behavior of thermal liquid crystalline polymer (TLCP) resin with monomer ratio of hydroxybenzoic acid (HBA)∶6-hydroxy-2-naphthoic acid (HNA)=73∶27 is investigated in this study. The effects of parameters including dynamic shear frequency, shear rate, temperature and time on the linear and nonlinear rheological behavior are firstly discussed. It is pointed out that the intrinsic rigid characteristic of TLCP molecule is the main reason for the solid-like behavior at low frequency range and the failure of Cox-merz rule. Then the isothermal and nonisothermal crystallization behavior of TLCP is investigated based on rheology measurement characterizations. It shows that the crystallization rate decreases significantly as the cooling rate declines from 10 ℃/min to 1.5 ℃/min for TLCP resin from nematic phase. In addition, the isothermal crystallization behavior of TLCP melt is controlled by homogeneous nucleation and the corresponding crystal growth is in a three dimensional way with an Avrami point value of around 4. Moreover, it is found that increasing the molecular weight of TLCP resin contributes to decreasing the crystallization ability but has no influence on the crystallization way. This report confirms that it is an effective tool to study the mechanism of TLCP crystallization behavior by monitoring the rheology behavior of TLCP resin during cooling process.关键词：Thermal liquid crystalline polymer;rheology behavior;nonisothermal cyrallization behavior;isothermal cyrallization behavior
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发布时间：2023-11-23 - 摘要：Poly(acrylic acid) (PAA) and graphene oxide-chitosan (GO-CS) composites were deposited on the surface of polypropylene (PP) microporous membrane to prepare poly(acrylic acid)/graphene oxide-chitosan (PAA/GO-CS)n composite membrane by layer-by-layer assembly technology. The adsorption and separation effect of (PAA/GO-CS)n composite membrane for methylene blue and congo red in aqueous solution was investigated. The structures of GO-CS complex and (PAA/GO-CS)n composite membrane were characterized by infrared spectroscopy, thermogravimetric analysis and scanning electron microscope. Results show that (PAA/GO-CS)n composite membrane was successfully prepared and had stable thermochemical properties. The surface morphology and porosity of the composite membrane can be controlled by the number of assembled layers. The permeability of the composite membrane to methylene blue and congo red decreased with the increase of the number of assembled layers, and the interception rate increased with the increase of the number of assembled layers. The permeability of the composite membrane for methylene blue was 2761.3 L·m-2·h-1·bar-1, the retention rate was 91%, the adsorption rate was 39%. The permeability for congo red was 3068 L·m-2·h-1·bar-1, the retention rate was 43%, the adsorption rate was 33% when assembled to 20 layers. The composite film has preferential adsorption for positively charged cationic dyes.关键词：Graphene oxide;Chitosan;Composite membranes;Adsorption and separation;Dye
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发布时间：2023-11-23 - 摘要：Philosophy and science are inseparable and complement each other,which is also true in polymer science. In decades of polymer physics teaching, we deeply realize that the philosophical thinkings are profuse with many examples. The "quantitative change to qualitative change" is mainly dealt in the manufacture about teaching research in order to make the students realize the importance of studying philosophy in the developing of polymer physics.关键词：Polymer physics;quantitative change to qualitative change;Flexibility;distribution of degree of crystallinity
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发布时间：2023-11-23 - 摘要：Polymer Physics is a subject that studies the internal relationship and laws between polymer structure and performance, and is the core course of materials, chemistry and chemical engineering majors. It aims to cultivate the ability to analyze and solve polymer related problems with correct physical thinking, and provide an important discipline basis for future professional development. Polymers are significantly different from small molecules, and have multi-scale characteristics in different spaces and energies. The autonomous learning ability, high-level thinking ability and innovation awareness are weak in the class. In view of the "pain point" problems in the teaching of this course, we cultivate high-quality talents with original ability. We focus on the development of students, promote the "deep integration of science and education" teaching mode, and use scientific research projects to lead the whole processes of the Polymer Physics class, which enables students to conduct whole-hearted learning in the process of the class and achieve the combination of learning and thinking, and the integration of "knowledge, ability and quality". By this way, the creative ability of undergraduates in the field of basic polymer researches has been greatly enhanced.关键词：Polymer physics;Deep science and education integration;Education integration
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发布时间：2023-11-23 - 摘要：In order to promote the in-depth construction of the first-class major, the material chemistry major of Liaoning Petrochemical University has focused on the direction of polymer chemical engineering and carried out a series of adjustments and reforms in four major modules, including the construction of theoretical courses, the coordination of experimental and theoretical teaching, the exploration of course-embedded ideological education, and the combination of science and technology competitions with graduation designs. These efforts have laid a solid foundation for cultivating applied engineering and technical talents in the field of polymer chemical engineering in the face of new situations.关键词：Polymer chemical engineering;First-class major;Material chemistry
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发布时间：2023-11-23
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