最新刊期
卷 34 ， 期 5 ， 2021
- 摘要：Vanadium redox flow battery (VRFB) is a new type of electrochemical energy storage device with environmental friendly, long life, high safety and stable electrochemical performance. It is one of the current energy storage systems with great development potential. Electrodes and proton exchange membranes are key materials for VRFB and play decisive role in the electrochemical performance of the batteries. According to the differences in raw materials and structures of key materials. In this paper, the classification and characteristics of electrode and proton exchange membrane are described in detail, and the recent progress of the structure and functional modification of the two key materials as well as the composite and modification methods of different materials are summarized, and the future research emphasis and development direction are described.关键词：All-vanadium flow battery;Proton exchange membrane;Electrode;Research progress
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发布时间：2022-08-30 - 摘要：Butyl rubber, also known as isobutylene-isoprene rubber (IIR), is a synthetic elastomer produced by cationic copolymerization of isobutylene with around 0.6 to 2.5 percent isoprene in chlorocarbon solvents at low temperature. Butyl rubber has unique elastomeric properties that makes it a good choice for a wide variety of rubber goods. Its excellent impermeability to gas diffusion together with its flexibility makes it the ideal material for inner tubes of tires and other highpressure tubes. The isoprene provides the necessary unsaturation sites for crosslinking. Thus, improving the degree of unsaturation (Du%) of butyl rubber can enhance the vulcanization efficiency, and the bonding property between the butyl rubber and other kinds of rubber is improved, which will broaden the application of butyl rubber. In this review, we provide an overview of the research progress of the synthesis and preparation of high unsaturated butyl rubber. Four kinds of initiators, for instance, Lewis acids and organic halides, coordination complex consisting of cationic source derived from metallocene or organometallics and weak coordinate anions, alkyl halides of aluminum and chlorides of zinc alkyls, are summarized and elaborated in this review. Moreover, we prospect the development of high unsaturated butyl rubber. This review will undoubtedly act as a great reference and theoretical guidance for researchers engaged in synthesizing and preparing high unsaturated butyl rubber.关键词：Butyl rubber;Degree of unsaturation;Isobutene;Isoprene
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发布时间：2022-08-30 - 摘要：As one of the environmentally friendly fibers, the development of Lyocell fiber is based on the discovery of aqueous N-methylmorpholine-N-oxide (NMMO) solution as a good solvent for cellulose. Although at the early stage, the dissolution of cellulose in aqueous NMMO solution has been confirmed to be an entirely physical process by destroying the hydrogen bonds between cellulose macromolecules based on the dissolving phenomenon and experimental data, the understanding of the dissolving mechanism of cellulose in aqueous NMMO solution is still a long process. With the development of computer technology, the molecular simulation method has filled the field of weak interactions between cellulose molecule and solvent molecule, which makes the dissolution mechanism of cellulose get a new understanding, for example, the discovery of the amphiphilic of the solvent and cellulose molecules and the hydrophobic association interactions. The further understanding of cellulose dissolution mechanism can not only improve the stability of Lyocell process and solvent recovery efficiency, but also lay a theoretical foundation for the development of new solvents. In this paper, the dissolution mechanism of cellulose in aqueous NMMO solution is comprehensively summarized from the aspects of the cognition process of NMMO, experimental discovery and molecular simulation of the dissolution process.关键词：Cellulose;Lyocell;NMMO;Dissolution mechanism
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发布时间：2022-08-30 - 摘要：All-solid-state lithium-ion batteries have become the only way for the development of lithium-ion batteries in the future due to their advantages of high safety and high energy density. As the core component of all solid-state lithiumion batteries, polymer/inorganic composite solid electrolytes have many excellent properties of both inorganic solid electrolytes and solid polymer electrolytes, but they also face many challenges, including room temperature ion conductivity lower than 10-3S/cm and the interface impedance is large and so on. This article reviews the choice of polymer matrix for polymer/inorganic composite solid electrolytes, explores the types of inorganic fillers and their modification methods, and summarizes the preparation process of composite solid electrolyte membranes and prospects for its possible future development directions.关键词：lithium ion battery;Composite solid electrolyte;Inorganic filler;Ionic conductivity
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发布时间：2022-08-30 - 摘要：Petroleum-based polymers such as polystyrene are widely used for their light weight and excellent properties. However, the petroleum-based polymers are difficult to degrade in the natural environment and casue the issue of "white pollution" . Therefore, it is urgent to develop green and environmentally friendly polymeric foam to replace petroleum-based polymeric foam. Poly(lactic acid) (PLA) is a kind of green polymer made from renewable resources. PLA has good processing and mechanical properties, and foaming makes it with good sound absorption, heat insulation and cushion effect. It is an ideal bio-based polymer to replace petroleum polymer, and PLA can be used in packaging, architecture, tableware and tissue scaffolds. However, due to the low melt strength and slow crystallization rate of PLA, it is difficult to obtain PLA foam with uniform cell distribution and high expansion ratio. In this study, we review the research progress on improving the foaming behavior of PLA in recent years, including the preparation of PLA foam via different foaming technologies, modification methods of PLA foam, influencing factors of mechanical properties and its expanding application fields.关键词：Supercritical fluid;Polylactic acid;Foam
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发布时间：2022-08-30 - 摘要：Polyalcohol has the advantages of less damage to oil and gas reservoir, strong inhibition, good lubricity, low fluorescence level, no interference with logging, biodegradability, low toxicity and low price. It is applied in oil field drilling operation at home and abroad. In this paper, the research progress in inhibition, lubricity and flow pattern regulation of polyols at home and abroad is reviewed. The inhibition mechanism of polyols is mainly elaborated: cloud point theory, permeation theory and adsorption theory. The inhibition performance of polyols is well demonstrated by the three theories, but there are some limitations. In view of the problems in field application, the research status of hydrophobic modification, nano material modification and ionic liquid modification of polyols in recent years was introduced in detail, and its inhibition and stability were improved. At the same time, the development trend and application prospect of polyols in the future were also prospected.关键词：Polyol;drilling fluid;Inhibition;Lubrication;Research progress
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发布时间：2022-08-30 - 摘要：The alkali/urea compound solvents have excellent solubility for cellulose at low temperature, and provide a new method for the preparation of regenerated cellulose fibers. The novel preparation process of these fibers has the advantages of less production process, low production cost and cause no pollution to the environment, which has a broad development prospect. But the dissolution mechanism of cellulose in alkali/urea compound solvents at low temperature is complex, and has harsh solubility conditions, while cellulose has low solubility and stability, and the fiber strength remains to be improved. In this paper, the latest research progress of cellulose in alkali/urea compound solvents at low temperature is reviewed, and the dissolution mechanism is briefly introduced. Based on this, the future research trends and industrialization prospects of alkali/urea compound solvents are suggested.关键词：Cellulose;Alkali/urea compound solvents;Low temperature dissolution;Dissolution mechanism;Spinning
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发布时间：2022-08-30 - 摘要：Chitosan as natural polysaccharide chitin removal of acetyl products, because of their excellent physical and chemical properties and biological activities, become one of the most promising polymer in biomedical applications, as a result of chitosan in poor solubility in neutral and alkaline solution, its application is limited by a certain, Usually, chitosan is functionalized and modified to generate a series of chitosan derivatives. Chitosan derivatives can improve the water solubility, biological activity and mechanical properties of chitosan, so as to enhance its utilization value and expand its application field. Several functionalization methods of chitosan, including graft copolymerization, crosslinking, carboxymethylation, acylation and alkylation, were reviewed in this paper. The research progress of the application of modified chitosan as drug carrier was introduced in order to provide some theoretical basis for the study of modified chitosan.关键词：Chitosan;Functional modification;Drug carrier
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发布时间：2022-08-30 - 摘要：Polycaprolactone and hydroxyapatite powders were used as raw materials to prepare polymer threedimensional porous scaffolds by solvent casting/vacuum evaporation/particle leaching (SC/VV/PL). X-ray diffraction (XRD), scanning electron microscopy (SEM) and infrared analyzer (FT-IR) characterized the composition and microstructure of the scaffold. The related physical and chemical properties of the scaffold were studied. The results show that PCL/HA composite scaffolds with high porosity and good mechanical properties are successfully prepared. The pore size of PCL/HA composite scaffolds is between 100~300μm, the porosity has reached to 83%~89%, which is in line with the requirements of porous scaffolds. The requirements also show that the composite of HA can improve the crystallinity and mechanical strength of the scaffold, and the compressive strength reaches 3.6~5.1MPa.关键词：Polycaprolactone;Hydroxyapatite;Porous ceramic material;Mechanical strength
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发布时间：2022-08-30 - 摘要：Silicone rubber dielectric elastomer has attracted wide attention in the field of dielectric elastomer research due to its low modulus, fast strain response, high rebound rate, and wide temperature adaptability. They have very broad application prospects. However, it has the disadvantages of low dielectric constant and small amount of electric deformation. In response to this problem, this study uses silicone rubber as the matrix and carbon black as the filler. The carbon black/silicone rubber is prepared by controlling the variation range of the carbon black mass fraction within 0%~ 20% and the thickness variation within 0.5mm~2mm. Dielectric elastomer composite material, and test its mechanical and dielectric properties. The results show that adding carbon black filler to the silicone rubber matrix increases the dielectric constant and keeps the dielectric loss in a relatively low range by changing the mass fraction of the added carbon black. When controlling the thickness of the material, it is found that when the thickness is 1.5mm, the fracture strength of the composite material is relatively large, while the elastic modulus is relatively low, which is conducive to the deformation of the material.关键词：Silicone Rubber;Carbon black;Dielectric elastomer;Dielectric properties;Modulus
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发布时间：2022-08-30 - 摘要：Polymer chemistry experiments play an important role in the macromolecular curriculum system. Designing corresponding experimental courses based on the core scientific problems of polymer chemistry is not only conducive to students' solid grasp of the basic theory of polymer chemistry, but also conducive to the cultivation of innovative ability and scientific literacy. The core of collaborative polymer chemistry experiment system is introduced the variables (such as time, temperature, ratio of reactants, etc.) into the experimental contents, then students worked collaboratively to study the quantitative relationship between molecular weight of polymer and process parameters, with the help of the advanced and fast properties testing platform. Such changes benefit the students to master the basic skills and methods of polymer science research.关键词：Polymer chemistry experiment;Collaborative experiment system;Experiment reform;Determination of monomer reactivity ratio;Innovation ability
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发布时间：2022-08-30 - 摘要：Based on the perspective of engineering education accreditation certification, this paper analyzes the current situation and existing problems of experimental teaching in polymer materials and engineering majors, and proposes specific measures to reform experimental practice courses. Following the three core concepts of engineering certification (studentcentered, output-oriented, and continuous improvement) and focusing on the cultivation of students' ability to solve complex engineering problems, this major adjusts the course system and constructs a "chain" experimental course system to promote the seamless connection between theory and practice. The evaluation system of formative evaluation and resultoriented evaluation is established for the process evaluation of experimental practice curriculum implementation. By increasing the proportion of comprehensive and exploratory experiments and elaborately designing comprehensive polymer experiments, students' ability to solve complex engineering problems is improved.关键词：Engineering education accreditation certification;Polymer materials and engineering;experimental teaching;"chain" experimental course system
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发布时间：2022-08-30 - 摘要：In the course of polymerization reaction engineering, polymerization reaction rate directly affects the average polymerization degree of polymer, which is a core content of the course, and plays an important role in the textbook. Different polymerization mechanisms correspond to different polymerization rates, but they have a strong correlation. Taking the polymerization mechanism of free radical polymerization and condensation polymerization as the main line, the polymerization reaction rates of the two cases were compared and analyzed, and the similarities and differences between them were pointed out. Based on the polymerization rate, these issues are discussed in detail so that students understand and grasp the meaning of the polymerization rate.关键词：Radical polymerization;Polycondensatio;Polymerization mechanism;Polymerization reaction rate;Analyzed and discussed
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发布时间：2022-08-30 - 摘要：Under the new situation of Engineering education professional certification, taking the course of principle of polymer molding as an example, the moral elements of "socialist core values" are introduced into the professional curriculum, and the ideological and political education of professional courses is explored and practiced from the teaching content to teaching methods, and so on. The ideological and political courses will be organically integrated with the training objectives of polymer material talents, the engineering education professional certification, the development of local new materials industry and the orientation of management of Guiyang University. We should adhere to the combination of professional course knowledge imparting and value guidance, and guide students to set up college students' ideals and beliefs, value orientation, political belief and social responsibility while learning professional course knowledge, so as to cultivate new application-oriented engineering talents with both ability and integrity and all-round development.关键词：Engineering education professional certification;Ideological and political education in a course;Socialist core values;Reform
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发布时间：2022-08-30
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