最新刊期
卷 28 ， 期 8 ， 2015
- 摘要：Electrospinning technology is one of the most rapid and efficient method for the preparation of nanofiber, which has attracted extensive attention and has a great potential for application. In order to reveal the behaviors and mechanisms of jets during the electrospinning process,researchers focused on the jet theoretical models from the basic experiment of producing jets and had made a ton of research. This paper reviews the research progress of basic theory of electrosspinning jets from jet producing, motion regime of stable jet and jet instability. The mathematical and physical model equation of jets were introduced and the existing problems of electrospinning are discussed, which provide references for the further study of electrospinning jets theory and guidance of electrospinning process.关键词：Electrospinning;Nanofibers;Jets;Theoretical mode
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发布时间：2022-09-18 - 摘要：Stereocomplex polylactide (SC-PLA) can be formed by the packing of poly (L-lactide) and poly (D-lactide) chains side by side in a 31 helical conformation. Thanks to the dense packing and high physical interaction of the chains,the SC-PLA is featured by superior stability and melting point (ca. 50 ℃ higher than that of PLLA) as well as excellent thermal, mechanical and degradation properties. PLLA/PDLA blending is a common method for preparing SC-PLA, including solution blending,melt blending and microwave radiation blending and so on. During the forming process, the SC-PLA can be affected by the molecrlar weight, optical purity, mixing ratio of PLLA and PDLA and other factors. This review addresses the formation conditions and mechanisms, microstructures, properties and potential applications of the SC- PLA formed by blending PLLA with PDLA.关键词：Stereocomplex PLA;Blend;Structure;Properties
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发布时间：2022-09-18 - 摘要：Inspired by biological system which can heal its wound, the self-healing material that can detect the damage and heal itself automatically has developed. Because of simple preparation process, widely application field and extensive healing types, the microcapsule-based system has attracted most research attentions. Its repair process is triggered by rupture of microcapsule when a crack propagates through the matrix, followed by release healing agent into the crack plane. Then the healing agent mixes with catalyst, bonds the crack through polymerization. The healing chemistry that can transform from low viscosity liquid into tough and hard thermoset is the key to facilitate healing process. This review summarizes the different chemistries used in state-of-the-art self-healing materials based on microcapsule, and mainly describes ring-opening metathesis polymerization of cyclic olefin,ring-opening polymerization reaction of epoxide, further curing reaction based on solvent and click chemistry. Moreover, the click chemistry becomes a particularly powerful method to design self-healing material because of its simple and efficient feature,including azide-alkyne reaction, Diels-Alder reaction, thiol-ene reaction and thiol-isocyanate reaction. The mechanism of self-healing chemistries and influence factors of self-healing efficiency are analyzed, and the limitations and benefits of the healing chemistry are discussed. Finally the challenges and future opportunities are highlighted.关键词：Self-healing;Microcapsule;Healing chemistry;Ring-opening metathesis polymerization;Click chemistry
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发布时间：2022-09-18 - 摘要：The development of highly active and recoverable catalysts has been the subject of research in recent decades. A systematic introduction of techniques for preparing polymer fibers immobilized catalysts, and a brief description of the it' s application are discussed. Compared with conventional non-polymer fibers immobilized catalysts, polymer fibers immobilized catalysts can meet high specific surface area, easy processing, easy separation and so on, and therefore possess a high catalytic activity and excellent cycle performance. Advances in techniques for preparing polymer fibers and methods for immobilizing catalysts significantly promote the progress of high-performance immobilized catalysts with polymer fibers for the carriers, so that the catalysts will exhibit important significance in air purification, sewage treatment, large-scale chemical production and other fields.关键词：Polymer fibers;Immobilized catalyst;Catalyze
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发布时间：2022-09-18 - 摘要：The research on the antifouling mechanism has a guiding significance to the design and synthesis of the antifouling membrane materials. Zwitterionic polymer, as a new type of antifouling membrane materials, has been paid extensive attention. In this paper,the formation of membrane fouling and its influencing factors were thoroughly studied, and the antifouling mechanism and characteristics of the modified polymer separation membrane with zwitterionic group were expounded in detail. Meanwhile,the research progress of this type of separation membrane in recent years was also summarized according to various modification methods. Furthermore, the research of membrane antifouling mechanism and the further development of zwitterionic polymer separation membrane were predicted.关键词：Zwitterionic;Separation membrane;Membrane fouling;Mechanism;Modification
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发布时间：2022-09-18 - 摘要：The challenge of resource, energy and environmental crisis forces people to focus on environmental friendly materials. Due to the good mechanical performance, biodegradability and biocompatibility, microfibrillated cellulose (MFC) has attracted a worldwide attention. MFC can be blended with different polymer materials, resulting new composites with excellent performance. In this paper,the basic characteristics and properties of MFC are introduced. The recent progress in polymeric composites based on MFC has been reviewed. The polymer matrix is divided into synthetic polymer and natural polymer according to the source. The present paper review the structure and properties of composites of MFC blended with polylactic acid,polyvinyl alcohol,epoxy resin, starch, chitosan,natural rubber and so on.关键词：Microfibrillated cellulose;Composites;Structure;Properties
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发布时间：2022-09-18 - 摘要：Anion exchange membrane fuel cell (AEMFC) has been attracting extensive attention, for it has high energy desity, could use non-noble metal (such as nickel and silver) as catalyst, high catalyst stability and flexible fuel choice. Anion exchange membrane (AEM) is the key components of AEMFC. The commercial AEMs are not suitable for AEMFC applications, due to their low ion conductivity and poor stability. Thus develop AEM for AEMFC application became a hot research topic. In this review,we introduce the property of AEM for AEMFC application,functional method of AEM and summarize the research progress of AEM for AEMFC application.关键词：Fuel cell;Anion exchange membrane;Polymer electrolyte membrane
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发布时间：2022-09-18 - 摘要：In this paper, the molecular structure, characteristics, application of elasticity and the sources of gutta¬ percha were introduced. The structure of gutta-percha mainly consists of trans 1,4-polyisoprene with order crystal softness chains. The main features of gutta-percha were of good ageing resistance,lower dynamic heat generation, higher abrasion resistance,anti-fatigue as well as memory function. The gutta percha not only comes from the extraction of natural plant such as Eucommia ulmoides Oliver but from chemical synthesis (TPI). Overview of research progress on the gutta-percha or TPI modifying plastics, asphalt and preparing the memory material were included. In the paper, we also focus on the progress of technique of blending TPI or gutta-percha with polar and nopolar rubber. The prospects of the application of gutta-percha in the industry were carried out.关键词：Gutta-percha;Modification;Plastics;Rubber;Asphalt;Blend
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发布时间：2022-09-18 - 摘要：Poly(N-isopropylacrylamide-co-polyethylene glycol)-b-poly(L-glutamic acid-γ-benzyl ester) was synthesized by ring opening polymerization of N-carboxyl anhydride of γ-benzyl-L-glutamate (NCA) using the amino terminal macromolecule as an initiator. The y-benzyl ester groups in side chain were converted into hydrazide by hydrazine hydrate. Doxorubicin (DOX) was covalently loaded on the terpolymer, yielding nano micelles with DOX-loaded poly (L-glutamic hydrazide) as the core, and poly(N-isopropylacrylamide-co-poly ethylene glycol) as the hydrophilic shell. The micelles could be used as a drug carrier, showing temperature and pH dual responsive behaviors.关键词：L-glutamic acid;N-isopropylacrylamide;DOX;Micelles;Hydrazine
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发布时间：2022-09-18 - 摘要：In this paper, the effect of different concentrations of NaCl on rheological properties of the hydrophobic associating polymer/SDBS systems was studied. The results show that different NaCl concentration has vary on the role model of the polymer/surfactant systems,when at low NaCl concentration, the thickening amplitude is SDBS concentration of 0〜100mg/L,the maximum growth multiple of viscosity is 5. 665,and as the addition of NaCl, thickening amplitude increases; when the middle NaCl concentration, which viscosity-increasing section increases with increasing NaCl concentration,However, the magnitude of increase in viscosity rapidiyrapidly decline with increasing NaCl concentration, the biggest growth multiple is 3. 100; And high NaCl concentrations, the system is also found thickening, thickening zone widens by the addition of NaCl, viscosity stable value also increases. Rheological and fluorescence experiments further provide the influence of the interaction at different NaCl concentrations on the polymer/surfactant systems,addition of NaCl was found to enhances the polymer/surfactant systems interaction and promotes form mixing aggregates of the polymer/ surfactant; also found high concentrations of NaCl affect the SDBS solubility, thereby affecting the the polymer/surfactant systems interactions.关键词：Hydrophobic associative polymer;Dodecyl benzene sulfonate;Rheology;Fluorescence;Hydrophobic microdomains
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发布时间：2022-09-18 - 摘要：In this paper, the hybrid fibers of Poly (ε-caprolactone) (PCL)/rare earth (RE) were prepared by electrospinning, and the influence of RE addition,electrospinning voltage on the morphology, diametrer and thermal properties of the hybrid fibers was investigated by using SEM, XRD and DSC. The results show that, firstly, there are several PCL crystal structures in hybrid fibers,and many nano-pores occur in the surface of hybrid fibers by addition of RE. Secondly,with the increasing of voltage,or with the increasing of RE, the diameter of the hybrid fibers is decreasing firstly and then increasing, and the melting point of hybrid fibers goes up firstly and then down.关键词：Electrospinning;Hybrid fiber;Poly(ε-caprolactone);Rare earth;Melting temperature
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发布时间：2022-09-18 - 摘要：The disproportionately high and low molecular weight PEO blends were prepared by dissolving the two components in chloroform and then volatilizing the solvent. The cold crystallization of PEO and their blends were characterized by POM, XRD and AFM. The results show that PEO blends spherulites have birefringence. The reason is not the change of crystal type,but the thickness of the PEO lamellae are thin which crystallized during the heating process, while the lamellae are thick when crystallized at 20°C. It is the difference in lamellae thickness cause the brightness layered. The 200k PEO serve as nucleus,the 10k PEO play a role of solvent in blends. So the appearance ratio of big spherulites in blends is higher than the pure PEO. The radius of dark area increase as the ratio of 10k PEO increase in blends.关键词：Poly (ethylene oxide);Blend;Cold crystallization;Birefringence
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发布时间：2022-09-18 - 摘要：With the progress of science and technology, low-temperature environment is forcing people to enter the territory, and the thermal insulation material, which it is suitable for human body temperature,is the precondition into these areas. Stored energy and phase transition material with its unique energy storage and heat release mechanism have become a hot research topic in today's society. In this paper,the importance of stored energy and phase transition microcapsules, research status in domestic and foreign, were introduced. It was elaborated microcapsule formation process by the soft monomer butyl acrylate (BA) and hard monomer methyl methacrylate (MMA) as the wall material, and the influence of the monomers types on microcapsule morphology, Finally, the development trend of microcapsule and silicone rubber composites was previewed.关键词：Utra-low temperature;Phase transition;Microcapsules
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发布时间：2022-09-18 - 摘要：Polymer topologies include linear, cyclic, star-shaped, ladder-shaped, H-shaped, grafting, and hyperbranched. This article classifies various polymer topologies with illustration of every catalogue. The difference between cylindrical polymer brush and comb-like polymer is also involved. Some Chinese characters are easy to be confused when used in the terms of polymer science. For instance,three Chinese characters, "形" , "型" and "性" are similarly pronounced and sometimes incorrectly used in terms. Another typical example is "枝" and "支" .We intend to distinguish them in this article and correct inappropriate usage in textbooks and literatures. We encourage more teachers,researchers and students to pay attention to the discussion on correcting Chinese terms in polymer science. It will also benefit the development of polymer terminology.关键词：Polymer topologies;Polymer terms in Chinese;Polymer education
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发布时间：2022-09-18 - 摘要：Polymerization reaction engineering analysis is an important chapter in the course of " Polymer Reaction Engineering", the average degree of polymerization constitutes an important part of this chapter, the correct understanding of the involved concepts, essential meaning and physical significance of mathematical expressions is of very importance for learning polymer reaction engineering analysis which can help students to have a better understanding of such formulae. By extending the derivation of the number average molecular weight, the number average degree of polymerization have been deduced according to relationship of the average molecular weight, molecular weight of monomer and average degree polymerization. The Weight average degree of polymerization formula can be imitated. Furthermore, the instantaneous number average degree of polymerization and the instantaneous weight average polymerization degree have also been deduced and analyzed from the perspective of polymerization reaction engineering.关键词：Polymerization reaction engineering;Number average degree of polymerization;Weight average degree of polymerization
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发布时间：2022-09-18 - 摘要：The overall level of undergraduates' scientific research diathesis in local colleges is generally not high. It's an important way to achieve the talents cultivation objectives, by exploring how to improve the students' scientific research quality in practice teaching process. In this paper,take Chizhou University as an example, combining the author's teaching and research experience, suggested a number of specific measures to improve the undergraduate students'scientific research diathesis. Expected these measures can provide some references for the practice teaching, for some local regular undergraduate institutions' related specialty. The students' enthusiasm of participating in the experiment was stimulated, through beginning professional emotion education,restructuring and optimization of the experimental teaching contents. In the practice teaching process,emphasis on the experimental basis ability training, and offer some exploratory and comprehensive experimental projects. Using the new teaching mode that combined experiment course with research works, and accept undergraduates to participate in teachers' research works,while strengthening the teachers' instructor guiding role in the thesis teaching. The aim of the reformation is to cultivate and enhance the students' ability of practice and innovation,as well as the comprehensive characters.关键词：Experimental teaching;Talents cultivation;Ability training;Scientific research diathesis
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发布时间：2022-09-18 - 摘要：The function, characteristic and teaching contradiction of structure chemistry were discussed. By means of a living example,the way how to improve the teaching quality by the "knowledge-logic-structure and learning-in-mind-form" teaching method (abbreviation for "KM teaching method") was introduced: that is to design teaching proposal based on "knowledge logic structure", to develop and apply a kind of knowledge-logic-structure-showing courseware; and in the classroom teaching, should Stick to the teaching principles of "first to build a framework, then to fill and last to induce" and strengthen to teach knowledge structure, meanwhile combine with the "heuristic modes of teaching",thus the teaching problem of structure chemistry which is "high difficulty and capacity" should be solved effectively.关键词：Structure chemistry;KM teaching method;Knowledge logic structure;Courseware;Authorware program structure
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发布时间：2022-09-18
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