最新刊期
卷 26 ， 期 8 ， 2013
- 摘要：Atom transfer radical polymerization (ATRP) is one of the most extensively studied "living"/controlled radical polymerization (CRP) methods, not only owing to its simple, mild reaction conditions and broad applicability, but also it can be easily applied to produce polymeric materials with well-defined structure. In order to well understand and control the polymerization process, it is necessary to develop a comprehensive kinetic model for ATRP and coupling it with different reactor models, which can be useful for researchers to control over chain microstructure with predetermined molecular weight and narrow polydispersity, as well as copolymer composition and its composition distribution, and also optimize the polymerization conditions. This review illustrates the establishment of the appropriate ATRP kinetic model based on the theory of conventional free radical polymerization. Moreover, it also makes a comparison of the mechanism between "living"/controlled and conventional free radical polymerization examples in order to reveal the similarities and differences of the two methods within this field. In addition, we detail the research work concerning the kinetic modeling of ATRP, and more attention has been paid to analyze and summarize on the kinetic models from the point of different mathematical processing methods (method of moment, Monte Carlo simulation, and commercial software-PREDICI, GEPASI etc.).关键词：Atom transfer radical polymerization (ATRP);Kinetic model;Reactor model
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发布时间：2022-09-18 - 摘要：In this paper, basic principle of neutron reflectivity techniques, used in the oppositely charged polyelectrolyte/surfactant systems, was introduced. On the basis of introduction of the interfacial behavior and the surface tension curve of the weak interaction system, the effect of the polymer concentration, electrolyte and the chain length of surfactant on the surface tension were analyzed. According to the data determined by the neutron reflectivity and the existence of the surface tension peak, the interfacial behavior, the types of surface tension plots and theoretical model for oppositely charged polyelectrolyte/surfactant systems were pointed out.关键词：Oppositely charged polyelectrolyte/surfactant;Neutron reflectivity;Surface tension
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发布时间：2022-09-18 - 摘要：Chitosan is a natural polymer with amino and hydroxy groups. Hydrogels are cross-linked networks of hydrophilic polymers which can swell in water and retain large amounts of water without dissolving. "Intelligent" is a kind of characteristic that spontaneously responds to external stimuli. Chitosan-based intelligent hydrogels possess good biocompatibility and degradability which draws much attention of the researchers. The research progress of Chitosan-based intelligent hydrogels including pH sensitive, temperature sensitive and pH/temperature sensitive types were summarized in this article. The applications of the chitosan-based hydrogels in organization engineering and drug releasing were reviewed. Their future developments are discussed.关键词：Chitosan;Intelligent hydrogel;Tissue engineering;Drug releasing
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发布时间：2022-09-18 - 摘要：Silicon rubber and especially reinforced silicone rubber were widely applied in many aspects of industry because of its good tolerance, high resistance and wide temperature domain. Over the years, It was the pursuit of many researchers to reasonable explanation, simulation, prediction of silicon rubber material performance from the network structure of silicon rubber. The last decades of the relevant theoretical research were summarized in this article, which is based on the design of certain theoretical model on silicone rubber network structure to simulate and predict its performance simulation theory, focused on introduced meaningful classic simulation model and illustrated its basic hypothesis, applicable scope and limitation. Elaborated some new simulation results from molecular level and compared with the classic network model. In order to find a simulation method which have comprehensive simulation performance and feasibility.关键词：Silicone Rubber;Theoretical model;Application;Development
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发布时间：2022-09-18 - 摘要：The occurrence, development and pathological changes of animal connective tissue are closely related to their structures and morphologies, and particularly the orderliness on the structure of tissue is apparent, liquid crystalline structures of collagen in connective tissue are a transition state that collagen molecules self-assemble into collagen fibers or tissue. Based on reconstituted collagen molecules, we have discussed that triple helical structure has an impact on collagen molecules assembling into liquid crystal, and have analyzed research progress on structural transformation of collagen molecular liquid crystal and super-molecular liquid crystal, as well as thermal and dynamic forming conditions. Inducing the formation of collagen liquid crystal is the key to simulate construction of the extracellular matrix in vitro. It not only established contact for studying the mechanisms of connective tissue morphogenesis and pathological process, but also provided useful information for building tissue engineering scaffolds.关键词：Collagen molecules;Entropy induced order;Molecular liquid crystal;Super-molecular liquid crystal;Connective tissue
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发布时间：2022-09-18 - 摘要：Cellulose nanofibers combine in a very exciting manner important properties of cellulose with amazing features of nano-scale materials.While It’s difficult to prepare cellulose nanofibers by electrospinning directly because cellulose is seldom soluble in common solvents owing to considerable inter- and/or intra-molecular hydrogen bonding. However, it’s an effective method to prepare cellulose nanofibers using electrospun cellulose derivatives nanofiber followed by hydrolysis. This paper reviewes the development of preparing cellulose nanofibers through the two methods at home and abroad. The prospect of preparing cellulose nanofibers by electrospinning has also been described.关键词：Electrospinning;Cellulose;Nanofibers
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发布时间：2022-09-18 - 摘要：The synthesis of four new chiral liquid crystalline monomers (M1~M4) based on L-isoleucine derivative is described. The corresponding polymers (P1~P4) were prepared by graft polymerization of these monomers at dry toluene using chloroplatnic acid as a catalyst. The chemical structures of the obtained intermediate, chiral monomers and polymers were characterized by FT-IR and 1H-NMR. The average molecular weight was determined by gel permeation chromatography. The specific optical rotations were evaluated with a polarimeter. The experimental results showed that the specific optical rotations of M1~M4 were all right-handed, their values of specific rotation decreased with increasing rigidity. In addition, the monomers with near rigidity and same terminal groups, their specific rotation values hardly changed.关键词：L-Isoleucine;Liquid crystalline;Chiral monomer;Polymer;Synthesis
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发布时间：2022-09-18 - 摘要：A tri-arm block copolymer, polyethylene glycol/tetrahydrofuran copolyether, was synthesized with tri-arm polyethylene glycol and tetrahydrofuran as main raw materials and boron trifluoride ether as catalyst by means of cationic ring-opening polymerization in this research. The effects of some factors such as reaction time, raw material ratio, dosages of catalyst and ring-opening assistant on the hydroxyl value of synthesized block copolyether were examined through orthogonal test. The better synthesis condition for tri-arm block copolyether with higher molecular weight was obtained. The synthesized copolyether was characterized through infrared spectroscopy, gel permeation chromatography and nuclear magnetism resonance test.关键词：Tri-arm polyethylene glycol;Tetrahydrofuran;Star-shaped block copolyether;Cationic Ring-opening Polymerization
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发布时间：2022-09-18 - 摘要：A α-cyclodextrin (α-CD) modified poly(acrylic acid) (PAA-α-CD) acting as the host-polymer and an azobenzene-branched polyacrylamide (PAM-Azo) acting as the guest-polymer were prepared. The interaction of PAA-α-CD with PAM-Azo was characterized by 1H NMR and 2D NOESY NMR spectroscopy. The 2D NOESY NMR spectroscopy indicate that trans-azobenzene (trans-Azo) units are bounded strongly within the cavities of PAA-α-CD whereas the cis-azobenzene (cis-Azo) is not bound at all. A supramolecular inclusion complex, formed by PAA-α-CD and PAM-Azo, is accompanied by the formation of a light-responsive hydrogel. Upon photoirradiation with UV light of 365nm, the hydrogel is converted efficiently to the sol phase because the trans-Azo units are converted photochemically to their cis configuratons, where upon the resulting cis-Azo units dissociation from PAA-α-CD. The hydrogel can be recovered from the sol phase by photoirradiation with visible light of 430nm.关键词：Cyclodextrin polymer;Host-guest interaction;Supramolecular hydrogel;Light-responsive;Azobenzene
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发布时间：2022-09-18 - 摘要：As the deacetylated product of chitin, a polymer abundant in nature, chitosan has a range of outstanding properties such as biocompatibility, biodegradability, nontoxicity, film-forming ability, and bioactivities e.g. acesodyne, hemostatic, antibacterial, antiphlogistic and drug delivery properties. As a result, chitosan has a great potential for a wide range of applications in medicine, especially in preparing wound dressing film. This paper highlights the properties of chitosan in treating skin wounds, and the research progress of the wound dressing with excellent property prepared via chitosan and its derivates is reviewed.关键词：Chitosan;Derivates;Dressing film;Applications
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发布时间：2022-09-18 - 摘要：Polymer chemistry is a basic subject developed from organic chemistry and the synthesis reaction of the polymer is closely related to the synthesis reaction of the organic small molecules, especially the basic knowledge of organic chemistry have been applied largely in learning polymer synthesis reaction mechanism. So in polymer chemistry teaching, to use effectively organic chemistry knowledge is fairly critical to help students better understand and master relevant knowledge of polymer chemical reaction mechanism. According to my teaching practice, how to make use of organic chemistry knowledge to explain reaction activity and reaction mechanism in polymer chemistry have been discussed with several examples, such as the polymerization activity and mechanism of the vinyl monomer, the radical polymerization inhibitive mechanism, coordination polymerization mechanism.关键词：Connecting teaching;Polymer chemistry;Organic chemistry
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发布时间：2022-09-18 - 摘要：The bilingual teaching of Polymer Chemistry is significant in view of the trends in international development, the requirements of educational policy of Chinese government and the overall situation of polymer teaching. The precondition of bilingual teaching of Polymer Chemistry is elaborated detailedly. The problems encountered in foundational english, professional english and evaluation approach for the effectiveness of bilingual teaching in Polymer Chemistry are also discussed in detail based on the strategic consideration. Evidently, the strategic consideration is propitious to the synergetic development of all the academic courses, the improvement of bilingual teaching in Polymer Chemistry, especially the establishment and improvement of educational systems in training the outstanding experts with international sights in polymer science.关键词：Bilingual teaching;Polymer chemistry;Undergraduate
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发布时间：2022-09-18 - 摘要：Based on several typical exercises and analysis in the teaching of "Polymer Physics" as examples, it was illustrated in this paper that some essential issues are not to be ignored in applying the viscoelastic mechanical models to simulate the mechanical relaxation phenomena of polymers.关键词：Polymer;Mechanical model;Viscoelasticity;Mechanic relaxation phenomena
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发布时间：2022-09-18 - 摘要："Polymer chemistry" is a compulsory course for most chemical engineering specialty and materials specialty. How to show the engineering characteristics in the teaching process of polymer chemistry course has become the focus of attention. For the problem what is the engineering characteristics, the own viewpoints were advanced. Contraposing the problems how to embody the engineering characteristics in the teaching process, own exploration and attempts were introduced.关键词：Polymer chemistry;Teaching;Engineering characteristic
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发布时间：2022-09-18 - 摘要：Polymer chemistry course mainly introduces basic concepts, principles and basic methods of polymerization, and according to the mechanism, polymerization is divided into step polymerization, radical polymerization, radical copolymerization, ionic polymerization and coordination polymerization. To avoid too empty and abstract in the curriculum theory teaching, this paper uses the authors’ scientific research as an example, i.e., the synthesis process of lactic acid as raw material for preparing PLA(polylactic acid), combining with the basic principles of the polymerization reaction in the course of teaching, to discuss the reaction mechanism of linear condensation polymerization, cationic ring-opening polymerization, anionic ring-opening polymerization, coordination polymerization, etc. It integrates theory teaching, scientific research work and actual production together, to achieve a win-win of teaching and learning.关键词：Polymer chemistry;Theory teaching;Theory and practicing;Discussion
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发布时间：2022-09-18
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