最新刊期
卷 27 ， 期 9 ， 2014
- 摘要：Shape memory polymers (SMPs) are a class of stimuli responsive materials,which may recover their original shapes from large deformation upon the application of an external stimulus such as heat, electricity, alternating magnetic fields,light, water or chemicals, et al. They have been widely used in the fields of biomedical materials, aerospace, automobiles, textiles as smart materials. However, their development and applications are partly restricted by their low mechanical properties, such as low strength, elastic modulus,recovery forces and slow recovery rates. Incorporation of nanoparticles would contribute to the improvement of mechanical and shape memory properties of SMPs. Based on a fundamental understanding of the shape memory mechanism of SMPs, this paper aims to provide a review of shape memory polymer nanocomposites,including the purpose of the incorporation of nanoparticles, stimulus methods and mechanism, the interaction mechanism between nanoparticles and polymer matrix and their potential applications. Finally, the research trends of SMP nanocomposites are also summarized.关键词：Shape memory polymers (SMPs);Nanocomposites;Stimulus methods;Shape memory properties
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发布时间：2022-09-18 - 摘要：Energetic azide polymer binder has broad application prospects in the field of solid propellant, the synthetic methods and reaction mechanisms about azide energetic polymer binders were described; then properties and synthetic methods of homo-polymers and copolymers about 3,3-bis (azidomethyl) oxetane (BAMO)、glycidyl azide (GA)、3- azidomethyl-3-methyloxetane (AMMO) with azide group were reviewed in detail; finally,the development trend of azide energetic polymer binders are prospected.关键词：Energetic binder;Azide polymer;Research mechanism;Research progress
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发布时间：2022-09-18 - 摘要：Electrospinning technology is a simple and effective method to prepare nanofibers using polymer solution or melt. Cellulose acetate (CA) is used to replace the natural cellulose in the field of electrospinning,since it is easy to dissolve in organic solvents. This paper introduces the research and development of cellulose acetate composite nanofibers prepared by electrospinning in recent years at home and abroad,focusing on the CA/CNTs composite nanofibers, CA/metal particle composite nanofibers, CA/metal oxide composite nanofibers, CA based drug-loaded nanofibers, CA/PAN composite nanofibers, CA/PVA composite nanofibers,CA/CS composite nanofibers,and so on as well as theirs potential applications.关键词：Electrospinning;Cellulose acetate;Composite nanofibers
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发布时间：2022-09-18 - 摘要：Owing to the simple preparation process and varied preparation methods, the polymer-based super- hydrophobic materials are becoming the main bionic hydrophobic material gradually, bringing great convenience for industrial and agricultural production and people s daily lives. The research progress in the preparation technology of polymer-based super-hydrophobic materials was reviewed in this paper. And the preparation process and preparation methods at home and abroad of polymer-based super-hydrophobic materials are summarized, including the template method (biological template method, porous anodic alumina method and porous CO2 microspheres layer template method),chemical vapor deposition method, vapor-induced phase separation method,electro-spinning method,laser and plasma etching method and so on. In addition, we point out the big challenges that the super-hydrophobic materials will face in the future.关键词：Super-hydrophobic;Preparation method;Contact angle;Micro-nano composite structure
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发布时间：2022-09-18 - 摘要：Because of their unique molecular structure,superior thermal and mechanical properties,hyperbranched polymers have become a hot research topic in the area of polymer science and novel materials. Hyperbranched polyurea and poly(urethane urea) are derived from the research of polyurethane, which have some differences and similarities in their structure and properties. In this article, the synthesis routes and properties of hyperbranched polyurea and poly(urethane urea) were reviewed. The progress of their synthesis and application were discussed,including the applications on microcapsules, films and coating. In addition,the current issues and the prospects on the hyperbranched polyurea and poly (urethane urea) research were pointed out.关键词：Hyperbranched;Polyurea;Poly(urethane urea);Synthesis;Application
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发布时间：2022-09-18 - 摘要：Transdermal drug delivery system (TDDS) has attracted more and more attention due to its significant potential in avoiding the hepatic first-pass metabolism, maintaining a constant and prolonged drug level,and providing a local target and convenience for administration. However, the stratum corneum,namely the outermost layer of the skin, acts as a biological barrier, which would limit the transdermal delivery of drug molecules, especially the hydrophilic ones. For this reason, the development of effective methods to enhance the penetration of drugs through skin has become important. In recent years, as a kind of drug carrier for TDDS, the nanoparticle has become popular because of its excellent properties such as high entrapment efficiency, reduced enzymatic degradation,controlled release rate and large specific surface area which can easily accumulate on the surface of the skin to promote the penetration of the drug. This article mainly reviews the research progress in polymeric nanoparticles for TDDS, including the mechanism of enhanced penetration, the combination of nanoparticles and active penetration methods for TDDS. With reference to the problems existing in current studies,suggestions are also proposed.关键词：Transdermal drug delivery;Polymeric nanoparticles;Mechanism of enhanced penetration;Active penetration methods
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发布时间：2022-09-18 - 摘要：Conventional cationic polymerization proceeds only under the strict conditions of low temperature, anhydrous, anaerobic and the protection of high purity inert gas. It is ascribed to the high sensitivity to traces of water of commonly used Lewis acids, and even the presence of a small amount of water can make them invalid. Owing to the concept of "green chemistry" being put forward,water as an environmentally friendly green solvent has been highly appreciated by the industry. In recent years, with the development of water-tolerant initiating systems, cationic polymerization in aqueous media has emerged. It has changed the traditional concept of cationic polymerization, and this new polymerization technique has attracted much attention. This article first introduces the mechanism of cationic polymerization in aqueous media,then emphatically reviews the current research and evolution of cationic polymerization and their matching water-tolerant initiating systems of different monomers in aqueous media, simultaneously points out the advantages and disadvantages of various initiating systems. Finally, the problems existing in cationic polymerization in aqueous media are summed up,in the meantime the research orientations and development outlook are prospected.关键词：Cationic polymerization;Polymerization in aqueous media;Water-tolerant Lewis acid;Styrene
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发布时间：2022-09-18 - 摘要：Along with two major problems of the energy shortage and environmental pollution, people get further in the development and utilization of the solar energy. In the usage of the solar energy, solar cells are considered to be the most promising way. Meanwhile,the application of inorganic solar cells is limited because of the fatal weakness. Polymer solar cells (PSCs) have continuously drawn great interest in the photovoltaic field due to their several advantages, such as low cost,light weight, and easy combination and modification. In recent years, the power-conversion efficiencies of PSCs had already been more than 8%. In this article,how to design efficient PSCs was reviewed. Relations between materials and open-circuit voltage,short-circuit current density and fill factor of PSCs were discussed. At last, prospect of PSCs was expected.关键词：Polymer solar cells;Open-circuit voltage;Short-circuit current;Fill factor
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发布时间：2022-09-18 - 摘要：The "sliding graft copolymer" (SGC) was employed to toughen brittle polylactide (PLA) by melt blending. The SEM was characterized the phase structure of PLA/SGC blend. The toughening mechanism was investigated by the SEM photo of impact-fractured surface of PLA/SGC blend. The thermal properties and crystallization behavior of PLA/ SGC blend were investigated by DSC and XRD. It is found that the blends showed a typical "sea-island" morphology. The particle size is from 0. 8μm to 4. lμm. The elongation at break and notch impact strength has been increased 6 and 2 times respectively as compared to unmodified PLA, which indicating the toughening effect of SGC. The in vitro cytotoxicity tests showed that the cytotoxicity of PLA/SGC blends belonged to grade 1,indicating good cytocompatibility, thus can be applied in the biomedical field.关键词：Polylactide;Toughen;Sliding graft copolymer;Melt blending
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发布时间：2022-09-18 - 摘要：In this paper,the effect of the micro-block length of the micro-block associating polymer and the concentration of the sodium dodecyl sulfate (SDS) on the rheological properties of the polymer / surfactant system was studied. The results show that micro-block length has the greater impact on the viscosity of hydrophobically associating polymer solution. The associating polymer with longer block has the larger tendency to form the intermolecular association and the higher viscosity. As the addition of SDS, the viscosity of the polymer/surfactant system reaches an extremum in short term, then loweres and keeps at a stable value. The longer the block is, the larger the extreme viscosity is. With the increasing micro-block length, the polymer/SDS system also exhibits the stronger shear thickening property and the largerviscoelastic behavior. Comparing the variation trend of the plateau modulus (G0 ) of solution system with the one of terminal relaxation time (TR),we found that the micro-block length and the SDS concentration all have the greater impact on the physical crosslinking density of the the polymer/surfactant system and less impact on the physical crosslinking strength. These results provide an important insight into the underlying mechanism of the interactions between surfactants and the micro-block associating polymer.关键词：Micro-block hydrophobically associating polymer;Block length;Anionic surfactant;Rheological properties;The number of associations;Structural strength of association
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发布时间：2022-09-18 - 摘要：Copolymer solution which can be spun directly was prepared by low-temperature solution polycondensation using 2-chloro-p-phenylenediamine, terephthaloyl chloride (TPC) and 4, 4'-diaminodiphenyl ether (4,4'-ODA) in the solvent system of N-Methyl pyrrolidone/Lithium Chloride (NMP/LiCl). Precursor fibers were obtained by wet-spinning followed by washing and drying, and then the structure and mechanical property of the fibers were characterized by SEM and electronical tensile testing machine. The results indicated that spinning solution with high viscosity, high molecular weight and good stability can be obtained by copolycondensation. Furthermore, the fibers prepared by wet spinning possess high degree of orientation, high crystallization and good thermal performance.关键词：2-Chloro-p-phenylenediamine;4,4'-Diaminodiphenyl ether;Spinning solution;Wet spinning
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发布时间：2022-09-18 - 摘要：With the itaconic acid as dopant and ammonium persulphate as initiator, polyaniline (PANI) was synthesized under different temperatures by chemical oxidation polymerization. The productivity and conductivity of PANI were calculated and various performance indexes of PANI were measured. The electrical conductivity, chemical structure, UV- vis spectra and morphology of PANI were respectively characterized by the resistance test, Fourier transform infrared (FTIR) spectroscopy, UV-vis spectroscopy and scanning electron microprobe measurements. The results showed that the low reaction temperature was in favor of slowing the rate of chain termination to make the polymer chain longer and charge carrier transfer easier so that the conductivity of products were excellent but too high reaction temperature can break the chain of products because of oxidation so that the conductivity of products were low. When the reaction temperature of polymerization is 10 ℃,the PANI had the highest conductivity of 1. 29 × 10-2 (S• cm-1 ) and the highest productivity of 111. 2% and the microstructure of PANI was nanorod.关键词：Polyaniline (PANI);Itaconic acid;Reaction temperature;Microstructure;Conductivity
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发布时间：2022-09-18 - 摘要：Alginate was hydrophobically modified through a direct polycondensation of lactic acid grafting from sodium alginate. The results showed that nano particles with the diameters of 80~110nm were formed and uniformly distributed in the system. The nano particles were formed by hydrophobic interactions of polylactic acid segment. The modified alginate solution was dropped into calcium chloride solution to form microspheric beads. The release results showed that the newly prepared drug vehicle had enhanced drug loading rate and encapsulation efficiency, and it displayed slow release behavior. Drug release was fast in the weak alkaline solutions, but the release was nearly invisible in the acidic medium. The copolymer could be prepared as a pharmaceutical carrier for controlled release in the intestine.关键词：Sodium alginate;Lactic acid;Hydrophobic modification;Drug carrier
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发布时间：2022-09-18 - 摘要：Ion imprinting technology is an important branch of molecular imprinting technology. Ion-imprinted polymers have several outstanding advantages, such as predetermined recognition ability, relative easy and low cost preparation,high stability and excellent specific recognition ability for target ions. However, ion-imprinted polymers are difficult to separate from the solution. If ion imprinting technology is combined with magnetic technology, the prepared magnetic ion imprinted polymers not only have specific molecular recognition sites,but also have magnetic response characteristic,and can be separated and recovered easily under the extrinsic magnetic field. The research progress on magnetic ion imprinted polymer in recent years was reviewed in this paper. The problem and development trend in this area were also put forward.关键词：Magnetic ion imprinted polymer;Magnetic separation;Preparation
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发布时间：2022-09-18 - 摘要：Biomass materials show broad application prospects in many fields. Bio-based PTT fiber become the new hot spot for its excellent performance, environmental protection and sustainable development. In the paper, the research and production profile of 1,3-PDO at home and abroad are systematically introduced, and the energy advantages and technical bottlenecks of microbiological method are indicated. The research progress in aspects of bio-based PTT fiber preparation, structure and properties has been reviewed. Besides,the favorable situation to develop bio-based fibers and products is also illustrated. As biological 1,3-PDO technology is improving, the raw material cost, long hindered the development of PTT fiber, can be further reduced. It is well worth looking forward to rapidly develop bio-based PTT fiber.关键词：Biological;PTT fiber;1,3-PDO;eco-Textiles
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发布时间：2022-09-18 - 摘要：Polymer chemistry is a basic specialized course for the major of Material Science and Engineering, because it touches many scientific disciplines and is vital in fields such as plastics and synthetic fibers ; paints and adhesives; and even biomedical applications. Synthetic fiber and polymeric hollow fiber membrane are the characteristic researches of Tianjin Polytechnic University, which both require solid knowledge of polymer chemistry. Therefore,students' activity is important, beside teachers' efforts in curriculum planning and preparation. In order to promote students' self-learning, homework were elaborately designed and assigned to attract students' interests, improve teaching effectiveness and urge students to spend more attention on this course. Through different afterschool works, students can easily master basic disciplines, overcome difficulties and apply theories to practice. Investigation on junior students showed that various afterschool works were helpful for improving their study interests and scores.关键词：Polymer chemistry;Homework;Explore of teaching method;Self-learning
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发布时间：2022-09-18 - 摘要：Polymer structure is the basis of the performance of polymer. Polymer structure is also the starting point and basic knowledge for students to learn about polymer science. Polymer contains primary, secondary, tertiary and quaternary structures. Primary structure has the most important role in determining the structure of polymer. The diversity of secondary structure is an specific performance of polymer. Both primary and secondary structures determine the higher order structures and properties of polymer. In the lecturing of polymer physics, emphasis the fundamental role of polymer structure, use clear knowledge context of polymer structure, explain the decisive role of polymer structure on its properties supplemented with the structure of the polymer products with excellent performance which has been tested by the market. This can solid the students' understanding of the fundamental role of polymer structure. And it can achieve the purpose to explain the structure of polymer clearly.关键词：Polymer structure;Polymer physics;Polymer;Teaching
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发布时间：2022-09-18 - 摘要：This article is based on the full analysis of outside major students' knowledge structure and the knowledge hierarchy of polymer chemistry; it put forward a new method of efficiently completing outside major teaching task of polymer chemistry via using the experiment platform of polymer chemistry and the combining of education in classroom and practice in site. The teaching practice shows this method not only can help to deal with the contradiction of the little class hour and the most content course in outside major polymer chemistry course,but also make students tasted the important action of theory knowledge of polymer chemistry in daily life by practical teaching. Furthermore, the teaching method also reaches the incorporation of studying and using, theory and practice,class studying and outclass studying. The study achievement provides a new idea for efficiently completing outside major teaching task of polymer chemistry.关键词：University;Polymer chemistry;Teaching practice;Outside major
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发布时间：2022-09-18
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