最新刊期
卷 34 ， 期 10 ， 2021
- 摘要：Montmorillonite (MMT) is a natural mineral resource with huge reserves and low price. It has a unique lamellar structure and is a cost-effective filler to enhance the performance of polymer materials. When MMT is well dispersed in polymer matrix, it can obviously improve the mechanical properties, gas barrier properties, thermal stability and flame retardancy of polymer materials. However, it is difficult to get good dispersion in polymer matrix because the hydrophilicity of its surface leads to poor compatibility with polymers. Therefore, it must be organically modified. Based on the structure and modification mechanism of MMT, the types of organic modifier and research progress in organic modification MMT at home and abroad in recent years were summarized.关键词：Montmorillonite;Organic modification;Nanocomposites;Polymer
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发布时间：2022-08-30 - 摘要：g-C3N4 is widely used as a promising star semiconductor photocatalyst because of its good stability, strong catalytic performance, low cost, non-toxic and other advantages. The potential value in the fields of energy, catalysis and sensing has been continuously exploited, and important achievements have been made in the fields of chemistry, materials, physics, biology, environment and energy. In order to improve its quantum efficiency and photocatalytic activity, g-C3N4 with different morphologies and doping elements was synthesized and great progress was made. In this paper, based on introducing g-C3N4 photocatalytic mechanism, the methods for the synthesis of g-C3N4 nanosheets were summarized in details. Then, some methods for improving the photocatalytic activity of g-C3N4 were summarized. Finally, the development prospects of g-C3N4 in the aspects of controllable morphology, industrial production and environmental restoration are prospected.关键词：g-C3N4 Nanosheets;Synthesis;Modification;Photocatalytic activity
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发布时间：2022-08-30 - 摘要：Polyethylene pipe resins are widely used in gas or water transportation pipes, and slow crack growth (SCG) performance is an important index for evaluating the quality of resins, and it is also an important basis for accurately predicting the service lifetime of pipelines. This article summarizes the structural factors of polyethylene pipe resin, including the influence of molecular weight and its distribution, comonomer content and its distribution, number of tie molecules, and lamella thickness on the slow crack growth behavior. Generally, increasing the molecular weight and its distribution, and the comonomer content are all effective to improve the slow crack growth resistance. The number of tie molecules and the lamella thickness are affected by the molecular weight and its distribution, the comonomer content and its distribution. By summarizing the recent research progress, it tries to provide some suggestion to industry in improving the performance of slow crack growth resistance. It also looks forward to the future development trend of the research on the influence of structural factors on the slow crack growth of polyethylene pipes.关键词：Polyethylene pipe;Slow crack growth;Structural factor;Molecular weight and molecular weight distribution;Tie molecule
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发布时间：2022-08-30 - 摘要：Thermosensitive materials can respond to the change of temperature, which is a research focus of stimuliresponsive materials. As a kind of biodegradable polyester with good biocompatibility, poly(lacic acid) (PLA) is widely used in biomedical materials, but its poor hydrophilicity and lack of reactive functional groups in the main chain limit its further application in many areas such as drug control release. By means of functional modification, PLA can be endowed with thermosensitivity, and the obtained thermosensitive PLA-based material can have the excellent properties of both types of materials. At present, the preparation of thermosensitive PLA materials is mostly based on the ring-opening polymerization, combining with other synthesis strategies such as reversible addition-fragmentation chain transfer polymerization, living cationic polymerization and click chemistry. In this paper, the preparation and application of thermosensitive PLA materials in recent years are reviewed according to the classification of the polymers involved in the modification. Development of multi-responsive polymers based on thermosensitive PLA materials and the simplification of preparation methods of related materials will be important.关键词：Poly(lactic acid);Thermosensitive;Stimuli-responsive materials
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发布时间：2022-08-30 - 摘要：Magnetorheological fluid is composed of magnetic particles, carrier fluid and additives. Numerical simulation is a new method that for the past few years to study the micro mechanism of MR fluid, which can establish the theoretical model of the magnetic particles of MR fluid and analyze and calculate the properties of MR fluid.In this paper, we introduce the previous model of magnetorheological fluid magnetic particles by using various numerical simulation methods and verify the effectiveness of the model through experiments.The numerical simulation methods of MR fluid include lattice Boltzmann method, Monte Carlo method, dynamic simulation method and stress tensor based on Maxwell are introduced. The principle of each numerical simulation method is introduced and its advantages and disadvantages are analyzed.Finally, the application of these numerical simulation methods in magnetorheological fluid is introduced.关键词：Magnetorheological fluids;Composition;Numerical simulation;Methodological principles
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发布时间：2022-08-30 - 摘要：Using C4, C8, C18, NH2-modified macroporous silica gel and pure macroporous silica gel as substrates, five cellulose tris(4-methylbenzoate) (CTMB) chiral stationary phases for high performance liqiud chromatography were prepared. With four mobile phases, ibuprofen, mandelic acid, DNB-leucine, ketoprofen and flurbiprofen were resolved on those chiral columns. The experimental results confirm that five chiral drugs have different degrees of resolution on five chiral columns. CTMB coated on aminated macroporous silica gel and pure macroporous silica gel usually has a good resolution. This research provides a way for the actual resolution of five chiral drugs.关键词：Chiral drugs;Cellulose tris(4-methylbenzoate);Chromatography;Enantiomeric resolution
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发布时间：2022-08-30 - 摘要：In this paper, the photoactivity of tung oil-based urushiol analogues (CAT-ME) and its application in UV curing system were discussed. By comparing the curing conditions of tung oil-based urushiol analogs at room temperature (28℃), heating (80℃), and UV light (2.5kW), the curing activity was investigated, and the effects of photoinitiators, functional monomers and tung oil-based urushiol analogs on the UV curing system were also studyed. The results showed that tung oil-based urushiol analogs (CAT-ME) could not be solidified into a completed film, due to lacking of biological enzyme, a main component in raw lacquer. PI-819 was the best photoinitiator. Multifunctional monomer was beneficial to increase the tensile strength of the film, while monofunctional monomer was helpful to increase the elongation at break, and the optimum proportion of HEMA∶HDDA was 10∶10~14∶6. The optimal proportion of CAT-ME was 5%~15%. In addition, the UV-cured films mixed with 15% CAT-ME possessed excellent mechanical property and thermal stability, and the gel fraction reached 99.5%, the tensile strength was up to 25.07MPa while the breaking elongation increased by 4.57%, and SEM displayed that the surface of the film was relatively smooth and flat.关键词：Tung oil;Urushiol analogues;UV curing;Activity;Photoinitiators
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发布时间：2022-08-30 - 摘要：The low molecular weight fractions and volatile components of the trans-butadiene-co-isoprene copolymer rubber (TBIR), which synthesized by using the MgCl2 supported TiCl4 catalyst system, are collected by using constant temperature solvent fractionation and variable temperature gas phase collection methods. The collected components are characterized by 1H nuclear magnetic resonance (1H-NMR), gel permeation chromatography (GPC) and gas chromatography/mass spectrometry (GC-MS). The results show that the content of ether soluble fraction is about 50% (wt). The ether soluble fraction is composed of high trans-butadiene-co-isoprene copolymers with lower molecular weight and a small amount of butadiene-isoprene dimer and oligomer. The content of acetone soluble component is about 7.6% (wt). The acetone soluble component is composed of isoprene-butadiene dimers and/or copolymers with the weight average molecular weight about several hundreds. The as-obtained copolymers and dimmers may generate during the copolymerization process by the triisobutyl aluminium cocatalyst. The volatile component obtained by the low temperature gas phase collection is mainly isoprene monomer residual in TBIR. With the increasing of the gas phase collection temperature, there appears butadiene-isoprene dimer and the content of butadiene-isoprene dimer increases as while as the content of isoprene in the volatile component decreases.关键词：trans-Butadiene-co-isoprene copolymer rubber;Solvent fractionation;Volatile;GC-MS;Oligomer
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发布时间：2022-08-30 - 摘要：To obtain electrospun PLLA fibrous membrane with high filtration efficiency and low filtration resistance in mass production, the rheological behavior and surface tension of PLLA solution prepared by dichloromethane (DCM), 1,1, 1,3,3,3-hexafluoro-2-propanol (HFIP) and DCM/DMF mixed solvents with different volume ratios were studied by means of rotary rheometer and optical video contact angle meter. The effects of solvent type and content on the spinnability of PLLA solution and the microstructure, filtration performance of the electrospun fibrous membrane were studied by SEM and filtration efficiency tester. Under the same concentration, the flow behavior of PLLA solution prepared by HFIP was pseudoplastic Bingham body, and the viscosity is higher than that of PLLA solution prepared by DCM, resulting in a better spinnability of PLLA solution, finer fibers. The filtration efficiency and resistance of this fibrous membrane were 9.923% and 534.4Pa higher than those of prepared by PLLA solution with DCM as solvent, respectively, in the same spinning time. When DCM or DCM/DMF was used as solvent, the flow behavior of PLLA solution was pseudoplastic. The stability and spinnability of PLLA solution prepared by the DMF/DCM mixed solvent were obviously improved than the PLLA solution prepared with only DCM as solvent, resulting in the finer fibers and the similar filtration efficiency, 224.2Pa lower filtration resistance of fibrous membrane than those of prepared by PLLA solution with HFIP as solvent in the same spinning time.关键词：Polylactic acid;Rheological behavior;Electrospun fibrous structure;Filtration efficiency;Filtration resistance
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发布时间：2022-08-30 - 摘要：The compatibility of polymer blends directly determines the phase structure and properties of the composites. The study of compatibility is the basis of polymer blending modification. In this paper, five common rheological methods for characterizing the compatibility of polymer blends are introduced, i.e., the glass transition temperature method, the low-frequency slope method, the Cole-Cole curve method, the time-temperature equivalence principle method and the creeprecovery method. The rheological methods have many advantages, such as convenience sample preparation, less impact on samples, good applicability and high sensitivity, which are poweful means to characterize the compatibility of polymer blends.关键词：Rheological;Compatibility;Blends
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发布时间：2022-08-30 - 摘要：Under the background of the state vigorously promoting the construction of new engineering, the teaching construction of "polymer comprehensive experiment" was explored from four aspects: teaching concept, teaching content, teaching practice and evaluation mechanism. This paper put forward the teaching concept of "student-centered, moral education and human cultivation", comprehensive experiment project based on the whole process, new technology and new achievements integrated in teaching in time, and diversified evaluation mechanism implied in urging teaching. In the process of teaching, we should not only strengthen the students' comprehensive use of basic knowledge, but also pay attention to the cultivation of students' innovation ability, engineering practice ability and professional spirit, so as to meet the requirements of new engineering practice.关键词：New engineering;Course teaching construction;Engineering ability training;Polymer comprehensive experiment
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发布时间：2022-08-30 - 摘要：Emerging engineering construction is an important measure of discipline construction, which can support innovative development,adopt to new technology/industry/economy. Meanwhile, it can cultivate and bring up lots of creative talents who are the primary force guiding development of technology and industry. "Principles for Polymer Processing" is a compulsory course of polymer materials discipline,it plays crucial role in the specialty course system. Under the background of Emerging Engineering, in this paper, the current situations and problems were concluded from the aspects of textbook selection, teaching staff construction, classroom teaching and practical teaching,etc. Furthermore, corresponding solutions were given.关键词：Emerging engineering;Polymer materials;Polymer processing;Course construction
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发布时间：2022-08-30 - 摘要：In order to achieve the training goal of innovative applied talents, the applicable teaching system of "Polymer Materials" course was established in view of prerequisites.Teachers concentrate on teaching, use of thematic teaching and scientize teaching design. By these measures, knowledge point processing is strengthened, curriculum structure is optimized, students' interest in learning is improved, and students' professional ability, professional accomplishment and comprehensive quality are cultivated.关键词：Polymer materials;Application ability;Curriculum ideology;Teaching design;Teaching system
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发布时间：2022-08-30 - 摘要：Under the background of the emerging engineering, several colleges and universities have made many effective efforts on engineering education reform. As a new rapidly developing cross-discipline of polymer major, functional polymers also must make some reform to meet the emerging engineering requirement for polymer professionals. In this paper, the problems existing in the cultivation of functional polymer students' innovation ability were studied, and the course objectives, teaching contents, specific implementation methods and teaching experience of functional polymer was summarized. Those suggestions will help to arouse initiativity of students, broaden their scientific vision and enhance their innovation ability under the background of innovation-oriented talents cultivation.关键词：Emerging engineering;Functional polymer;Innovation-oriented talents;Teaching reform
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发布时间：2022-08-30 - 摘要："Plastic Formula Design" is a practical course. How to combine theoretical teaching with practical operation organically plays an important role in cultivating students' ability to solve practical industrial production problems by using theoretical knowledge and in developing innovation and entrepreneurship by using the knowledge they have learned. This paper explores the reform of theoretical teaching and practical teaching in the course of plastic formula design. In the teaching practice, the teaching quality is improved through the reform of learning method guidance, classroom interaction design, comprehensive experiment setting and so on, so that students can master the plastic products and formula design process comprehensively, and cultivate and improve students' synthesis quality, in order to they can better enter the society and develop expertise.关键词：Plastic formula design;Teaching reform;Classroom teaching;Method
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发布时间：2022-08-30 - 摘要：The blending teaching model based on the "Polymer Materials Processing Technology" open online course was developed in Changzhou University, the teaching results in two different semesters were analyzed. The results showed that the teaching effects and learning efficiency were modified by deeper integration between online self-learning and teaching in classroom. The effective process evaluation is the critical path to maintain the interesting of students. The effective instructional design will promote the development of quality abilities of students. At last, it is important to update the online teaching resources in time. The study in this paper will provide some advice for the practice of blending teaching model.关键词：Blending teaching;Open online course;Instructional design;Model
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发布时间：2022-08-30
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