最新刊期
卷 34 ， 期 1 ， 2021
- 摘要：Poly (decamethylene terephthalamide) (PA10T) is a new type of bio-based heat-resistant nylon developed independently in China. It has excellent mechanical properties, heat resistance, wear resistance, dimensional stability, chemical corrosion resistance, hydrolysis resistance and good processability. Moreover, it has low water absorption rate and broad application prospects. It is a special engineering plastic with rapid development in recent years. The research on the modification of PA10T has always been the focus of academic and industrial circles. This article reviews the latest research progress of PA10T modification from 2015 to 2020. The preparation methods (in-situ copolymerization, melt blending, synergistic modification) and properties (crystallization, mechanics, thermal oxidative aging, flame retardancy, rheology, light transmission and comprehensive properties) of PA10T were mainly described. The research and industrial development status of PA10T were analyzed in detail, and the future development direction and potential application fields of PA10T were prospected.关键词：PA10T;Modification study;In situ copolymerization;Melt blending
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发布时间：2022-08-30 - 摘要：PMMA bone cement is an implant material used for the treatment of spinal fractures and the fixation of joint prostheses. Three main defects exposed in clinical application can be concluded as: the exothermic polymerization of MMA leads to the thermal necrosis of bone tissues, the micro-crack growth from internal defects brings about the poor mechanical performance, the physical bonding to bone in terms of the mechanical interlocking lowered the long-term stability of implants. According to these mentioned performance defects, this paper proposes targeted scientific research thoughts, sums up the typical examples of current research, discusses detailed research findings and concluded current research directions. Besides that, based on the nature of performance defects, this paper also proposes the significance of ideal modification and its purpose, lays the theoretical and experimental foundation for future clinical application of new type PMMA bone cement.关键词：PMMA bone cement;Performance defects;Curing exotherm;Mechanical properties;Bioactivity
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发布时间：2022-08-30 - 摘要：Poly (3-hydroxybutyrate-3-hydroxyvalerate) (PHBV) nanofibers have been attractively used as biomedical materials due to its high specific surface area, high porosity, biocompatibility, and biodegradability. This review summarizes the methods to control the morphology and structure of PHBV electrospun nanofibers nanofiber by adjusting the solvent, concentration, additional salts and polymers of PHBV electrospinning solution. Based on the recently research of PHBV nanofibers in tissue engineering and drug delivery carriers, the improvement of hydrophilicity and mechanical properties PHBV nanofibers are emphatically introduced. In addition, some problems existing in preparations and applications of electrospun PHBV nanofibers in biomedical field are further proposed. Finally, the development trends and prospects for PHBV nanofibers are forecasted.关键词：Poly(3-hydroxybutyrate-co-3-hydroxyvalerate);Electrospinning;Nanofiber;Tissue engineering;Drug carrie
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发布时间：2022-08-30 - 摘要：As a polar synthetic rubber, CR with excellent flame retardant, good resistance to heat, weather and chemicals, suffers problems like poor processability and unsatisfied fatigue properties. Trans-1,4-butadiene-isoprene copolymer (TBIR) can significantly improve the comprehensive properties of neoprene (CR), especially the fatigue resistance. Considering that the curing systems and curing mechanisms of CR and TBIR are different, and their polarity are quite different. CR and TBIR parent compounds are prepared with different curing agents and then CR/TBIR blends with different blending ratios were prepared, and the phase structure, crosslinking structure and mechanical properties of CR/ TBIR blends were systematically studied. It was found that TBIR island-phases with dimension of less than 300 nm were uniformly distributed in CR matrix. With the increasing of TBIR dosage, the crosslinking densities of CR/TBIR vulcanizates increased gradually: the crosslinking densities of CR/TBIR vulcanizates containing 10~20 TBIR increased by about 20~30%. Due to the changes in the crosslinked structure and phase structure, the tensile strength, elongation at break and compression permanent deformation of CR/TBIR vulcanizates were improved compared with CR vulcanizate. Particularly, the fatigue resistance of CR/TBIR vulcanizates improved. The 1st flexural fatigue lifetime of the CR/TBIR vulcanizates was 1.5~2.2 times of that of the CR vulcanizate, and 6th flexural fatigue lifetime of the CR/TBIR vulcanizates was 2~4.6 times of that of the CR vulcanizate.关键词：Trans-1, 4-(butadiene-co-isoprene) copolymer rubber;Chloroprene rubber;Phase structure;Crosslink density;Fatigue resistance
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发布时间：2022-08-30 - 摘要：This paper studied the influence of different modification methods of hemp fiber on the strengthening effect of natural rubber. By using hemp fiber to reduce the carbon black content in the system, the heat generation of hemp fiber reinforced natural rubber composite (HF/CB/NR) was reduced while the mechanical properties of rubber material were guaranteed. The results showed that the three parts of carbon black could be reduced by adding one part of alkali treatment to hemp fiber, and the mechanical properties of the two materials are equivalent. Through the compression heat generation test, it was found that HF/CB/NR heat generation was significantly reduced by 5.6% after adding hemp fiber treated with alkali treatment and coating with natural rubber latex. The addition of hemp fiber can significantly reduce Payne effect, so that the material can maintain a higher stiffness under higher strain关键词：Hemp fiber;Natural rubber;Mechanical properties;Low heat generation
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发布时间：2022-08-30 - 摘要：Two new fluorene-based benzoxazine monomers(3-fluorenyl-3,4-dihydro-1,3-benzoxazine(FBZ-1) and 3- fluorenyl-6-methoxyl-3,4-dihydro-1,3-benzoxazine(FBZ-2))were synthesized through the reaction of phenol/para methyl phenol with formaldehyde and 2-anlinofluorene. 2-anlinofluorene was from the nitrification and reduction of fluorene. The chemical structures were confirmed through FTIR, 1H NMR and 13C NMR analyses. The polymerization reactions of the precursors were monitored with Differential Scanning Calorimetry (DSC) and FT-IR. The curing kinetics were investigated, activation energy and optimum curing temperature were obtained. The thermal properties of cured polymers were evaluated through DSC and Thermo Gravimetric Analysis (TGA). The two fluorene-based benzoxazines show that the typical curing characteristic of the oxazine ring-opening centred at 231.2℃ for FBZ-1 and 228.7℃ for FBZ-2. The thermal decomposition temperature (5% weight loss) and the char yield (Yc) of fluorene-based polybenzoxazine at 850℃ is 290℃ and 40.9% for FBZ-1, 299℃ and 36.9% for FBZ-2. Limit oxygen index(LOI) is 33.86, 32.26, respectively.关键词：Benzoxazine;Fluorene;Curing kinetics;Thermal properties
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发布时间：2022-08-30 - 摘要：The structures and properties of natural rubber/Nd-based butadiene rubber (NR/Nd-BR) self-supporting rubber of run-flat tire modified with three kinds of trans-1, 4-poly (butadiene-co-isoprene) copolymer rubber (TBIR) with different mooney viscosity and butadiene repeating units were invested. The results showed that, compared with NR/Nd- BR (50/50) compounds, NR/Nd-BR/TBIR (45/45/10) compounds showed lower Payne effect, the filler network structures weakened obviously. Carbon black dispersity test showed that NR/Nd-BR/TBIR vulcanizates presented excellent filler dispersion. Dynamic thermo-mechanical performance analyzer (DMA) showed that the compatibility between NR and Nd-BR was improved significantly after modified with TBIR. The obviously improved compatibility between NR and Nd- BR and better filler dispersion made NR/Nd-BR/TBIR self-supporting rubber of run-flat tire showed excellent fatigue resistance, lower rolling resistance and heat build-up.关键词：Trans-1, 4-poly(butadiene-co-isoprene) copolymer rubber;Compatibility;Run-flat tire;Self-supporting rubber;Fatigue resistance
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发布时间：2022-08-30 - 摘要：The radical chain copolymerization (RCCP) that two or more monomers are simultaneously polymerized in chain polymerization process is a very important content in Polymer Chemistry course. RCCP is significant for several considerations such as changing chemical and physical property of polymers, extending variety of polymers, and improving usability of polymers. In addition, RCCP provides a method for the reactivity of monomers and radicals, the principle of polymerization, and the possibility of a new polymer synthesis. The binary RCCP is the simplest combination, which is an ideal model for various copolymerization behaviors. In this paper, the behavior curves of binary RCCP were colorized for clarifying the relationship between two different monomers and different symbols were added into them. The curves were drawn by double coordinate system and different types of copolymerization behavior were discussed, which is very useful for the undergraduates to understand the mechanism of radical copolymerization and to control the copolymer composition.关键词：Radical polymerization;Binary copolymerization;Colorized curves;Double coordinate system
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发布时间：2022-08-30 - 摘要：English of polymer sciences is of great significance to the cultivation of modern materials science talents. Aiming at the current situation that students in most colleges and universities do not pay much attention and are not willing to learn to the special English, based on the characteristics of polymer materials courses, and in order to make students better master the important content of the course and stimulate students' enthusiasm for learning, we have tried to change the teaching contents that can cover basic organic, inorganic, polymer and advanced knowledge of polymer materials, and through adjusting the evaluation system and using Rain Classroom as teaching technique etc., thus improve students' ability in English writing and literature reading.关键词：Chemistry English;Course content;Teaching technique;Teaching reform
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发布时间：2022-08-30 - 摘要："Polymer Chemistry" is one of the four core professional courses and the first professional course for undergraduates of polymer material and engineering specialty. The content of polymer chemistry course includes the basic concepts, the methods, and the mechanisms of polymerizations. In this paper, on the basis of the status analysis for polymer chemistry course in civil engineering university, several suggestions were put forward to strengthen the specialized discipline characteristics, including adding entry points of building materials, interactive teaching adapted for engineering students, complementary with polymer chemistry experiments, and combining with scientific research and industrial practice.关键词：Polymer chemistry;Civil engineering;Teaching reform;Discussion and practicing
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发布时间：2022-08-30 - 摘要：According to the guidance of accreditation standard, the present situation and existing problems of comprehensive experiments on sizing and weaving technology were analyzed. Based on the perspective of accreditation, the reform ideas and methods for the experiment curriculum were pointed out. To fulfill the accreditation requirements and improve students’ ability of solving the complex engineering problems, the supported graduation requirements of the course were specified. In addition, the teaching program and experimental equipment were updated, the experimental teaching programs such as preparation of sizes, performance measurement of the size paste and film were added. The proportion of designing and innovative experimental projects was increased, and the assessment method of the course was updated, so as to improve the students' ability to solve complex engineering problems and the sustainable improvement of the course content was realized.关键词：Accreditation;Polymer sizes;Sizing technology;Comprehensive experiments;Reform
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发布时间：2022-08-30 - 摘要：《Polymer Chemistry》 is an important basic course of polymer materials and engineering. A lot of basic chemical theoretical knowledge is integrated into polymer chemistry, so the introduction of relevant basic chemical theoretical knowledge in polymer chemistry teaching will help students overcome the fear of difficulty, improve their interest in learning, help students understand the key and difficult points, and effectively improve the teaching effect. According to the teaching practice, this paper introduces some examples and experience of the effective integration of basic chemical theory knowledge such as free radical, activation energy and transition state into polymer chemistry teaching. Practice shows that the effect of "teaching " and "learning " can be obviously improved by "seeking new knowledge from old knowledge" .关键词：Polymer chemistry;Chemical theoretical knowledge;Teaching
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发布时间：2022-08-30 - 摘要：Based on computational thinking and tooling and programmatic problem-solving method, a problem-solving software for polymer chemistry was designed and developed for the purpose of teaching, and has been used in the teaching of polymer chemistry with a remarkable effect being achieved. It abstracts the common calculation problems on step polymerization, radical polymerization, copolymerization, etc. into 63 typical types of questions, and have the important calculation problems frequently encountered in teaching of polymer chemistry being solved and their result also being graphical displayed when needed, with the teaching difficulties being melted, and the tooling and programmatic problemsolving method being demonstrated to the students, which will have their related awareness being cultivated. It significantly improve the teacher’s efficiency and can support the teacher to carry out innovative "earning centered" teaching. An online version of it is also design and developed. And this enables the students to use it conveniently anytime and anywhere through the mobile internet to do cloud computing, to conduct question inquiring and knowledge construction actively, and to learn deeply, easily and efficiently.关键词：Polymer chemistry;Problem-solving software;Design;Development;Calculation;Visualization;Cloud computing
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发布时间：2022-08-30
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