最新刊期
卷 32 ， 期 3 ， 2019
- 摘要：Polyampholyte hydrogels have attracted great attention due to their excellent performance. This new type of hydrogels not only show high strength and toughness, but also show fatigue resistance and self-healing, along with biocompatibility. Thus, those hydrogels have great potential as structural biomaterials,such as cartilage and tendon. In this review paper, we firstly describe the factors that influence the performance of PA hydrogels, including the charge ratio of cationic monomer and anionic monomer, the monomer concentration and the crosslinker concentration. Then we discuss the chain structure, toughening mechanism, self-healing mechanism, fracture behavior, and some applications of PA hydrogels. Finally, we summarize some open questions on PA hydrogels that may provide opportunities.关键词：Polyampholyte hydrogels;Tough;Self-healing;Structural biomaterials;Fracture mechanism
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发布时间：2022-09-02 - 摘要：Due to the limitation of size and specific surface area of traditional adsorbent materials, itisurgentto seek new types of adsorbent materials. Through the study of the structure and properties of chitosan and nanomaterials, a variety of chitosan nano-substrate has been widely used. In this paper, the application of chitosan nanomaterials in purifying drinking water was described briefly, and the progress of chitosan nano-materials for removal of dyes and heavy metal ions from wastewater in recent years was reviewed. The current problems and future development of chitosan-nanomaterialswere summarized, which lays a theoretical foundation for the further development of excellent adsorption materials.关键词：Chitosan nano-substrate;Printing and dyeing wastewater;Heavy metal ion;Water treatment
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发布时间：2022-09-02 - 摘要：Poly(L-lactic acid) (PLLA) is regarded as one of the most promising green bio-based polymer materials in industrial application, because of its excellent biodegradability, biocompatibility, high mechanical strength and easy processing performance. However Poly(L-lactic acid) (PLLA) exhibits poor toughness, low crystallization rate and poor heat resistance,these inherent drawbacks limit its development and application in engineering,electronics, electrical and automotive engineering, and 3D printing. Progress in improving the heat resistance of poly(L-lactic acid) are reviewed in this article. The heat resistance of PLLA were enhanced through several methods, such as adding nucleating agents, preparing stereo-complex microcrystal complexes, and blending with nano-particles and high heat resistance polymer materials, which enlarged its application in engineering fields.关键词：Poly(L-1actic acid);Heat resistance;Nucleating agents;Stereo-complex composite
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发布时间：2022-09-02 - 摘要：A polymer mainly prepared with 6-aminohexanoic acid and another assistant five kinds of amino acids were synthesized in this study for evaluating the physicochemical characteristic, in vitro and in vivo bioactivity as bone repair materials. The transforms infrared (FT-IR)、X-ray diffraction analysis (XRD)、differential scanning calorimetry(DSC) and thermal gravity analysis(TG) were investigated and characterized; The scanning electron microscopy (SEM) was tested for evaluating the in vitro bioactivity after soaking the polymer into simulated body fluid (SBF) with five days; The implantation of polymer into muscles and femur condyle of rabbits was assessed for evaluating the in vivo bioactivity of the polymer. The results showed that the polymer possessed amide band and was semi-crystallization structure, further the melting temperature and crystallization temperature was 205.9℃ and 159.5℃,respectively; The polymer could induce the form of apatite in the surface of polymer, showing good bioactivity; The implantation of polymer into muscles and femur condyle of rabbits results stated that the polymer had no visible inflammation and had contacted directly between implants and tissue without newly formed fibrous connective tissue. The fluorescence results showed that the polymer may possessed ectopic osteogenesis and have exactly great osteoconductivity in vivo.关键词：Hexa-amino acids;Polymer;In vitro bioactivity;In vivo bioactivity
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发布时间：2022-09-02 - 摘要：In this contribution, we reported the investigation of SBS reinforcd by silicon dioxide-graft-polyisoprene core-shell nanoparticle (SiO2-g-PIP). First,the hydroxyl on the surface of SiO2 nanoparticles was reacted with 2-methyl-2-[(dodecylsulfanylthiocarbonyl) sulfanyl] propanoic acid to afford a trithioester-capped SiO2 (denoted). SiO2-CTA used as the nanoparticles chain transfer agent, SiO2-g-PIP core-shell nanoparticle was synthesized via reversible addition-fragmentation chain transfer polymerizations (RAFT). The results of FTIR spectroscopy and TGA showed that the grafting weight of PIP block in SiO2-g-PIP is 2.1wt%. Then,SiO2-g-PIP and SiO2 were simultaneously incorporated into SBS. The results of scanning electron microscope (SEM) showed that SiO2 microdomains in SBS/SiO2-g-PIP composite had much better dispersion and distribution than SiO2 in SBS/SiO2 composite. It is the filler-rubber interaction of SBS/SiO2-g-PIP composite that endowed the composite with improved mechanical properties.关键词：SiO2-g-PIP;RAFT polymerization;Nanostructured composite;Mechanical properties
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发布时间：2022-09-02 - 摘要：Compared with the polymer solution, the polymer microsphere solution is a discontinuous phase, and the particle size distribution of the microspheres is more concentrated. It can "plug large pores and not plug small pores", to a certain extent, the swept volume of water phase were increased, and the phenomenon of "profile inversion" was slowed down. In recent years, polymer microsphere flooding technology research and field test have received extensive attention. In order to meet the needs of profile control technology in offshore oilfield,a hydrophobically associating polymer microsphere was synthesized by inverse emulsion polymerization. Chemical characterization and core seepage experiments were used to study the particle size distribution, slow swelling, plugging,reservoir adaptabilityand transmission and migration capacity of polymer microspheres. The results show that the water-soluble monomer AMPS and the hydrophobic monomer alpha methylstyrene can be copolymerized with acrylamide and sodium acrylate to form a random distributed hydrophobically associating copolymer, that is microsphere material. On this basis, nine microsphere samples (AMPS) were synthesized by four-factor three-level orthogonal test to study the effects of AMPS content, emulsifier content, initiator content and temperature on microsphere particle size. The initial particle size of AMPS-8 microsphere is about 2µm,and the particle size is stable at about 18µm after the hydration of 240h. The expansion ratio reached 8 to 9 times, and the residual resistance coefficient is the largest when the core permeability is 1600 × 10-3 µm2,reaching 9. 53,indicating that the permeability limit is 1600 × 10-3 μm2 and the microsphere has a strong retention and plugging effect in the core.Under the condition of injected water in Bohai oilfield, there is little difference in the median size of AMPS hydrophobic polymer microspheres, indicating that it has good salt resistance. The transport and migration experiments of 60cm long core were carried out by using AMPS-8 microspheres with better expansion effect. The results show that the residual resistance coefficient near the entrance is as high as 19. 417,the residual resistance coefficient of the middle is 6.6,and the residual resistance coefficient near outlet is 2.8,indicating that AMPS-8 microspheres have good deep transport and migration ability.关键词：Reverse phase emulsion polymerization;Hydrophobic microspheres;Particle size distribution;Slow expansion performance;Plugging effect;Physical simulation
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发布时间：2022-09-02 - 摘要：Polycondensation is one of the fundamental components of "Polymer Chemistry",and its basic rules and characteristics are introduced mainly by linear polycondensation in domestic textbooks. Therefore, the synthesis kinetics of a typical linear polycondensation product, Polyethylene glycol adipate (PEA),becomes a main content of "Polymer Chemistry Experiment". Melt polycondensation kinetics experiment is included in the course of "Polymer Chemistry Experiment" of Sichuan University, which studies on the kinetics of melt polycondensation in the synthesis of linear polyester PEA under the condition of acid catalysis. In this paper,some problems in data processing havebeenanalyzed, a measure of improvement is put forward to solve the problems. Two different methods are used to calculate the reaction rate constant k and the activation energy E, under the condition of changing temperature. Finally, the differences between the experiment results are compared before and after the improvement.关键词：Linear melt polycondensation;Kinetics;Data processing;Adipic acid
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发布时间：2022-09-02 - 摘要：Rubber technology is the characteristic optional course of polymer material and engineering. In view of the problems existing in the current teaching of this course,such as many knowledge points,monotony of teaching content and the absent interest of students,some proposals for the reformation of teaching are proposed in this paper involving the renewal and reorganization of teaching content, reform and innovation of teaching methods,flexible and diverse evaluation methods, the combination of experiments and practice with industrial production in internship training, and cooperative teaching team construction mechanism. And then, the proposals are applied to the teaching activities of this course. The practice shows that the teaching reformation of rubber technology course has obtained remarkable achievements in terms of teaching quality,teaching efficiency and talent cultivation.关键词：Rubber technology;Teaching reformation;Discuss
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发布时间：2022-09-02 - 摘要：The importance of experimental course in the major of polymer materials was discussed first,and then an innovation experiment was planned, which was named fabrication, structure and property of poly (lactic acid)/calcium sulfate whisker (PLA/CSW) composites via in-situ melt polycondensation. On the basis of students' consulting literatures, understanding the basic theories and designing the proper experimental routes, PLA/CSW composites characterized by uniform dispersed whisker and well-bonded interfaces were prepared successfully. The molecular weight, interfacial morphology and crystallization behavior of the composites were measured, and finally a copy of well-organized experimental report for every student was required. This innovation experiment was related to various knowledge points derived from organic chemistry, polymer chemistry, polymer physics, composite materials, surface and interface of materials and modern materials analysis and testing technology, etc. The whole process was consisted of literature consultation, data analysis, collaboration, group discussion and writing the experimental reports. It gave the positive contributions to the improved all-round abilities of students, as will lay the solid foundation for their developments in future.关键词：Innovation experiment;Reform of experimental teaching;Poly(lactic acid);Calcium sulfate whisker;In-situ polymerization
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发布时间：2022-09-02 - 摘要：As one of the three concepts of the engineering education professional certification, Outcome-based Education(OBE) represents the direction of the Chinese engineering education reform, and the implementation of OBE in curriculum teaching design is the key to improve the teaching quality. In this paper, taking the teaching of "Polymer Synthesis Technology" as an example,the design of curriculum objectives,teaching contents,teaching methods and evaluation methods based on OBE are discussed. Through the teaching reform and practice, the teaching effect has improved and the expected teaching goal has achieved.关键词：Polymer synthesis technology;Outcome-based Education;Teaching design;Professional certification
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发布时间：2022-09-02
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