最新刊期
卷 30 ， 期 7 ， 2017
- 摘要：Polyimide is one kind of polymer material with a great potential of development. With high thermal expansion coefficient, the application of polyimide is limited, so reducing the thermal expansion coefficient of polyimide has become one of the research hotspots. The main preparation methods of polyimide films with low thermal expansion coefficient were reviewed. These methods include molecule structure design of monomer, copolymerization, blending method and adding nanoparticles. The effects of process conditions(such as casting methods, drawing conditions and so on) on thermal expansion coefficient were presented. Finally the future development trend of polyimide films with low thermal expansion coefficient was prospected.关键词：Polyimide film;Thermal expansion coefficient;Research status;Prospect
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发布时间：2022-09-06 - 摘要：In this article, the application of light irradiation on living radical polymerization reactions (LRP) has been summarized in terms of the initiation and catalysis of polymerization. The effects of light irradiation on nitroxide-mediated polymerization (NMP), atom transfer radical polymerization (ATRP), reversible addition-fragmentation chain transfer polymerization (RAFT) and cobalt-mediated radical polymerization (CMRP) are analyzed from the aspect of mechanism. In comparision with conventional radical polymerization, light mediated living radical polymerization could generate free radicals under mild conditions, lower the activation energy of catalysis reaction and improve the polymer-end functionality. We hope the review will not only promote the applications of light-mediated radical polymerization but also stimulate a new idea to further advance light-mediated reactions.关键词：Light mediated polymerization;Living radical polymerization;ATRP;RAFT;NMP
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发布时间：2022-09-06 - 摘要：Polypropylene is one of the five general plastics, which has a good comprehensive performance. However, its poor flame retardancy restricts its further applications. As a type of environmentally friendly inorganic flame retardnant, magnesium hydroxide (MH) is extensively applied in flame retardant polypropylene, but the strongly polar MH flame retardant leads to the poor compatibility between MH particles and the polymer matrix, as well as the poor dispersion of MH in polymer matrix, which not only results in the low flame retardant efficiency, but also brings severe negative influences to the mechanical properties of composites. To Improve the interface compatibility between flame retardant particles and polymer matrix, it is essential to change the surface performance of filler. This paper presents a summary of the main advances in different methods of surface modification for MH in flame retardant polypropylene in recent years, including the surface chemical modification, surface grafting modification and microencapsulation. The trends of future developments of the surface modification of MH in flame retardant polypropylene composites have been proposed based on this view.关键词：Magnesium hydroxide;Surface modification;Flame retardant;Polypropylene
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发布时间：2022-09-06 - 摘要：Polyaniline (PANI) has good electrical conductivity and unique doping-dedoping properties, and it has become a high-profile conductive polymer material in recent years. Because of its unique properties of scratch-resistant, anti-pitting and passivation, PANI has owned great application prospects in the field of metal anti-corrosion. The presence of the benzene ring in the polyaniline structure makes its molecular chains more rigid, and intermolecular hydrogen bonds lead to its insoluble, refractory, poor processing performance, which seriously hampered the application of polyaniline. The doping process can effectively improve some properties of polyaniline or give it a new function, which extends the application of polyaniline. This article reviews the doping way and the doping mechanism of polyaniline, preparation methods of polyaniline anti-corrosion material, as well as its application in the field of metal anti-corrosion, and looks forward to the research and application prospects of polyaniline.关键词：Polyaniline;Doping;Anti corrosion performance
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发布时间：2022-09-06 -
The Preparation and Anticorrosive Performance Research of A Novel UV-curable Epoxy Acrylate Emulsion
摘要：The modified epoxy acrylate resin was prepared under a certain temperature with nonionic surfactant, epoxy resin E-20 and acrylic acid. Afterwards, the UV-curable waterborne epoxy emulsion was obtained by phase inversion method. The choices of raw material, reaction condition and emulsifying process were optimized. The comprehensive performance analysis, especially the particle size of emulsions as well as the electrochemical performance and salt-spray corrosion of paint films under different conditions (such as the types of epoxy resin and photoinitiator) were carried out. Results showed that the stability of the emulsion and the film performance (including paint film mechanical properties, electrochemical properties and corrosion resistance) would be the best with the selection of epoxy resin E20, light initiator IRGACURE 651, esterification reaction temperature 105℃, reaction time 3 hours, emulsifying temperature 25~30 ℃ and stirring speed 800 r/min.关键词：Water borne resin;Epoxy acrylate;UV curable;Metal corrosion- 8
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发布时间：2022-09-06 - 摘要：In this article, the interaction between halloysite nanotube and lysozyme used as model protein was studied by spectroscopic method. The fluorescence of lysozyme was quenched upon addition of halloysite nanotubes and the quenching mechanism belonged to static quenching. Intensity increase of resonance light scattering may be caused by the increase of molecular size as a result of halloysite nanotube-lysozyme complex formation, which was consistent with the data of UV-vis absorption spectra and static quenching mechanism. Interaction site between halloysite nanotubes and lysozyme was around the tryptophan in lysozyme based on synchronous fluorescence spectra, where the secondary structure of lysozyme was changed. When the concentrations of halloysite nanotubes were 100 mg/mL and 200 mg/mL, the decreased α-helix structure content were 3.28% and 6.89%, respectively, calculated by the data of circular dichroism spectra.关键词：Halloysite nanotube;Lysozyme;Fluorescence quenching;Resonance light scattering;Circular dichroism spectraspectroscopic
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发布时间：2022-09-06 - 摘要：Porous poly(vinyl alcohol) (PVA) films (PPF) were prepared that PVA was used as matrix, glutaraldehyde was used as cross-linking agent, acetic acid was used as catalyst and polyethylene glycol 6000 (PEG-6000) was used as porogen, followed by loading titanium dioxide (TiO2) on it to obtain PPF loaded with TiO2 (PPF-TiO2). Infrared spectrometry, scanning electron microscope and spectrophotometer were used to investigate the cross-linking conditions, microstructure shapes before and after loading TiO2, and the degradability of PPF-TiO2 to methyl orange. The results showed that PPF with appropriate cross-linked degree and pore sizes could be fabricated with 5% glutaraldehyde and PEG-6000 (0.6 times of the weight of PVA). The loading weight of PPF to TiO2 reached 43% of the total weight when the loading temperature was 40℃ and loading time was controlled at 2h. Furthermore, the degradability of PPF-TiO2 to methyl orange was faster than that of TiO2 purchased.关键词：Porous film;Poly(vinyl alcohol);Titanium dioxide;Loading
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发布时间：2022-09-06 - 摘要：Star-shaped Hydrophobically Associating Water-soluble Polymer(P(AM/NtBA/NaAMPS))was prepared by single electron transfer living radical polymerization(SET-LRP)with acrylamide(AM), sodium 2-acrylamido-2-methylpropane sulfonate(NaAMPS)and N-tert-butylacrylamide(NtBA)as comonomer, Cu0 powder and Me6-TREN as catalytic system and CCl4 as multifunctional initiator. Effects of the initiation temperature, hydrophobic monomer dosage, AMPS dosage, initiator dosage, catalyst dosage and monomer concentration on molecule weight were investigated by Control variable method. The optimum synthesis conditions were determined and the solution properties were investigated.The results show that as the acrylamide(AM) content is 93.6%(mol)in total monomer, 2-Acrylamide-2-methylpro panesulfonic acid(AMPS)content is 5%, N-tert-butylacrylamide(NtBA)content is 1.4%. And as the monomer concentration is 35%, the reaction temperature is 25.0℃, the mass fraction of initiator is 0.4942%, the amount of catalyst is 0.0848%, the deactivation agent is 0.1192%, the maximum molecular weight of the star-shaped hydrophobically associating water-soluble polymer can reach up to 2.67×106.The polymer have temperature resistance and salt tolerance,and the solution property of star-shaped hydrophobically associating water-soluble polymers was similar to the line-shaped polymer. In addition, the effect of CaCl2 on the apparent viscosity of the hydrophobically associating polyacrylamide was more significant than NaCl.关键词：Single electron transfer living radical polymerization;Star shaped hydrophobically associating water soluble polymer;N-tert-butylacrylamide;Temperature resistance and salt tolerance
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发布时间：2022-09-06 - 摘要：Alginate has good biocompatibility, biodegradability, hemostatic, antimicrobial properties and promoting healing of wounds. As a kind of polysaccharides in Bletilla striata, a traditional Chinese medicine, Bletilla striata polysaccharide has the function of hemostasis, detumescence and can promote the granulation. In this study, alginate and Bletilla striata polysaccharide were used as raw material, and the composite hemostatic powder was prepared by using lyophilization method. The water absorption rate was measured, and the hemostatic performance was evaluated by using in vitro blood coagulation test and the bleeding animal model. The results indicated that when the amount of porogen in calcium alginate porous microspheres was 0.5%, and the mass ratio of calcium alginate porous microspheres with Bletilla striata polysaccharide was 1∶1, the composite powder showed the best hemostatic effect.关键词：Alginate;Microspheres;Bletilla striata polysaccharide;Hemostasis
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发布时间：2022-09-06 - 摘要：Based on the characteristics of polymerization technology and personal teaching practices,the suggested measures for teaching reform have been given in the following three aspects: the establishment of knowledge system, the training program of students’ exertion ability and the implementation of teaching process. Besides, considering the characteristics of our college and the objectives in talent cultivation, the teaching contents have been optimized according to the logical relationship of "Principle-Technology-Application-Equipment". The course contents have been updated to effectively stimulate students’ interests, cultivate their curiosity and creativity and improve teaching quality. Furthermore, the author also put forward some teaching opinions for the combination of Flipped Class Model with Project Teaching Means and the comprehensive arrangement of the practice teaching, which have been practiced and improved in real classroom teaching as well.关键词：Polymerization technology;Teaching method;Reform practice
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发布时间：2022-09-06 - 摘要：Based on the requirements of specialized accreditation of engineering, problems of the course reform of modern material testing technique were analyzed. Taking the product-oriented approach as a guide, the case teaching method based on engineering project and scientific research project was used. The flexible engineering problem was designed and conducted in the classroom for improving the students’ ability to analyze and solve engineering problems. Kinds of teaching methods were used in and out of the classroom such as project, discussion and heuristic. And also, we emphasized the multi-media teaching with PowerPoint, and strengthened a small-class experimental teaching, and established a diversified student evaluation system. The capacity of innovation and teach work and interpersonal commutation was also development.关键词：Specialized accreditation of engineering;Modern material testing technique;Case study;Small class teaching
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发布时间：2022-09-06 - 摘要：In order to cultivate and stimulate students’ interest in polymer science and technology, Zhejiang University from 2004 began to hold "Modern history of polymer" elective courses to undergraduate students of polymer materials. By allowing students to understand the process of the establishment of polymer science, understanding of the establishment and development of polymer industry, a comprehensive understanding of polymer science and discipline knowledge, structural understanding was expected to be established in students. Along two important indexes including the development of polymer science and technology in China and in the world, the emergence of the famous polymer scientists, the production of a variety of historical significance of polymer materials and experimental technology were introduced for the students to show the development of polymer science and technology surge high and sweep forward in history. After more than and 10 years of trial and effort, the course has formed its own teaching features in the teaching content, teaching methods and assessment methods, and played a positive role in stimulating and cultivating undergraduate students’ interest and enthusiasm for polymers.关键词：Modern history of polymer;Polymer science;Undergraduate teaching
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发布时间：2022-09-06
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