最新刊期
卷 33 ， 期 7 ， 2020
- 摘要：Chitin is the most abundant amino polysaccharide in nature and its most important derivative chitosan has been widely studied in the academic and industrial circles worldwide in recent years. Appropriate and efficient structural modifications enable chitin and chitosan to gain full development with potential application prospects. This paper focuses on the chemical modification of chitin and chitosan and its application in the related fields of medicine and pharmacy.关键词：Chitin;Chitosan;Chemical modification;Medical application;Wound healing
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发布时间：2022-08-31 - 摘要：Activators regenerated by electron transfer for atom transfer radical polymerization (ARGET-ATRP) as a kind of active/controllable radical polymerization technology, can overcome the shortcomings of conventional ATRP reaction such as high toxicity of initiator, high usage of catalyst and demand of anaerobic conditions. The ARGET-ATRP technology can be applied for synthesizing the polymers with special structures and properties, and has become a research hot topic in the polymer field with a wide application prospect. In this paper, the reaction mechanism of ARGET-ATRP technology was described. The research progress on the application of ARGET-ATRP technology in preparation of polymer (such as star polymer, block polymer, hyperbranched polymer, etc.) and material modification (such as inorganic material modification and surface modification of organic material) was reviewed, and the potential application prospected of ARGET-ATRP in the field of textile sizing was prospected.关键词：ARGET-ATRP technology;Reaction mechanism;Polymer;Inorganic material modification;Surface modification of organic material
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发布时间：2022-08-31 - 摘要：The used rubber powder made from the waste tire rubber by crushing and mechanical shearing is a kind of thermosetting polymer, which is difficult to degrade and has high recycling cost. And the mechanical properties are poor due to structure damage in the process of processing rubber powder, limiting its application. However, it still has a certain degree of elasticity, wear resistance and skid resistance, and some excellent properties of rubber. It can also be used after proper modification, and it is expected to replace the rubber in short supply, as well as the prepared sheet and pavement materials. In this paper, the application fields and research status of used rubber powder at home and abroad were reviewed, especially the application and research status of corn straw modified used rubber powder composites were reviewed and analyzed, and on this basis, the application prospect of corn straw modified used rubber powder composites was prospected.关键词：Used rubber powder;Corn straw;Modification;Research status
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发布时间：2022-08-31 - 摘要：Radical homopolymerization of DG in toluene solution was studied by using ester (DG) as raw material and azodiisobutyronitrile (AIBN) as initiator. Single factor experiment and orthogonal test were conducted to study the impacts of reaction temperature, reaction time, initiator type, and initiator dosage on the homopolymerization of DG. The structure of homopolymer (PDG) was characterized by Fourier transfer infrared spectroscopy (FT-IR), gel permeation chromatography (GPC), and thermal gravimetric analysis (TG) technologies. The results showed that the optimum conditions for the reaction were as following: reaction temperature of 110℃, stirring speed of 500r/min, AIBN of 2% (based on monomer weight), and reaction time of 4h. Under these conditions, PDG with good thermal stability was successfully prepared.关键词：DG;Homopolymerization;Optimization
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发布时间：2022-08-31 - 摘要：in order to solve the low viscosity of direct polymerization polyoxalate glycol ester, polyester with high viscosity was synthesized by means of melt condensation polymerization and solid-phase condensation polymerization. Polyoxalate glycol ester was directly fused and condensed at 170℃ with stannum chloride catalyst. Solid phase polycondensation was performed at 125±2℃ for 40h. The characteristic viscosity increased to 0.236dl·g-1.The molecular structure was characterized by ir and NMR.DSC was used to characterize the crystallization temperature of solid phase polycondensation 10℃ higher than that of direct polymerization, reaching 137℃.After solid phase polycondensation, the viscosity increases, the crystallization property changes, and the crystallization temperature increases.关键词：Polyethylene oxalate;Oxalic acid;Melt polycondensation;Degradation
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发布时间：2022-08-31 - 摘要：Microfibrinized cellulose and its dispersions have attracted extensive attention because of their unique properties. The preparation of microfibronized cellulose was studied by means of constant temperature heat treatment with different concentration NaOH solution and high pressure jet. The results showed that the treatment with NaOH solution above 10% had a better effect on the stripping of cellulose, and 12% and 14% NaOH solution promoted the crimp of cellulose rod structure. Micro fiber is changed, the crystallinity of cellulose samples decreased with increasing concentration of NaOH, when NaOH concentration was 14%, micro fibrillating fiber structure by cellulose Ⅰ into cellulose Ⅱ. With the increase of NaOH concentration, the thermal stability of microfibrized cellulose samples becomes worse, the tensile strength and elastic modulus of samples become lower, and the elongation at break hardly changes.关键词：Nanocellulose;NaOH treatment;High pressure jet;Micronization
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发布时间：2022-08-31 - 摘要：Based on the KH570 chemical grafting and SA physical coating method of combining the modified nano silica (SiO2) effectively, get a hydrophobic effect and can effectively dispersed nano filler in the polymer matrix, polylactic acid (PLLA) as polymer matrix, passed the non-solvent induced phase separation method preparation of super-hydrophobic PLLA/SiO2 composite films, the apparent contact Angle from pure PLLA 120° to 153°. The study also found that the crystallization properties of the matrix were different with the different filler contents. With the increase of the modified nano-SiO2 filler contents, the crystallinity of the film increased from 9.8% to 17.19%. The crystallinity plays an important role in the construction of rough structure on the surface of materials.关键词：Nonsolvent induced phase separation;Poly(L-lactic) acid (PLLA);Stearic acid;Silane coupling agent;Super-hydrophobic
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发布时间：2022-08-31 - 摘要：Along with the popularization and extension of emerging engineering education, it become much urgent to cultivate the students’ abilities of self-directed learning, professional practice and creativity. Regarding the existing disadvantages of experimental teaching of polymer materials and engineering specialty in our school, it proposes constructing multi-level and open professional comprehensive experimental teaching system. Through professional basic experiment, professional comprehensive experiment and open experiment, it sets up entire curricula system. Through adopting the teaching form of "flipped classroom" , it establishes the teaching mode with the combination of virtuality and reality, and online and offline organic integration. Using multilevel and selective teaching content meets student’s knowledge demand.By using Capstone teaching mode, it cultivates student’s team cooperation ability and innovative ability. When developing this teaching process, it fits for research and development process of enterprise R&D project. In the form of team cooperation, it can better arouse student’s interest and innovative ability in this specialty, bring the students initiative into play, and enhance student’s holistic cognition to the study of polymer materials.关键词：Polymer materials;Multi-level teaching system;Comprehensive experiment;Three-dimensional teaching;Capstone;Practice model
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发布时间：2022-08-31 - 摘要：The polymerization technology of ethylene and propylene is highly correlated in the course of "Polymer Synthesis Technology" . In this paper, the synthesis technology of high density polyethylene and polypropylene is summarized according to the different polymerization technology, such as bulk, solution, slurry and gas phase. Through the systematization and routinization of complex and diverse polymerization technology, the mastery level of the students will be improved.关键词：Polymerization technology;Propylene;Ethylene;Explanation
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发布时间：2022-08-31 - 摘要：To take advantages of local universities, strengthening distinctive construction of discipline and specialty is a very important way. However, in the process of constructing discipline and specialty, there are many problems such as unremarkable construction of discipline, unconspicuous construction of specialty, separation of characteristic discipline and specialty, be short of high-level personnel and teaching resources, etc. In order to solve these problems, it is very necessary to explore effective path to construct disciplines and specialties. In this paper, College of Materials Science and Engineering, Jilin Institute of Chemical Technology was taken as an example to put forward the characteristic discipline and specialty construction plan and carry on the practice research from the five aspects which contained development orientation, specialty construction, discipline-specialty coordinated development, faculty and educational resources.关键词：Distinctive construction;Discipline;Specialty;Local universities
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发布时间：2022-08-31 - 摘要：Polymer chemistry is a science that studies the synthesis process, reaction mechanism and application of polymer compounds. More and more attention has been paid to the teaching and research of polymer chemistry. And researchers in polymer face even greater challenges. Hence, based on the teaching experience in our school for many years, the problems are described briefly in this article, which is encountered in the teaching process of polymer chemistry. In order to overcome these problems, a series of teaching reforms have been carried out under the promotion of the construction of the double first-class universities of province. The reforms in teacher resources, teaching methods, learning platforms and educational models have been summarized and applied to the teaching of polymer chemistry in our university. Good feedback has been obtained from the students, and the comprehensive qualities of the students have been improved in practice. More importantly, the course construction of polymer chemistry has been put forward greatly.关键词：Polymer chemistry;Teaching reform;Double first-class
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发布时间：2022-08-31
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