最新刊期
卷 33 ， 期 4 ， 2020
- 摘要：The flame retardant mechanism and ceramifiable mechanism of silicone rubber were briefly introduced. According to the difference in flame retardant, fillers and char layer structure, silicone rubber was divided into two categories, flame retardant and porcelain. The research progress of flame retardant properties and char formation structure of flame retardant silicone rubber and ceramicizable silicone rubber were reviewed. The analysis shows that the char layer formed during combustion was loose and porous if the silicone rubber was filled with physical or chemical intumescent flame retardant. The char had excellent flame retardant and heat insulation performance, but poor strength. Silicon rubber with non-intumescent flame retardants had relatively dense carbon layer structure, but its surface was not uniform with holes and cracks on it. The flame retardant effect was not good. The ceramic char layer formed by the combustion of the ceramic rubber filled with the porcelain filler was hard and compact. The char layer has excellent refractory durability, but was inferior to the expanded char layer in terms of heat insulation. The char layer has both loose insulation and solid durability, which may be the possible development direction of flame retardant silicone rubber in the future.关键词：Silicone Rubber;Char structure;Flame retardant;Ceramifiable
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发布时间：2022-08-31 - 摘要：Hydrogels, a kind of smart soft material that consists of water and distinctive 3D cross-linked network structures, have been widely used in many fields, such as drug delivery, cartilage repair, waste treatment and electronic equipment. However, the applications of hydrogels are often limited by their poor mechanical properties and self-repairing capability. Currently, the reported tough hydrogels are usually not or only weakly self-repairing, and self-healing hydrogels are usually very weak in mechanical properties. Developing hydrogel materials with both high mechanical strength and selfhealing properties is significant from both academic and industrial points of view. The present paper summarizes the development of tough self-healing hydrogels covering from preparation methods, network structures, to properties. It provides an outlook of the perspective of tough self-healing hydrogels.关键词：Self-healing;Hydrogels;Tough;Cross-linking;Mechanical property
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发布时间：2022-08-31 - 摘要：Ultra-high molecular weight polyethylene (UHMWPE) fibers are widely used in fiber reinforced polymers (FRP) because of their excellent properties. However, UHMWPE fibers inherently exhibit poor adhesion owing to the low surface free energy and the lack of polar functional groups, which affect the performance of the composites and limit their application. Surface modification can effectively increase the interface strength of FRP and thus improve the properties of the materials. In this review, the recent research progress on the surface modification of UHMWPE fibers, with the emphasis on chemical treatment, plasma treatment, corona discharge and radiation-induced surface grafting method, has been summarized, and the development of modification method is prospected.关键词：FRP;UHMWPE;Surface modification;Interface
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发布时间：2022-08-31 - 摘要：DMSO-free and Serum-free cell freezing medium has important application value in the cryopreservation of clinical grade cell products. In this paper, K562 cells were used as model cells to explore the cryoprotective effect of γ-PGA on cells in a DMSO-free and Serum-free system. The RPMI 1640 medium with glycerol content of 10% (v/v) was set as the negative control group, the fetal bovine serum with DMSO content of 10% (v/v) was set as the positive control group, the RPMI 1640 medium with glycerol content of 10% (v/v) and γ-PGA content of 0.01% (w/v) was set as the experimental group. K562 cells were suspended in the above cell freezing medium at a density of 1×106 cells/mL and placed in liquid nitrogen for 10 weeks. After resuscitation, cell recovery rate, cell morphology, and cell expansion ability of K562 were detected to analyze the cryoprotective effect of γ-polyglutamic acid on K562 cells in DMSO-Free and Serum-Free cell freezing medium. The results showed that the cell recovery rate of the experimental group was (83.00±3.00)%, which was significantly higher than that of the negative control group (70.33±5.51)% (p<0.05) and the positive control group (71.00±2.65)% (p<0.05); the morphology of the cells in the experimental group was intact after freezing, the average diameter and roundness of cells were basically the same before and after freezing; the cell viability after culture for 24 h after resuscitation was (88.83 ± 14.29)%, which was significantly higher than that of the negative control group (67.51±5.20)% (p<0.05), and was not significantly different from the (78.75±3.31)% of the positive control group; the lag phase in cell expansion after resuscitation was significantly shortened. It can be seen that the addition of γ-PGA to the glycerol cryopreservation system without DMSO and serum can significantly improve the cryopreservation effect of cells, and has good practical application value.关键词：Cryopreservation;γ-Polyglutamic acid;DMSO-free cell freezing medium;Serum-free cell freezing medium
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发布时间：2022-08-31 - 摘要：The antibacterial micro-nano fiber membrane loaded with zinc oxide (ZnO)/polylactic acid (PLA)/ polycaprolactone (PCL) was prepared by electrostatic spinning technology. And the surface morphology, elementary composition and chemical structure of the composite membrane were characterized by scanning electronic microscope (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR), respectively. The antibacterial performance of the composite membrane was evaluated by the antibacterial experiment. The drug release behavior of the composite membrane in vitro was measured by ultraviolet spectrophotometer. The results showed that ZnO and LAH were successfully mixed into the composite micro-nano fibers by physical blending; Concerning to the antibacterial properties, ZnO/PLA/PCL micro-nano fiber composite membranes exhibited better antibacterial efficiency compared to the PLA/PCL micro-nano fiber composite membranes. When the ZnO content was 10% (wt), the composite fiber membrane had the best antibacterial performance. The drug release performance results showed that the ZnO/PLA/PCL micro-nano fiber composite membrane had good drug release performance.关键词：Electrospinning;Micro-nano fiber;Zinc oxide;PLA;PCL
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发布时间：2022-08-31 - 摘要：To solve the problems that the acrylate macromonomer is often colored during synthetic process and the UVcured film of liquid optical clear adhesive prepared therefrom is easy to turn yellow, a new synthetic route is reported in this paper. A colorless and transparent polybutadiene acrylate macromonomer (PBAM) is synthesized in one-pot using hydroxyl-terminated polybudiene (HTPB), potassium naphthalene, and acryloyl chloride (AC) as raw materials. Subsequentially, liquid optical clear adhesive was prepared through blending PBAM, reactive diluent monomer, and photoinitiator. Finally, a series of colorless and transparent films were prepared through UV-curing process. The structure of PBAM was characterized by GPC, 1H-NMR, and FTIR. The optical properties, yellowing resistance, low temperature resistance of UV-cured films were further studied. The results showed that a colorless and transparent PBAM was successfully synthesized by the new route. The UV-cured films of liquid optical clear adhesive exhibited excellent optical properties and yellowing resistance property. The transmittance of cured films was as high as 98%. After 264 hours of accelerated aging exposure to ultraviolet radiation, the color difference (ΔE ) was below 1.5. In addition, the cured film also presented good low temperature resistance, and it’s glass transition temperature was as low as -30℃.关键词：Liquid optical clear adhesive;Hydroxyl terminated polybutadiene;Polybutadiene acrylate;Yellowing resistance
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发布时间：2022-08-31 - 摘要：The properties of PP/POE blends were studied by neural network. The effect of neural network was verified by the data of orthogonal test design of temperature, proportion and impact strength. The experimental data of 10℃, 20℃ and 30℃ are used for learning and training, and the experimental data of 0℃ are used for testing. At the same time, three kinds of neural network models with different structures are obtained by adjusting different parameters. The results show that neural network has a good effect on the prediction of blending modification. Using neural network method to analyze the data of polymer blending modification can reduce the times of experiments, improve the efficiency of experiments, and quickly complete the product formulation design of blends. The general direction of model parameter adjustment under the network type is obtained, which shows that under the condition of less sample data, less number of hidden layers and neural units can achieve better prediction effect.关键词：POE;PP;Blend modification;Neural network
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发布时间：2022-08-31 - 摘要：Polymer science experiment is the core experiment course of polymer material specialty. Under the guidance of the training requirements of engineering education and certification system talents in colleges and universities, combined with the cutting-edge hot spots in the field, it is the direction of teaching reform to guide students to study independently and design experiments scientifically and reasonably. In this paper, the design of "thermosensitive hydrogel preparation and its dynamic swelling property" is taken as an example. A new experimental teaching reform idea is put forward: teachers choose the forefront of research hotspots, and students form a "research group" . Through the transformation of scientific research experiments into experiments to meet the needs of undergraduate teaching, students' experimental design ability, innovation ability and comprehensive quality have been effectively trained.关键词：Polymer science experiment;Hydrogel;Independent design experiment;Teaching reform
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发布时间：2022-08-31 - 摘要：Taking the undergraduate teaching of polymer materials and engineering in Jianghan University as an example, this paper puts forward a new mode of scientific research quality training for undergraduates based on large-scale instruments. With the help of the advantages of large-scale instruments in the cultivation of scientific research quality training, the establishment of an online database, simulation of large instruments, large-scale instrument operation training, organization of student scientific research team and establishment of diversified assessment system had been introduced to further inspire the learning interest of students. The purpose is to cultivate students'self-learning ability, independent thinking ability, team cooperation ability and innovation ability and so on, and then the comprehensive ability in learning and scientific research of students can be improved using new learning methods and methods, which can provide some reference for the training of high-quality and distinctive applied technical talents.关键词：Large-scale instruments;Scientific research quality;Polymer materials and engineering
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发布时间：2022-08-31 - 摘要：Training engineering and technical talents according to OBE(Outcome-Based Education)educational concept raises new challenges to the formulation of talent training programs and the achievement of talent training objectives. This paper puts forward the tree type divergence process of the reverse construction of talent training program and the tree type convergence way to achieve the goal of talent training. Taking the Polymer Materials and Engineering specialty of Qiqihar University as an example, this paper demonstrates the construction process of the corresponding relationship matrix among training objectives, graduation requirements, target points and curriculum system.关键词：Tree-type training programs;Tree-type training objectives;Outcome-based education
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发布时间：2022-08-31 - 摘要：Polymer Chemistry is one of the five basic courses of chemistry (Inorganic Chemistry, Organic Chemistry, Analytical Chemistry, Physical Chemistry and Polymer Chemistry). It is a compulsory course for students majoring in Chemistry, Polymer Materials & Engineering and Material Chemistry. Controlled/ "living" radical polymerization is a relatively new and important method of polymer synthesis technology, In view of the weak teaching of living radical polymerization in Polymer Chemistry course, this paper discusses the essence and Characteristics of the controlled/" living" radical polymerization from the perspective of teaching, and introduces author’s teaching practice. following the concept of outcome-based education, through learning-centered teaching methods, improves teaching quality.关键词：Polymer chemistry;Living radical polymerization;Curriculum teaching
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发布时间：2022-08-31
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