最新刊期
卷 30 ， 期 5 ， 2017
- 摘要：Due to the good biocompatibility and biodegradability of hydrogel, as well as its three-dimensional network structure which is similar to the extracellular matrix, the hydrogels have promising potential applications in various fields, such as biomaterial, pharmaceuticals, and biomedical. Rheology describes the flow and mechanical properties of material. The viscoelastic response of hydrogel is sensitive to the change of structure. Therefore,rheology is an important way of analyzing hydrogels. In this review,we summarize the applications of rheology in hydrogels research, introduce the methods of studying rheology of hydrogels, discuss the factors that influence the rheology behaviors of hydrogels,and look forward to the future of hydrogel rheology.关键词：Hydrogel;Rheology;Dynamics;Structure
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发布时间：2022-09-06 - 摘要：UV-curing three-dimensional printing technology is similar to ink-jet printing, which is one of the Rapid Prototyping Manufacturing technologys integrating droplet ejection technology with layered manufacturing technology and using photosensitive resins as the printing materials. It has the advantages in many aspects such as molding precision, processing velocity, molding temperature, equipment operation, equipment maintenance and running cost. Consequently, UV-curing three-dimensional printing has better developing potentialities and expansive applying foreground. This paper briefly reviewed the working principle and development status of the UV-curing three-dimensional printing and evaluated the advantages of this technology. Special interests were focused on the characteristics of UV-curing three-dimensional printing materials and its research progress. Finally, we prospected the printing materials research trends in the future.关键词：UV-Curing three dimensional printing;Rapid prototyping;Jetting materials;Photosensitive resin;Prepolymer
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发布时间：2022-09-06 - 摘要：Chitosan is a natural polymer which is the only cationic alkaline polysaccharide that found so far. It contains reactive functional groups, such as hydroxy and amino. It has excellent properties,such as biocompatibility, microbial degradation,antibacterium, and no cytotoxicity. And it has promising appilcations in many fields, such as biochemistry, medicine,environmental protection and agriculture. However, due to better stereoregularity and stronger hydrogen bonding, chitosan is insoluble in water and other organic solvents except dilute hydrochloric acid and dilute acetic acid, which limits its application scope. In order to expand its application field,the graft copolymerization reaction is usually used to improve the performance of chitosan. In this paper,the latest researches about chitosan graft copolymerization,including free radical initiated grafting, coupling grafting, catalysis grafting are introduced.关键词：Chitosan;Graft copolymerization;Free radical initiated grafting;Coupling grafting;Catalysis grafting
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发布时间：2022-09-06 - 摘要：Research progresses of the effects of inorganic substance on thermal properties of starch plastics are reviewed in recent years. According to different thermal properties which contain glass-transition temperature, rheological property, thermal stability and different inorganic substances,we mainly reviewed the research progresses of effects of inorganic substances including silicate,oxide,hydroxide and metal salt on each thermal property of starch plastics and finally the future development trend is discussed.关键词：Inorganic Substances;Glass-transition Temperature;Rheological Property;Thermal stability
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发布时间：2022-09-06 - 摘要：Epichlorohydrin modified poly ( p-phenylene terephthamide) ( PPTA-ECH ) and poly ( m-phenylene isophthalamide) (PMIA-ECH) were prepared and used as coating agents for PPTA fabric in PPTA fabric/epoxy resin composites. Field emission scanning electron microscopy (FE-SEM),Fourier Transform Infrared Spectroscopy (FTIR), and x-ray photoelectron spectroscopy (XPS) were used to characterize the structure of PPTA-ECH coating on the surface of PPTA fibers. The interlaminar shear strength (ILSS) and in-plane shear strength (ISS) of composites of PPTA-ECH and PMIA-ECH coated PPTA fabric/epoxy resins were investigated, which were compared with that of the pristine PPTA fabric/epoxy resin. The results showed that the coatings of PPTA-ECH and PMIA-ECH can significantly improve the interfacial properties of PPTA fabric with epoxy resins. The ILSS values of PPTA-ECH and PMIA-ECH coated PPTA fabric/epoxy resin composites were increased by 26. 20% and 14. 76% , and the ISS values of them were increased by 26. 98% and 11. 86% , respectively, compared with that of pristine PPTA fabric/epoxy resin. The reinforcement effects of PPTA-ECH on ILSS and ISS are better than those of PMIA-ECH due to the stronger affinity of the former for PPTA fiber. The spreading and adsorption of PPTA-ECH on the surface of PPTA fibers and its reinforcement mechanism for PPTA fabric/epoxy resin composite were discussed. Thus PPTA-ECH has great potential as new coating agent for the fabrication of PPTA materials.关键词：Epichlorohydrin modified PPTA;Composite;Coating agent;ILSS;ISS
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发布时间：2022-09-06 - 摘要：In order to overcome the low shale inhibition property and poor compatibility of the present cationic shale inhibitors, a low molecular weight cationic poly (acrylamide) with hydrophobic modification structures, i. e.,BJX-1, was prepared by precipitation polymerization in ethanol/butyl acetate mixtures. Acrylamide, methacryloxyethyl trimethylammonium chloride, and octadecyl acrylate were selected as the monomers. The factors,such as solvent composition, temperature, initiator concentration, which influence the molecular weight of BJX-1 were studied; the results show that the molecular weight of BJX-1 is significantly influenced by solvent composition, thus the molecular weight of BJX-1 can be adjusted by changing solvent composition; the best shale inhibition result can be achieved by keeping the molecular weight of BJX-1 at 1. 45 × 105g/mol~1. 87 × 105g/mol, the rolling recovery of shale cuttings at 120℃ is about 78%. The rolling recovery of shale cuttings at 120 ℃ could be more than 90% when increases the content of hydrophobic units in BJX-1 to 2~4%. The optimum reaction conditions are: Vethanol: Vbutylacetate = 90: 10~100: 0, 0. 1% of initiator, 3% of monomer,reaction temperature is 80℃,reaction time is 7h. A comparative study on the performances of BJX-1 and the present cationic shale inhibitors in drilling fluids was conducted, the results show that when keep the shale inhibitor addition at 1 % , the rolling recovery of shale cuttings at 120℃ of BJX-1 is 27. 85% and 50. 06% more than the most commonly used cationic compound JA-1 and cationic polymer DY-1. The results indicate that BJX-1 can improve the rheological properties of drilling fluid and make the rheological properties of drilling fluid more stable; BJX-1 can also show good HTHP fluid loss control capability.关键词：Drilling fluids;Inhibitors;Hydrophobic modification;Cationic poly (acrylamide);Rheological properties
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发布时间：2022-09-06 - 摘要：In this paper, nano-Al2O3 was modified by modifier KH570, and the modified Al2O3 was used for the modification of bisphenol A epoxy acrylate. We studied the effect of the mass fraction of the modified nano-Al2O3 (1 % (wt) ~5%(wt))on the properties of the resin. The results showed that the smallest volume shrinkage rate was 6. 48% when the connection of modified nano-Al2O3 was 5 % ( wt) ; the highest gelling percent was 88. 3 % when the mass fraction of modified nano-Al2O3 was 2 %. TGA test results showed that nano-Al2O3 improves the thermal stability of the resin. Tensile results showed that with the increase of the mass fraction of the modified nano-Al2O3,the tensile strength of the composite first increased and then decreased, and the tensile strength was the highest when the mass fraction of modified nano-Al2O3 was 3%(the tensile strength was 34. 74MPa and increased by 108. 27%). The originality of this paper is that, first,we used modifier KH570 to modify the surface of nano-Al2O3 , making it easier to disperse in the resin matrix. Second, this modified photosensitive resin is suitable for 3D printing environment.关键词：UV curing;Nano-Al2O3;Modifier KH570;Bisphenol A epoxy acrylate;3D printing
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发布时间：2022-09-06 - 摘要：A phase-change stored energy microcapsules were prepared by polymerization, in which polystyrene (PS), poly methyl methacrylate (PMMA) or copolymers of styrene and methyl methacrylate were used as shell materials, n-octadecane was used as a core material,and sodium dodecyl benzene sulfonate (SDBS) as a emulsifier. The morphology, phase-change thermal properties and thermal stability of microcapsules, respectively, were characterized by particle size analyzer, transmission electron microscope (TEM),thermogravimetric analyzer (TG) and differential scanning calorimetry (DSC). The results show that the particle size of microcapsules is uniform, the particle dispersion is good, and the shell is well wrapped when the copolymer of styrene (St) and methyl methacrylate (MMA),both mass ratio is 1:5),is used as shell material, and sodium dodecyl benzene sulfonate content is 1. 5g (3% of the total mass). The heat release peaks of microcapsules are at 27. 3℃ of starting temperature, at 31. 9℃ of end temperature, and the phase transformation temperature is 28. 9℃,the phase-change enthalpy of microcapsules is 48. 4J/g. Long-term use temperature should not exceed 131℃ by TG analysis. The microcapsules contain core and shell materials by IR analysis. This octadecane/poly (St- MMA) phase change microcapsules can be used for the material关键词：n-Octadecane;P(St-MMA);Phase-change microcapsules;Preparation;Characterization
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发布时间：2022-09-06 - 摘要：Molecular simulation technology is a mature and potential computer experimental technology. Experimental results can be presented in the form of data and graphics by computer with high-speed and stable graphics processing capabilities and database technology can easily extract and store a variety of molecular models and polymer fragments, that enables students to more easily understand the abstract concept of polymer science and the polymer structure and aggregation structure through the visualization of the three-dimensional graphics. The calculation method of molecular dynamics is based on Newtonian mechanics, and the periodic boundary condition model is established under a certain force field. Through the geometric configuration optimization and dynamic calculation. Also the computing data can obtain micro- phase structure which can not be obtained by ordinary polymer experiment. These enrich the experimental content and open up a new field of polymer science experiments.关键词：Molecular simulations;Polymer science experiments;Aggregation structure;Micro-phase structure
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发布时间：2022-09-06 - 摘要：Green chemistry, which can promote the harmonious development of human and nature, is chemistry. The cultivation of the green chemistry consciousness is a basic requirement to realize the sustainable development of society. Polymer chemistry experiment is a required course for students majoring on polymer materials or materials chemistry direction in polymer field in higher colleges and universty. The required course is very advantageous for students to carry out green chemistry education. It is necessary and feasible for permeation of green chemistry ideas in polymer chemistry experiment teaching. The some measures for teaching methods were presented. The permeation of green chemistry ideas in polymer chemistry experiment teaching can improve students'practical ability and green chemistry consciousness.关键词：Polymer chemistry experiment;Green chemistry teaching;Experiment teaching
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发布时间：2022-09-06 - 摘要：Under the guidance of accreditation standard, the present situation and existing problems of polymer specialty experiments were analyzed. Based on the perspective of accreditation, the reform ideas and methods for the experiment curriculum were put forward. To meet the accreditation requirements and improve students' ability to solve complex engineering problems, the supported graduation requirements of the experimental course were specified. On the basis of the existing experiment content, new experimental projects related to economic and environmental protection were added. The proportion of designing and opening innovative experimental projects was improved. The dynamic evaluation of experimental process was applied. The students' ability to solve complex engineering problems was thus improved,and the sustainable development of the experimental teaching was realized.关键词：Engineering education accreditation;Polymer material and engineering;Polymer specialty experiments
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发布时间：2022-09-06
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