最新刊期
卷 28 ， 期 12 ， 2015
- 摘要：Amphiphilic polymers with both hydrophilic segments and hydrophobic segments have great potential application as a drug carrier. Because star polymers and hyperbranched polymers possess special topological structures with many active terminal functional groups and large spaces in the core can load more drugs and enhance the solubility and biocompatibility by introducing large amount of hydrophilic groups into the end of polymers, so the star polymers or hyperbranched polymers used as drug carrier have become a research hotspot. This paper summarized some star polymer and hyperbranched polymer drug delivery systems, such as hyperbranched polyglycerol drug carrier system and the star polymer drug carrier based on polycaprolactone. The ways of drug loading and releasing for these polymer drug carrier systems were described.关键词：Hyperbranched amphiphilic polymer;Star amphiphilic polymer;Drug carrier;Drug release
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发布时间：2022-09-18 - 摘要：Inorganic nano-fillers can improve the mechanical properties, water and heat resistance and selective permeability of the modified polyurethane(PU) materials, as well as introduce some other novel features such as antibacterial, electromagnetic shielding, and shape memory. Thus in recent years, the investigation of inorganic nano-filler modified PUs has become one of the frontier hotspots of PU modification research. This paper presents a concise review on the recent research progresses of PU nanocomposites. Following the brief introduction of some primary methods employed for preparation of PU nanocomposites, recent progresses in multifunctional coatings, synthetic leather, biomedical and shape memory materials have been reviewed, with emphasis on the improvement of mechanical properties and the introduction of some functional properties by nano-filler modification, and some future research directions of PU nanocomposite materials have also been briefly prospected.关键词：Polyurethane;Nanocomposite materials;Preparation method;Research progress
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发布时间：2022-09-18 - 摘要：Brush copolymers have received significant attention over the past decade. The structure, size and shape of these copolymers can be accurately controlled in nanoscale, and their unique structure can lead to unusual hierarchical nano-assemblies in bulk and aqueous medium. Especially it can provide an ideal platform for the study of interaction behavior between solvents and polymers. In this article, we review the concepts, classification, preparation, and application of stimuli-responsive brush copolymers. It was found that dramatic property variations would happen due to small external changes of temperature, pH, and ion concentration. Such property could let stimuli-responsive copolymers have attractive applications in the fields of drug delivery, catalysis, synthesis of nanowire, etc.关键词：Brush copolymers;Stimuli-responsive;Controlled/living radical polymerization;Self-assembly
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发布时间：2022-09-18 - 摘要：Polydopamine(PDA), the derivative of 3, 4-dihydroxy-L-phenylalanine which plays the adhesive role in the mussel protein structure, as melanin analogues is widely used in various fields. Even though the mechanism for the polymerlization of PDA is still unclear, it has not prevented PDA from playing crucial roles in various fields. PDA has been given a gift that it can react to form a functional layer on the different material surface owing its strong adhesive and numerous functional groups. The surface of those materials, therefore, can be functionally modified by PDA. Driven by the interest in PDA, in this paper we reviewed the discovery of PDA, the mechanism for the formation of PDA, the PDA functional nanoparticles(including PDA functional metal nano-materials, PDA functional reduced graphene materials, PDA functional magnetic nanoparticles and PDA nanoparticles) and the development prospects of PDA.关键词：Dopamine;Polydopamine;Surface functionalization;Composite material
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发布时间：2022-09-18 - 摘要：Smart hydrogels are one family of polymers that can be swellable but insoluble in water, and this hydrogel system can be responsive to external stimuli in the spontaneous manner. As one family of smart hydrogels, thermosensitive hydrogels exhibit volume phase transition phenomenon with the change of environment temperature. Therefore, the combination of thermosensitive hydrogels with antibacterial agents can impart antibacterial activity to the hydrogels. Such kind of novel smart hydrogels with antibacterial activity is able to discontinuously release antibacterial agents with the change of environmental temperature to thereby prolong service life of antibacterial agents. Thus, they would be applied in many fields, such as biology, pharmaceutics, textile, and so on. In this review, the thermosensitive mechanism of thermosensitive hydrogels was introduced. And research progress in the applications of such thermosenstive composite hydrogels(e.g. polyacrylamide, poloxamer, chitosan, and poly(ethylene glycol)-b-polyester copolymer) in combination with antibacterial agents in the antibacterial field during recent years, were reviewed in detail. Finally, their existing problems and prospects in the current research were putted forward as well.关键词：Hydrogel;Thermosensitive;Antibacterial;Research progress
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发布时间：2022-09-18 - 摘要：Compared with the traditional two-dimensional(2D) cell culture, in vitro three-dimensional(3D) cell culture is much closer to the growth microenvironment of cells. The smart hydrogel has good biocompatibility. The special structure and property of smart hydrogel can mimic the extracellular matrix(ECM) and help us achieve the goal of 3D cells culture. Furthermore, the smart hydrogel also has sensitive response to the external environment stimulus, which can change the cells’ microenvironment and enable us to study cell behaviors in 3D model. In this review, we discuss the smart hydrogel and 3D cell culture, review the different types of smart responsive hydrogel and introduce the influence of 3D scaffold on cell behaviors.关键词：Smart hydrogel;Three-dimensional cell culture;Thermo-responsive;pH-Responsive;Photo-responsive
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发布时间：2022-09-18 - 摘要：LLDPE was prepared by in-situ copolymerization with dual function catalysts, {FeCl2}(where Ar=2,4-C6H3(CH3)2 and 2-Cl-4-CH3C6H3) as oligermerization catalyst and commercial Z-N catalyst as copolymerization catalyst. After characterization of the molecular chain by high resolution13C NMR spectra, it was found that the content and carbon distribution of branch-chain is the same in these two catalyst systems. This LLDPE has both short branch-chain and long branch-chain(≥ C6)and wide molecular weight distribution. By comparison of these two groups by rheology, laser-scattering and GPC, group B has long-branch chains.关键词：In-situ copolymerization;LLDPE;13C-NMR spectroscopy;Rheology;Microstructure
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发布时间：2022-09-18 - 摘要：The isothermal crystallization behaviors of natural eucommia ulmoides gum and synthetic trans-1, 4-polyisoprene were comparatively studied by means of DSC and POM. The results of DSC and POM indicated that EUG and TPI exhibited different nucleation and growth mechanism. EUG was mainly homogeneous nucleation, while TPI was heterogeneous nucleation. Isothermal crystallization behavior of EUG was more sensitive to temperature. When isothermally crystallized at a low temperature(28℃), the crystallization rate of EUG was significantly higher than that of TPI; while when isothermally crystallized at relative higher temperatures(31℃~43℃), the crystallization rate of EUG was less than that of TPI obviously. The crystallization activation energy of EUG(147.2kJ/mol) was higher than that of TPI(114.8kJ/mol). EUG formed mainly β spherulites and TPI was the α and β spherulites coexist when isothermal crystallization from melt at 37℃. In addition, the collision between spherulites appeared early for TPI due to the heterogeneous nucleation.关键词：Isothermal crystallization behavior;DSC;POM;Ucommia ulmoide gum;trans-1;4-Polyisoprene
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发布时间：2022-09-18 - 摘要：The objective of this study was to analyze the structure property of the solid residues and the category of liquid products from wheat straw after depolymerization with sulfuric acid. The results showed that the structure of wheat straw after depolymerization was destroyed to a certain extent, most of hemicellulose was effective removal, but its crystallinity was still high. Product types of wheat straw after depolymerization were quite different and were affected by several factors, including reaction time, temperature and acid concentration and other factors. The major products in liquid of the depolymerized wheat straw were glucose, xylose, arabinose, acetic acid, furfural, and 5-hydroxymethyl furfural. By studying the interactions between the H+ and the structure of hemicellulose, cellulose and lignin, the formation mechanism of products after deploymerization wheat straw with sulfuric acid were proposed.关键词：Wheat straw;Depolymerization;Product;Mechanism
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发布时间：2022-09-18 - 摘要：In the article, Fe3O4/attapulgite/polyvinylalcohol composites were successfully prepared by the method of coprecipitation. Scanning Electron Microscope, FT-IR, XRD were used to make characterizations of properties. The composites had the ability to treat phenol effectively. The best heating temperature was 35℃. With the increase of H2O2 and the prolonging of the laying time, the absorbance decreased. When the dosage of H2O2 was 16mL, and the laying time was 64 h, the efficiency of treatment was 88.3%. At magnetic field, Fe3O4/attapulgite/polyvinylalcohol composites were separated and secondary pollution was decreased.关键词：Phenol;Polyvinylalcohol;Ferroferric oxide;Attapulgite
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发布时间：2022-09-18 - 摘要：s:Hydrolysis kinetics and thermal stability of Ethylene-vinyl acetate copolymers(EVA) and Polyvinyl acetate(PVAc) have been studied comparatively. by using thermal hydrolysis, chemical titration, infrared spectrum, thermogravimetry analysis and Differential scanning calorimetry(DSC). The result shows that the hydrolysis rates of PVAc is about 25~30 times faster than EVA, it is due to the introduction of vinyl chain in the molecular structure of EVA reduces the acetoxy density, and space effect of double bond adjacent to the acetoxy group, making EVA get good hydrolysis stability. At the same time, greatly increasing the thermal stability of the molecular structure. Therefore, PVAc is peculiarly prone to degraded during the long storage process. However, EVA could dramatically improve the long term storage failure of the cartridge.关键词：IR spectrum;Thermogravimetry;Differential scanning calorimetry;Polyvinyl acetate;Ethylene-vinyl acetate copolymers;Hydrolysis
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发布时间：2022-09-18 - 摘要：40% weight of phenol was substituted by oxidatively degradated lignin to formulate foaming phenolic resin at molar ratio of phenol to formaldehyde of 1:1.7. Kinetics of the modified phenolic resin and its curing activity were studied by using isothermal differential scanning calorimeter(DSC) and HAAKE rheometer, respectively. The results showed that temperature had no significant effect on the enthalpy of curing process, and the velocity of curing increased with increasing temperature. The dynamic equation of curing process of the modified phenolic resin was dα/dt=2.83×1017×exp(-125.27×103/RT)(1-α)0.84. The relationship between reaction and time deduced by the equation was almost the same as the real data.关键词：Lignin;Phenolic resin;Differential sacnning calorimeter;Kinetics of the polymerization
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发布时间：2022-09-18 - 摘要：Having the advantages of broad-spectrum antibacterial property, biocompatibility,biodegradability, non-toxicity and no immunogenicity, chitosan has good application prospects in medical materials,oral medicine and traditional Chinese medicine.It aims at promoting the application of chitosan in medical and pharmaceutical areas by reviewing the researches of chitosan in these areas;and more derivatives are being developed with the intensive study,more new materials will be developed,which will promote the development of medical and pharmaceutical industries.The emphasis of this paper was put on the introduction to the preparation,properties and application situations of chitosan in these areas such as medical materials,oral medicine and traditional Chinese medicine,an empirical basis for the expansion of the scope of application of chitosan in medical field is created.关键词：Chitosan;Derivative;Pharmaceutical and medical area;Application
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发布时间：2022-09-18 - 摘要：Polymer reaction engineering is a professional course for the student majored in polymer materials, In the learning process, student will master the basal theory from the angle of the engineering practice. For improving the teaching effect, it is extremely important to give an excellent first class. During the first class, this paper discussed how to give an excellent first class from that the polymer science knowledge framework, the engineering analysis method, the plant practice and polymerization reaction engineering design,and that in view of engineering application analyses industrial scale-up problems and the ideas for the design of stirred polymerization reactor. In the first class, stimulating students’ interests in knowledge engineering lay a good foundation for the teaching of the subsequent course of polymerization reaction engineering.关键词：Polymerization reaction engineering;First class;Teaching method
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发布时间：2022-09-18 - 摘要：The characterization of polymer crosslinking density can be divided into qualitative and quantitative characterization. Low polymer crosslinking density can be quantificationally characterized by the method of simple swelling, while under the condition of smaller deformation, high polymer crosslinking density can be quantificationally characterized by dynamic thermomechanical analysis, polymer crosslinking density can also be quantificationally characterized by measuring glass transition temperature. The qualitative characterization of polymer crosslinking density can be divided into thermal characterization, mechanical property characterization, rheology, chemical characterization method, and functional characterization so on; thereinto, thermal characterization such as dynamic thermomechanical analysis can distinguish the intramolecular crosslinking from the intermolecular crosslinking. The characterization of rheology such as frequency sweep test can effectively control the gel point, which lets the viscous fluid into the gel.关键词：Polymer crosslinking density;Swelling method;Dynamic thermomechanical analysis;Glass transition temperature
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发布时间：2022-09-18
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