最新刊期
卷 27 ， 期 6 ， 2014
- 摘要：Recently,preparation of porous ceramics by the pyrolysis of block copolymers has received considerable attention as a new promising method, due to the advantages of facial processibility and flexible adjustment with porous structures. There are two main methods to prepare the silicon-based porous ceramics, one-pot pyrolysis of organic-inorganic block copolymers and copyrolysis of the block copolymer and silicon-based ceramic precursor. These years one-pot pyrolysis was very concerned because of the pore size,shape, orentation and the specific surface area of ceramics,which can be well controlled by the microphase separation of the block copolymer. This paper compares the two methods, reviewing the progress at home and abroad.关键词：Block copolymer;Porous ceramics;Ceramic precursor;Microphase structure
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发布时间：2022-09-18 - 摘要：The application developments of noncovalent modification in the functionalization of carbon nanotubes are described,and the research progress of surfactant modification,π-π stacking interactions between small molecules and carbon nanotubes, surface winding and coating with polymer, wrapping and adsorption of biomacromolecule and filling modification are mainly introduced. Besides,further research work and improving direction of noncovalent functionalization of carbon nanotubes are proposed. The interaction mechanism between different modifiers and carbon nanotubes is discussed. Among them, carbon nanotubes can be noncovalently coated with polymers containing conjugated or aromatic groups by π-π and van der Waals interactions between conjugated or aromatic groups and carbon nanotubes. The polymer functionalized carbon nanotubes have good application foreground in the battery, catalyst, biosensor and electrochemical devices. Additionally,noncovalent modification of carbon nanotubes by biomacromolecule can not only improve water solubility of carbon nanotubes in biological system, but also avoid nonspecific adsorption of proteins, nucleic acids and other biological molecules through reasonable design. Finally, the composite system of specific biological molecules and carbon nanotubes can be obtained.关键词：Noncovalent bond;Carbon nanotubes;Modification;Functionalization
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发布时间：2022-09-18 - 摘要：The chemical oxidative polymerization is a common method for preparation of conducting polyaniline. Aniline oligomers producted in the early stage have important effect on the morphology of the final products. The difference molecular structures of aniline oligomers and their self-assembly are the main reason which leads to different morphologies of the final products. Based on the current formation mechanisms of polyaniline micro/nanostructures, the formation of aniline oligomers and theirs influences on the morphology of polyaniline during the chemical oxidative polymerization process were summarized, the complexity of oligomerizationin the chemical oxidative polymerization and the difficulties existing in the study were also proposed.关键词：Oligoaniline;Chemical oxidative polymerization;Polyaniline;Micro/nanosturcutre;Self-assembly
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发布时间：2022-09-18 - 摘要：Copolymer compatibilizers can improve the macroscopic mechanical properties of incompatible polymer blends by improving compatibility of the two homopolymers. The phase morphology and viscoelasticity of polymer blends are also influenced for the improvement of interfacial properties. In this paper, recent progresses on the mechanism and effect evaluation of copolymer compatibilization together with the morphology-rheology correlation of compatibilized polymer blends under flow have been reviewed. Special emphasis is put on the influence of the molecular structure of copolymer and processing conditions on the microscopic dynamics of structural formation during blending.关键词：Immiscible polymer blend;Copolymer compatibilizer;Morphology;Rheology;Flow field
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发布时间：2022-09-18 - 摘要：The chain extension is an effective way for production and recycling of polyesters. As a new biodegradable polyester, the application of poly (lactic acid) is limited due to its disadvantages of brittleness and lower heat resistance. The chain extension can not only increase the molecular weight of poly(lactic acid),but also endow it with some new features or functions, which can improve its performance and is of great significance to expand its applications. In addition, chain extending to the recycling poly (lactic acid) can also improve its mechanical property, which is a prospect method for the recycling poly (lactic acid) to be reused. In this paper, the type and reaction mechanisms of chain extenders as well as the application of the chain extension modification for poly (lactic acid) are reviewed,and the development trend of relative research is discussed.关键词：Poly(lactic acid);Chain extender;Reactive mechanism;Functionalization;Recycling
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发布时间：2022-09-18 - 摘要：Compared with conventional dressings,nano-antimicrobial dressings fabricated by electrospinning are excellent candidate for wound healing. They have high surface-to-volume ratio and porosity which are excellent for the respiration of cells and protect the wound from bacteria infection, and they can kill bacteria more efficiently by increasing the contact area between antimicrobial drugs and bacteria. Besides,they have the maximum degree of bionic structure of the extracellular matrix which can promote the growth of cell and tissue and accelerate the rate of wound healing. The characteristics and antibacterial properties of electrospun nano-antimicrobial dressings and the application of various matrix materials and antibacterial agents in wound dressing are presented, and the application of electrospun nano-antimicrobial dressing is prospected.关键词：Electrospinning;Wound dressing;Antimicrobial;Wound care
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发布时间：2022-09-18 - 摘要：Gene therapy, as a promising therapeutics to treat genetic or acquired diseases, has received significant attention in the past several decades due to its advantages over traditional therapies. Effective release is the key to the high- level expression of gene. The introduction of degradable group into gene carrier can effectively improve the release efficiency, and small fragment from degradative carrier could be metabolized out of the body more easily, and reduce the cytotoxicity obviously. In this paper, the recent progress of various noval biodegradable polyesters as neotype gene carriers were classified by their structures and preparation methods and were summarized including their transfection efficiencies, cytotoxicities and degradation properties. Further more,the prospect of cationic polyester as gene vector was mentioned.关键词：Degradable polyester;Gene transfection;Transfection efficiency;Cytotoxocity
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发布时间：2022-09-18 - 摘要：The NMR-MOUSE (MObile Universal Surface Explorer) was used for the nondestructive polymeric materials testing. Three components,including crystalline domain, interphase and amorphous domain, of various polyethylenes obtained from different manufacture process and deformed polyethylene pipe were detected by this technique. The results showed that the NMR-MOUSE can be used as on-line polyethylene micro-structure measurement device.关键词：NMR MOUSE;Polyethylene;Inter phase;Solid state NMR
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发布时间：2022-09-18 - 摘要：Maleated 1,2-polybutadiene (MAPB) was melt grafted onto polypropylene (PP) in the presence of dicumyl peroxide (DCP). The MAPB-g-PP were characterized by means of Fourier transformed infrared spectroscopy (FTIR), differential scanning calorimeter (DSC) and thermogravimetry (TG). Then the MAPB-g-PP was applied as interfacial compatibilizer in wood plastic composites (WPC) to evaluate the technical formula via the mechanical properties of WPC. The results demonstrated that MAPB could be grafted onto PP, the crystallization temperature and thermostability were increased. The MAPB-g-PP prepared at 180℃ with MAPB:PP:DCP mass ratio of 13:37:0. 2 showed the best effect on the mechanical properties of WPC.关键词：Polypropylene grafting modification;Maleated 1,2-polybutadiene;Wood/Plastic composite
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发布时间：2022-09-18 - 摘要：The effects of potassium titanate whisker (PTW) on the vulcanized properties,mechanical properties and thermal stabilities of heat vulcanized (HTV) silicone rubber were investigated, respectively. Simultaneously, the fracture surface of the composites and the dispersion degree of PTW were observed by means of scanning electron microscopy (SEM). The results indicated that PTW could accelerate vulcanization reaction, and improve maximum torque(MH) of the compound. The tensile strength, stress at the elongation of 100% and hardness increased with the PTW content. The addition of PTW with relatively low volume fraction to silicone rubber would lead to an increase of the thermal stability sharply,for the composite with 9vol% of PTW,the thermal decomposition temperature increased about 65℃ compared with the pure silicone rubber. The composite with 12vol% of PTW exhibited better thermal stability, the thermal decomposition apparent activation energy E of it was 193. 62kJ/mol, higher than that of the composite with fumed silica.关键词：HTV silicone rubber;Potassium titanate whisker;Thermal stabilities;Vulcanized properties
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发布时间：2022-09-18 - 摘要：A typical atom transfer radical polymerization (ATRP) system for preparing a novel flocculant polyacrylamide with low polydispersity and tacticity was studied in this paper. Lewis acids Y(OTf)3 and AlCl3 were introduced respectively as stereospecific reagent in the ATRP of acrylamide with chloroacetic acid as initiator and CuCl/TMEDA as catalyst. The influence of certain amount of the added Lewis acids on the rate and controllability of polymerization was studied. The participation of the Lewis acid AlCl3 in the polymerization afforded the resultant polyacrylamides with lower polydispersity index 1. 03 and well-controlled tacticity with meso content 76% under the optimum reaction condition used. Kinetic experiments also revealed the polymerization of acrylamide in presence of Lewis acid proceeded with an ATRP process. Furthermore, the obtained flocculants were introduced in the flocculation experiments to testify their flocculation efficiency, which indicated that the flocculation efficiency of the polymer flocculants were dependent upon molecular weight (Mn), polydispersity index (PDI) and meso content (m) of the polymer flocculants. The molecular weight of the flocculants played a critical role in influencing on flocculation efficiency, on the other hand,the narrower of PDI and the higher meso content of the polymer would be beneficial to improving the flocculation efficiency.关键词：Atom transfer radical polymerization(ATRP);Polyacrylamide;Tacticity;Flocculant
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发布时间：2022-09-18 - 摘要：α,ω-dibromo-terminated polystyrenes were prepared by atom transfer radical polymerization(ATRP). Then, the azidation and "click" chemistry reaction were carried out to convert α,ω-dibromo-terminated polystyrenes to α,ω- dialdehyde-terminated telechelic polystyrenes. For comparison, the dialdehyde polystyrene was also prepared by one-step, in which the terminal bromines of the dibromo-terminated polystyrene were directly substituted by p-hydroxy benzaldehyde. The terminal aldehyde functionality of the dialdehyde polystyrene (Mn,NMR = 2480g· mol-1) prepared by the azidation and "click" chemistry reaction could reach 79%,which was 54% higher than the one-step method's. Experimental results also showed that polymers with low-molecular weights were easier to obtain high functionalities than the ones with high molecular weights.关键词：Aldehyde functionalization;Atom transfer radical polymerization (ATRP);Azidation;Click chemistry
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发布时间：2022-09-18 - 摘要：Molecular weight distribution of polyacrylamide(PAM) which is used for flooding is one of the most important indexes for evaluating polymer. Polymer flooding has been important influence on molecular weight distribution of polymer which is used for flooding. At present, the methods on determination of molecular weight distribution have mainly light scattering method, Gel Permeation Chromatography (GPC),GPC coupling technique and rheology method etc. It is introduced these analysis methods and its application range in detail introduction, compared their features and scope and looked the development trend of method and technique. Light scattering method is mainly used for research. GPC method has advantages of simple and high experiment accuracy. GPC coupling technique not only can widen the range of application but also improve the sensitivity. However,the application of molecular weight distribution measurement of GPC still needs to make amount of research. Rheology method has well development because it can save the stage of dissolving polymer; meanwhile, it can resolve the problem of low sensitive which is the polymer owed high molecular weight and long-chain degree of branching.关键词：PAM;Enhanced oil recovery;Molecular weight distribution;Testing and characterization
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发布时间：2022-09-18 - 摘要：At present, the method which blends natural polymeric protein with polymer to fabricate a variety of materials for tissue engineering scaffolds through using electrospinning technique has attracted much attention. Based on this research background, in the paper, two new composite fibers from Silk fibroin (SF)/Collagen (COL)/poly-L-lactide (PLLA) and Silk Fibroin (SF)/Collagen (COL)/poly(L-actic-co-ε-caprolactone) (PLCL) are made by electrospinning. The surface morphologies of composite fibers can be observed by Scanning Electron Microscopy (SEM). The measured results show two new composite fibers have good morphologies and uniform diameters. At the same time, the observed results suggest that their diameter become more and more small while the ratio of the polymeric proteinis varied. Additionally, the mechanical measurements reveal that the mechanical properties improved with the increasing content of polymer in composite fiber membranes. As a result, the tensile properties of the SF/COL/PLCL composite fiber membranes were better than those of SF/COL/PLLA composite fiber membranes.关键词：Electrospinning;SF;COL;PLLA;PLCL;Mechanical properties
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发布时间：2022-09-18 - 摘要：A new type of unsaturated poly (ester-amide) resin was prepared by melt polycondensation and characterized. Some vinyl acetate as crosslinker and benzoyl peroxide and N,N-Dimethylanilline as initiation-accelerant agent,then crosslinking at room temperature and heat treatment to make it depth crosslinked The mechanical and hydrolysis properties of crosslinked unsaturated poly (ester-amide) resin were studied. The results shown as heat treatment temperature, time or crossliner content raised, the mechanical and hydrolysis properties of crosslinked unsaturated poly (ester-amide) resin could be increased observably, but all have the best values.关键词：Unsaturated poly (ester-amide) resin;Mechanical properties;Hhydrolysis properties
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发布时间：2022-09-18 - 摘要：The new collagen /fucoidan films with biological activities were preprated. Its FTIR spectrums were analysed for characterizating forming ionic bonds between collagen and fucoidan. Its anticoagulant activities in vitro and cell proliferation of Human umbilical vein endothelial cells( HUVEC) were appreciated preliminarily by the method of activited partial thromboplastin time (tAPTT)、activited thromboplastin time (tPT)、thrombin time (tTT) and method MTT staining respectively. It is shown that tAPTT 、tTThave Significantly different from the control in different concentration respectively, and tPT has not;the films OD550nm are greater than collagen film, the cell proliferation of HUVEC raises more,the collagen added fucoidan improves HUVEC proliferation.关键词：Collagen;Fucoidan;Anticoagulant;HUVEC;Cell proliferation
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发布时间：2022-09-18 - 摘要：Development of optical grade transparent Bioriented Stretching Polyester (BOPET) film is one of the most important choices for the product structure adjustment in our BOPET industry. The recent progress in master batch preparation of optical transparent BOPET film are mainly reviewed,including through the selection of particles with optimal refraction coefficient and better particle affinity, through the addition of micro and nano particles, and through the addition of third component for copolymerization as well as process modification to prepare high transparent BOPET film. Besides, the future prospects and development situation of optical film industry are outlooked. In the same time,the experimental and theory research on the optical film field is relatively insufficient, and the research suggestions are also put forward.关键词：PET;Composite material;Film;Master Batch;Optical performance
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发布时间：2022-09-18 - 摘要：Graphene is a kind of crystal carbon nanomaterial with two-dimensional structure which has excellent electrical conductivity, mechanical properties. It can be widely applied in nano electronic devices, composite materials and other fields. The preparing methods has attracted much attention in recent years. This paper mainly introduces the chemical preparation methods, which includes oxidation reduction method,epitaxial growth method,chemical vapor deposition method and other methods. At the same time,this paper desicribes the advantages and disadvantages of each methods and stresses the influences on the structure and property of the graphene prepared by the reduction method. This kind of graphene has promising applications.关键词：Graphene;Oxidation reduction;Epitaxial growth
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发布时间：2022-09-18 - 摘要：Packaging engineering is a multidisciplinary subject intersected by materials science and engineering,food science and engineering,mechanical engineering and art. Polymer materials course is one of the basic theoretical lessons. In this paper, the position and role of polymer materials course in packaging engineering education were discussed through analysis the course content relationship among packaging materials science,packaging technology and packaging printing science etc. with polymer materials. And the important contents of polymer materials course were studied based on the knowledge structure and specialty demand for packaging engineering specialty. Several teaching methods were presented according to the weak chemical foundation of students.关键词：Packaging engineering specialty;Polymer materials course;Teaching methods
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发布时间：2022-09-18 - 摘要：The polymer polymerization technology is a degree course for polymer major students. The course teaching purpose is not only to teach the basic knowledge in polymer synthesis process, but also to train the student's independent thinking ability, to help students apply the knowledge to analyze and solve problems, to provide the solving methods and ideas for the difficulties and problems in the future work. In this paper, it puts forward some methods and ideas in the aspect of teaching content and method to improve the student interest for study,and to improve the teaching quality and the student's engineering practice ability, according to the course characteristics and the college teaching guidelines to train the "professional chemical engineer" in the new century.关键词：Polymer polymerization technology;Engineering practice ability;Method;Reform
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发布时间：2022-09-18 - 摘要：To master polymerization process and control is a basic skill for students majored in polymer and relevant field. In this paper, a new-type teaching mode of polymerization process is introduced on the base of course teaching of "polymerization process" and production practical teaching, that is combining the "leaning" of the teaching and "observing" of the practice through simulation experiment,and then upgrading to the integrated design of switch on/off and fault handling of products production, finally forming a new four-in-one teaching mode. It has been found that the new-type teaching mode can help students to improve the abilities of practical operating control in large-scale polymerization process, integrate design in process operation plan and coordinate organization in production.关键词：Polymerization process;Simulation experiment;Integrated design;Exploration;Practice
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发布时间：2022-09-18
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