最新刊期
卷 ， 期 5 ， 2005
- 摘要：This article briefly describes some new approaches to stimuli-sensitive polymeric micelles and hoHow spheres,which were developed in the authors’laboratory in recent years．(1)Self-assembly of component polymers via specific interactions to construct non-covaienfly connected micelles (NCCM)．For example,in water,PCL and PAA formed core-shell particles driven by interpolymer hydrogen bonding．After erosslinking the PAA shell and removing the PCL core,“nanoeages”made of PAA network were obtained．This hollow structure shows perfect reversible size-pH dependence．(2) Simultaneous in-situ polymerization of monomers and self-assembly of the polymers．In this approach,PNIPAM network were formed by radical polymerization covering PCL particles Hollow spheres of PNIPAM network was then obtained by biodegradation of the PCL core．Both the core-shell spheres and hollow spheres show reversible size dependence on temperature change because of PNIPAM undergoing phase transition around 32℃．(3) Complexation-induced mieellization and transition between the micelles and hollow spheres Graft copolymers of hydmxylethyl cellulose (HEC) and PAA were prepared by free radicai polymerization．The copolymers showed pH dependent micellization,i．e．mieelles formed when pH of the graft copelymer solution decreased to around 3．The mieellar structure could be loeked by crosslinking PAA grafts．The resultant cross-linked mieelles undergo pH-dependent transition between the micelles and hollow sphere,which accompanies a remarkable particle size change．Both the micellization and the structure transition were found to be reversible and associated with H-bonding complexation between the main chain and grafts．
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发布时间：2021-03-19 - 摘要：The research progresses in the synthesis,structure,properties and applications of conducting polyaniline (PAn) in Changchun Institute of Applied Chemistry,Chinese Academy of Sciences are outlined．Starting with the successful synthesis of soluble PAn,some basic chemical and structural issues on PAn were elucidated A structural model of doped PAn and a doping mechanism of PAn were pmposed．In addition to the protonic doping of PAn,iodine oxidative doping,light-assisted oxidative doping and K+ -implantation reductive doping of PAn were found and reported．Two PAn-based anti-corrosion coatings with polyurethane and epoxy resin as carriers were exploited．By means of the principle of dopant-induced solubility,phosphonic acids with long poly (ethylene glycol) tails were synthesized as the water soluble dopants for PAn,and with the usage of these dopants,the processability of PAn in aqueous systems was realized．The manufacturing technologies of PAn and its anti-corrosion coatings have passed the pilot trials and are being industrialized．
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发布时间：2021-03-19
Feature Articles
- 摘要：Crew-cut micelles with polystyrene(PS) as shell and cross-linked poly(4-vinyl pyridine)-co-(divinyl benzene) [P(4VP-co-DVB)] as core have been successively prepared by reversible addition fragmentation transfer (RAFT)polymerization of 4VP and DVB with macro transfer agent,dithiobenzoate-terminated PS,PS-C(S) Ph in selective solvent．The linear macro RAFT agent PS-SC(S) Ph was prepared by RAFT polymerization of S using 2-(ethoxycarbonyl)-2-propyl dithiobenzoate (ECPDB) and AIBN as RAFT agent and initiatior．The advantages of this method are the block copolymerization,mieenization and cmsslinking reactions occur in one pot,and higher concentration of the mieelles up to 30％ can be obtained．The stable nano-sized micelles with functional cores were characterized by dynamic and static laser light scattering (DLLS,SLLS),transmission electron micmgraph (TEM), atomic force microscopy (AFM) and NMR etc．
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发布时间：2021-03-19 - 摘要：The fractured surface morphology and the corresponding fractal dimension of poly(vinyl chloride)/methyl methacrylate-butadiene-styrene copolymer (PVC/MBS) blends were investigated by using the secondary electron line method．The results show that the fracture surface or microstructure of nmterlals is not a strict fractal structure,the serf-similarity of the fracture surface only exists in a small range of surveying dimension,and the fractal dimension values for fractured surfaces of different features are difierent from each other The notch impact strength of PVC/MBS blends increased with the increase of the MBS amount and the fractal dimension value dominated by the fractured surface with self-similarity．The relationship be-tween the fracture toughhess of matefials and the fraetal dimension value of fractured surfaces was discussed theoretically．
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发布时间：2021-03-19 - 摘要：When PVC is burning during fire,it will produce a lot of HCI that is harmful to human beings．As the concentration of HCl is the main criterion of the HCl toxicity,it is important to detect the HCl concentration during the PVC fire A fire smoke releasing device and a Fourier transform infrared spectrometer (FTIR) were used to conduct a quantitative on-line analysis on the concentration of HCl in smokes of PVC in a burning process．The results showed that ahhough the concentration of HCl increased slightly when the PVC was on fire．PVC released most of HCl (about 80 percents) before that in the stage of thermal degradation,and the smoke toxicity reached a peak value The phenomena indicated that the release pattern of HCl is quite different from that of CO and CO2 So when the fire is caused by the combustion of PVC,it must be noticed that the worst case will happen before the flame occurs.
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发布时间：2021-03-19 - 摘要：An effective way to improve the thermostability of poly(β-hydroxybutyrate)(PHB) was developed．Maleic anhydride (MAH) was grafted onto PHB by 60Coγcharacterize radiation．1H-NMR,13C-NMR．TGA,DSC and XRD were used to characterize the radiated samples The results of beth 1H-NMR and 13C-NMR are consistent with the successful grafting of MAH monomem onto PHB molecules．The TGA measurements demonstrated that the thennal stability of grafted PHB was measurably improved with the introduction of MAH groups．The 5％ weight loss temporatureof the grafted PHB with a graft degree of 0.52％ was enhanced by 36 K．These significant results suggest that wide commercial application of PHB may be possible The DSC results showed beth the melting temperature and crystallization temperature of the grafting products were decreased Moreover．Lhe erystallinity of the grafted PHB was decreased with the introduction of MAH groups,and the hydmphilie pmporty was impmved.
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发布时间：2021-03-19 - 摘要：The selective laser sintering (SLS) was applied to prepare PAl2/rectorite nanocomposites with blended powders of PAl2 and organic rectorite．Using this technique,the preparation of nanoeomposites and the moulding process are implemented simultaneously．The structure of PAl2/rectofite nanocomposites was characterized by XRD,FT-IR and SEM,and their thermal stability and mechanical properties were also studied The results showed that the organic reetorite was intercalated by PAl2 during the sintering process,and the thermal stability and the mechanical properties such as the tensile strength,flexural strength and impact strength of the PAl2/rectorite nanocomposites weIe better than those of sintered pure PAl2.
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发布时间：2021-03-19 - 摘要：Polysulfone nanofibers were prepared by electrospinning．The electrospinning equipment was designed in a new way,in which the spinneret was combined with a gas jet device．The intrinsic viscosity of the used polysulfone was 0.97 dL/g in dimethyl acetamide,which was also the solvent in electmspinning．The gas used in this gas jet/electrostatic spinning was nitrogen The relationship between the process parameters and the average diameter of polysulfone nanofibers was invesfigaled．The main process parameters studied in this work were the voltage,the flow rate of the spinning fluid,the distance between the spinneret and the nanofiber collector and the temperature in the spinning chamber．The other important factors determining the nanometer diameter were the spinning fluid properties including its viscosity,surface tension and electrical conductivity The average diameter and the diameter distribution of eleetmspinning nanofibers were measured experimentally by using scanning electron mlcmscopy．The diameter of polysulfone nmaofibers prepared by the gas jet/electrostatic spinning was in the range from 50 am to 500 nm．It was found that the diameter of nanofibers was mainly depended on the high voltage,the gap between the spinneret and the collector and the concentration of polymer solutions．As compared to the eouventional eletrospinning the gas jet/electrostatic spinning method could generate thinner and more uniform nanofibers with higher efllciency.
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发布时间：2021-03-19 - 摘要：Poly (vinyl chloride) (PVC)/nano-hydrotalcite composites were obtained by processing PVC/nano- hydrotalcite composite resins prepared by suspension polymerization of vinyl chloride in the presence of hydrotulcite．The morphology and mechanical properties of PVC/nano-hydmtnlcite composites were investigated and compared with those of PVC/nano-hydmtalcite composites prepared by direct melt mixing of PVC and nano-hydrotalcite．It was shown that hydrotalcite particles were dispersed much more homogeneous in PVC composites prepared by the first method．In these composites hydmtaleite particles existed mainly as primary particles of nanoscales with no obvious aggregation．As a result,PVC composites prepared by the first method had better mechanical properties than those prepared by the second method．The tensile strength．Young’s modulus and Charpy impact strength of PVC composite increased with increasing the content of nano-hyarotalcite in a range of less than 5 wt％ The thermal stability of PVC composite resin increased as the weight fraction of nano-hydrotaleite increased．The storage modulus and the loss modulus of PVC/nano-hydrotalcite composites were all slighfly higher than those of the pristine PVC in the temperature region below and around the glass transition．tanδ and glass transition temperature of PVC/nano-hydmtaleite composites were almost as same as those of the pristine PVC.
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发布时间：2021-03-19 - 摘要：The electrochemical and electroluminescent properties of some europium complexes and the terpolymers of 9-vinylearbazole．methyl methaerylate and europium-methacrylate complex were investigated．Cyclic vohammetry measurements of poly(VK-co-MMA-co-Eu(BA)2(MAA)phen)(C1) showed a quasi-reversible oxidation peak with onset of 0.75 V,and an irreversible reduction peak with onset of -1.8V．The msults demonstrated that this kind of multi-functional material has both hole- and electron-transporting properties．Some light-emitting diodes(LEDs) based on the europium containing complex and copolymers were fabricated．All these devices exhibited characteristic sharp red electroluminescence when forward biases were applied,and the turn-on voltage was in the range of 12～27 V．A maximum brightness of 52 cd/m2 with a luminous efficiency of about 0.031 lm/W was achieved from a single-layer device based on the multi-functional eopolymer C3．EL spectra of the devices showed that the emissions were from the corresponding lanthanide-complex units．instead of carbazole groups of the copolymers．It is suggested that the carbazole groups in Cn sewe as hole-transport material while electron transfer may occur thmugh the lanthanide-containing moieties of the same copolymer.
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发布时间：2021-03-19 - 摘要：With deionized water as bore fluid and tap water as extemal coagulant,cellulose hollow fiber membranes (CHFM) were prepared from a dope composed of cellulose/N-methylmorpholine-N-oxide (NMMO)/H2O using a wet spinning process．The prepared CHFM showed dramatic dimension shrinkage after being naturally dried and the resulted dry CHFM possessed a homogeneously dense structure that could ensure the water permeation stability during the humidification process,The swelling performance of CHFM in water at different temperatures was tested and it was proven that increasing temperature would inhibit ceHulose swelling in water．Also its permeation rates in “water-swollen” state for gases such as H2 and O2 were measured that could help to make sure only little gas leakage would happen during the humidification process．Influence of water-gas pressure difference and water temperature on the water permeation flux of CHFM was investigated The results show that the water permeation flux of CHFM increased with both the water-gas pressure difference and water temperature．With water-gas pressure difference at 0.2 MPa and water temperature at 80℃,its water permeation flux could reach as high as 0.63 L/(m2·h)．The preliminary experiments were carried out to test its humidification ability for reacting gases of proton exchange membrane fuel cell (PEMFC)．With the self-made humidification module,the relative humidity of gases could be increased to over 90％ under certain conditions．All these results show that the humidification ability of CHFM is excellent．which means that it is suitable to be used in the humidifieation system for PEMFC.
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发布时间：2021-03-19 - 摘要：Thermo- and pH-sensitive hydrogels were prepared by graft eopolymefization of N-isopropylaerylamide onto chitosan via γ-radiation．The effects of monomer concentration and total irradiation dose on grafting percentage and grafting efficiency were studied The graft copolymers were characterized by”C CP/MAS NMR and the thermo-gravimetric analysis．The pH-and thermo-sensitivity and swelling properties of the hydrogels were investigated．The results showed that the grafting percentage and grafting efficiency increased with the increase of monomer concentration and total irradiation dose．The highest grafting percentage is 620％,the lower critical solution temperature of this hydrogel is about 28℃．
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发布时间：2021-03-19 - 摘要：Different processing methods such as magnetical stirring．high-speed emulsifying and homogenizing and ball milling,were used to homogenously disperse the clay agglomerates and facilitate their exfoliation in epoxy/clay nanocomposites．The mechanical properties and effect of external shearing force on the exfoliation of organic clay modified with organic amine,quaternary ammonium salts and the combination of quatemary ammonium salts and meta-xylylenedianfine (MXDA) were investigated It was found that,for the general stirring,only partially exfaliated stmcture for the small clay particles or the external layers of large clay agglomerates were obtained While the fine exfoliation for the external and central layers can be easily achieved by exerting vigorous shearing force,and the catalytic role of acid primary alkylammonium is not the key influencing the exfoliation of clay in epoxy matrix．The impact strength and flexural strength of epoxy/clay nanocomposites can be dramatically improved,which was about 50％ and 8％ higher that,those of the pristine epoxy．respectively．The degree of exfoiiation of clay particles will be substantially determined by the pulverization of the clay agglomerates The smaller the size of clay particles,the better the dispersion and exfoliation of clay layers ale,and a simultaneous outward shift of the extcrnal and central layers occurs．
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发布时间：2021-03-19 - 摘要：Photosensitive monomers of bisphenol A dieinnamic ester and hexafluorobiphenol A dicinnamate ester were used for preparation of films by photo-crosslinking reaction initiated by irradiation of linearly polarized uhraviolet light．Homogeneous and homeotropic alignments of molecules of a nematic liquid crystal 5CB were obtained on the two resultant films respectively The structure change due to the photo-erosslinking reaction process was revealed by Fourier transform infrared spectra．The surface of these fihns didn’t show clear morphological anisotropy through atomic force microscope analysis．It was found that the surface energy,especially its polar componeut of these aligned films decreased with introduction of the fluorine groups．These results indicated that it was the fluorinated groups that caused the homeotmpic alignment of liquid crystal molecules．
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发布时间：2021-03-19 - 摘要：The Flory-Schrdz distribution or the most probable distribution was deduced in literature．for the molecular weight distribution functions of linear polymers synthesized by condensation and addition reactions in some simple eases．An alternative theoretical way for deducing these equations is given according to the most probable state by using the basic principle in statistical physics for two model systems of typical linear polymers,the forming of which obevs the mechanism of free radical termination by combination and disproportionation Then the Hory-Schulz distribution is obtained quite naturally This theoretical method is simple and easy without any additional supposition．It is hoped that this study could be helpful in understanding the physical foundation of the Flory-Schulz distribution.
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发布时间：2021-03-19 - 摘要：N-phthaloyl chitosan is able to form cholesteric liquid crystalline ohase in concentrated solutions of some organic solvents,including DMF,DMSO,DMAc and pyridine．Circular dichroism was applied to investigate the change of handedness for the above four systems．CD spectra suggested two kinds of absorption peaks when the concentration was highelf than a critical concentration for forming liquid crystalline phase One is a sharp peak at 330 nm,the other is a broad peak with a maximum at about 400～450 nm．However only sharp peak at 330 nm was observed for isotmpic solutions．The sharp peak was induced by the helical conformation of molecular chains,and the broad peak was induced by the cholesterie helices of liquid crystal．Therefore the determination of the critical concentration for N-phthaloyl chitosan solutions by monitoring the very beginning of the appearance of the broad Deak is feasible The critical concentrations measured by CD were 1 wt％ lower than those measured by polarized optical microscopy (POM) for all four solvents used．It means,as a method to measure the critical concentration,CD is more sensitive than POM．Two different ways of sample tilt were used in CD messurements to prove that the linear dichroism and birefringance had no effect on CD signal of cholesteric helices of the liquid crystal．
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发布时间：2021-03-19 - 摘要：WAXD、DSC and polarizing microscopy were used in studies on the structure and morphology of poly- (ethylene terphthalate) (PET)/poly(tfimethylene terephthalate) (PTT) blends．It was found that the PTT/PET blend system was compotable in amorphous regions,and the two components crystallized individually forming their own crystalline phases．The crystallization performance and morphology were dependent on the content of the blend systems．The crystallinity and spherulite size of each components decreased with introduction of the second component．
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发布时间：2021-03-19 - 摘要：A facile method using nano-particles to control the surface structure and the wettability was reported．Three kinds of pofy(vinyl chloride) (PVC) films with different surface structure were prepared by the imprinting of nanosilicas．The wettability studies of these films showed that the contact angle for water was changed from 103°to 65°．then improved to 130°．The PVC film surface was examinated by using a scanning electronic microscope．It was showed that the PVC film surface had nanoholes and nanoprotmdings structure after being imprinted with nanosilicas,and the parallel experiments proved that chloroform and NaOH solutions could not improve the wettability of PVC films．
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发布时间：2021-03-19 - 摘要：Conformational properties and elastic behavior of protein-like chains are investigated using the protein-like lattice model built by Kolinski et al．Here the sequence of (HHPPHPP)x is adopted,and different chain length and different α helical interaction energy are also considered．It is found that the α helical interaction energy directly influences the interior conformation and elastic behavior of protein-like chains in the process of tensile elongation． The chains with large α helical interaction energy have lower energy and less elastic force,and they are more easily to lose contacts and more easily to take the“rod”structure．Moreover. α heheal structure remains unchanged in the process of tensile elongation．In the meantime,the length of chains also influences the conformational properties of chains in the elongation process．The long chains have lower energy,less elastic force,more Helmhaltz energy,and larger number of contacts．However,they are mole difficult to take the“rod” structure．This investigation can help us to understand the interior conformations and elastic behavior of real proteins in the process of elongation．
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发布时间：2021-03-19 - 摘要：A novel catalyst for the copolymerization of CO2 and cyclohexene oxide was prepared by using zinc acetate anhydrous,aluminum isopropoxide and precursor N,N’-bis(2,6-diisopropylphenyl)-2,4-ethyldiimine (BDIE) Comparing with other similar catalytic systems prepared with diethyl zinc,it is of low cost and easy to handle The resulted copolymers were characterized by IR and NMR．Effects of reaction conditions such as reaction time and temperature,CO2 pressure,and catalyst concentration on copolymerization were investigated．A highest catalytic efficiency of 31.6 g Copolymer/g Cat was obtained at 80℃ with catalyst concentration of 0.1 g/mL,BDIE：[Zn-Al]=1：2and CO2 pressureof 2 MPain a 24 hperiodof reaction．
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发布时间：2021-03-19 - 摘要：A new method of preparing high-solid-content and low-viscosity poly(methyl methacrylate/n-butyl acrylate/acrylic acid) emulsion with relative low emulsifier concentration and simple technology was investigated．It contains two steps,i. e.(1) prepare mono-dispersed P(MMA/BA/AA) seeded emulsion with solid content at 50％ and large particle size (480～500 nm) by semi-continuous seeded emulsion polymerization；(2) use the seeded emulsion as medium,sodium dodecyl sulfate as emulsifier,sodium bicarbonate as buffer and ammonia persulfate as initiator to prepare target emulsion by semi-continuous emulsion polymerization The preparing period was about 8 h． The total mass ratio of monomers was MMA：BA=40：60．and the amount of AA was 3.0％ of the total mass of monomers．A series of such emulsions were prepared．in which the highest solid content WaS 72％ with a viscosity of 400 mPa·s at a shear rate of 20 s-1 and the coagulum rate was 0.05％．and the emulsifter concentration of which was 2.1％ of the mass of monomers．The stability during polymerization,particle size,rheology properties,gloss properties etc．of the seeded emulsion and the high-solid-content emulsion were also discussed and compared with the conventional emulsion,which Was prepared with almost the same recipe．The results indicated that the obtained emulsions were bimodal in particle size,the large particle diameter was 500～600 nm and that of the small one was about 80nm．which led to its low viscosity．as well as better glossy properties of films．It is concluded that preparing high-solid-content P(MMA/BA/AA) with this method has the following merits,(1) simple technology,(2) short preparing period,(3) low emulsifier concentration,(4) low viscosity and high gloss value．
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发布时间：2021-03-19 - 摘要：PEO solutions were electrospun under different technological conditions to prepare superfine nanofibers Dispeming morphology of electrospun fibers was characterized by SEM,and crystallization behavior of electmspun fibers was characterized by DSC and XRD Dispersing morphology of electrospun fibers was affected by the solution concentration,the voltage and the distance between two electrodes．In all parameters,the concentration was the key factor Electmspun fibers gradually became fine when the concentration was reduced,and/or the voltage and the distance between two electrodes was increased．The crystallinity of PEO electrospun fibers was lower than that of PEO powders,and the possible mechanism was analysed．
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发布时间：2021-03-19 - 摘要：UHMWPE/nano-SiO2 composite fibers were prepared by the method of adding nano-SiO2 in extracting stage,and the influence of nano-SiO2 on the stmcture and properties of UHMWPE fibers were determined by SEM,sonic orientation,WAXD,DSC,TMA and mechanical measurements．The results showed that nano-SiO2 particles diffused into UHMWPE gel fibers during the extracting stage,and they could be dispersed in hallo-size in UHMWPE fibers Compared to virgin UHMWPE fibers,the orientation and erystallinity of UHMWPE/nano-SiO2 composite fibers remained unchanged,while the crystal size decreased greatly．After incorporating nano-SiO2,UHMWPE fibers became both stiffer and tougher than the virgin ones,especially the fiber modulus,which was increased greatly from 1359.24 cN/dtex to 1505.90 cN/dtex Meanwhile．nano-composite UHMWPE fibers displayed a better thermal and thermomechanieal stability.
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发布时间：2021-03-19 - 摘要：Aqueous two-phase polymerization is that the water-soluble monomers are dissolved in the aqueous solution of another water-soluble polymer and polymerize to form an immiscible aqueous two-phase system of polymer solutions The advantages of the aqueous two-phase polymerization are the lower viscosity and higher monomer concentration of the polymerization system,and such method overcomes the problems of agitation and heat release in homogenous aqueous polymerization．The phase diagram of the PAAm-PEG-H2O aqueous two-phase system was measured by turbidimetry titration The phase separation was found to occur more easily when the temperature was about 55℃ The microgTaph of the product prepared by the aqueous two-phase polymerization showed that the poly-(acrylamide)(PAAm) rich aqueous solution dispersed in the continuous poly(ethylene glycol)(PEG) rich aqueous solution phase as a droplet phase．As the polymerization proceeded,the viscosity of the system increased gradually,the final viscosity of the aqueous two-phase polymerization system was about 1.7 Pa·s,and far lower than that of homogeneous aqueous polymerization system．The viscosity variation with the concentrations of acrylamide,initiator,PEG and emulsifier were investigated．The viscosity of the aqueous two-phase polymerization system increased with increasing of PEG concentration．When the monomer concentration exceeded 1.5 mol/L,the viscosity of the aqueous two-phase polymerization system increased sharply．The initiator concentration showed a little effect on the viscosity of the aqueous two-phase polymerization system．When high emulsifier concentration was used,the viscosity of the aqueous two-phase polymerization system increased sharply．As the polymerization temperature rose,the viscosity of the aqueous two-phase polymerization system decreased at first then increased,it coincided with the results of the phase diagram．
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发布时间：2021-03-19 - 摘要：A series of optically active mesogen-jacketed liquid crystal polymers with nagrow polydispersities(P-1～P-6) were studied by a combination of static and dynamic laser light scattering techniques and viscosity measurements in．THF at 25℃．It is found that THF is a good solvent for the polymers studied．The dependences of the intrinsic viscosity [η] and root mean-square radius of gyration2g>z1/2 of the polymers on weight-average molecular weight Mw are[η]=(2.75±0.05)×10-3 Mw0.78±0.02 and g2>z1/2=(1.53±0.04)x10-2 Mw0.60±0.01 ,respectively,in THF at 25℃．According to Bohdanecky-Bushin’s method based on Yamakawa-Fujii-Yoshizaki’s theory for worm-like chain cylinders,the molar mass per unit contour length ML and the persistence length q were estimated to be(29．8±1.0)×102 nm and (15.4±3.0) nm．respectively．The values of the exponent a of Mark-Houwink-Sakurada equation and q indicate that these liquid crystal polymers of the side-chain type have an extended conformation in dilute solutions as most nlain-chain liquid crystal polymers.
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发布时间：2021-03-19
Research Article
- 摘要：A series of poly(N-isopropylacrylamide-co-methacryloyloxyethyl dimethyloctyl ammonium bromide) [P(NIPAM-co-ADMOAB)] hydrogels were prepared．Theinfluences of the amount of ADMOAB in eopolymefie gels on the swelling behavior were investigated．The deswelling and reswelling kinetics were also studied．Results showed that the equilibrium swelling ratios (ESRs) of copolymeric gels increased with the enhanced ADMOAB content in the composition at temperatures below LCST．and the maximum ESR was 126 compared with a value of 28 for homopolymefic gel P(NIPAM),and the ESR for all copolymeric gels tended to zero independent of the composition when the temperature was above LCST The rate constants in deswelling process increased at first and then decreased with increasing the ADMOAB amount．and the final water retention for copolymeric gels(about1％) was much lower than that of P(NIPAM)(20％)．The swelling ratios during resweUing process increased with the ADMOAB amount,andthe diffusion of waterinto P(NIPAM-co-ADMOAB) gels was found to be a non-Fiekianmode．Thorlsh decreased in saline solutions,swelling ratios for copolrmeric gels were not significantly influenced by ionic strength with NaCl concentration from 0.1 to 0.3 mol/L and higher than those of homopolymeric gels in deionized water with the same swelling time．P(NIPAM-co-ADMOAB) hydmgels can be expected as good candidates for controlled drug delivery systems and separation processes.
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发布时间：2021-03-19 - 摘要：Grafting of maleic anhydride/styrene onto PVDF porous membrane was performed in the presence of supercritical carbon dioxide(SCCO2)as a solvent and swelling fluid．The copolymer of maleic anhydride and styrene (SMA) was grafted onto the out and inner surface of PVDF pores membrane by passing through the membrane pores,which was confirmed by ATR-FTIR and XPS measurements．The SEM photographs of the greedmembrane showed that the membrane structure was hardly changed,except for some jams of the out surface．It was found that the water contact angle of the out surface was reduced more than the inner surface．Themembrane biocompatibifity correspondingto protein adsmpfionwasimproved significantly with the grafting of SMA ontothe surface of the PVDF membrane．The effects of SCCO2 pressure and the comonomer and initiator concentrations were invesgated．
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发布时间：2021-03-19 - 摘要：A reverse saturable absorption material of phthalocyalne indium was prepared by the method of injection molding．From the SEM analysis of the cross section of the sample,we could judge the dispersion of phthalocyalne indium in PMMA matrix A UV-Vis spectrophotometer (UVl240) was used to test the UV-Visible spectrum of sample．The sample showed the typical absorption of Q-region at 620 nm to 730nm wavelength．There was a wide non-resonance area at 480 nm to 570 nm wavelength,and the phenomenon of reverse saturable absorption occurred accordingly An ns/ps Nd：YAG pulsating laser device was used to test the characteristic ryeverse saturable absorption of the sample The limited threshold of the sample reached 68.5 mJ/cm2,its dynamic range was 1.07 and the damage threshold was more than 1200 mJ/cm2．
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发布时间：2021-03-19 - 摘要：Organo-attapulgite was obtained by modifying attapulgite with hexadecyltrimethyl ammonium bromide．A new organo-attapulgite based superabsorbent composite was prepared by polymerization of organo-attapulgite dispersed aerylamide,using N,N’-methylenebisacrylamide as a erosslinker and ammonium porsulfate as an imtiator．The structure,morphology,thermal stability of organo-attapulgite and the composite were characterized by FTIR．XRD,SEM,TEM and TGA,respectively．The results indicated that a nanocomposite was successfully obtained after incorporating organo-attapulglte into the polyaerylamide network．The thermal stability and water absorbencv of the nanoeomposite were improved greatly after the organifieation of attapulgite．Water absorbeneies for the nanocomposite incorporated with 10 wt％ HDTMA-APT in distilled water and in a 0.9 wt％ NaCl solution were 2803 gg-1 and 121 gg-1,respectively．
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发布时间：2021-03-19 - 摘要：A kind of organically modified montmorillonite (OMMT) treated by cetryhrimethyl ammonium bromide (CTAB) was grafted with 4,4'-diphenylmethane diisocyanate (MDI) by it’s hydroxyl group(--OH) acted with isocyanate group (一NCO)．This MDI modified montmorillonite was abbreviated as MOMMT．Thenceforth,the MOMMT was applied to prepare polyurethane(PU)/MOMMT nanocomposites based on poly(propylene glycol),1,4-butanediol and MDI via solution intercalation technology Compared with OMMT,the interlayer spacing of MOMMT was enlarged from 2.07 nm to 2.39 nm．PU chains intervened the galleries between MOMMT layers during solution intercalation．and an intercalated PU/MOMMT nanocomposite was obtained．The tensile strength and tear strength of PU/MOMMT nanoeomposites were higher than those of PU/OMMT nanocomposites．Thermal stability of PU/MOMMT nanocomposites was lower than that of the PU/MMT composite because of the degradation of CTAB and MDI in the first step of thermodegradation,whereas in the second step they exhibited higher thermal stability due to the hish barrier effect of the silicate layers dispersed on the nanometer scale and strong interface interaction between the silicate layers and the PU chains.
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发布时间：2021-03-19
Research Bulletin
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