Olefin solution polymerization can be used to obtain high-performance polyolefin materials that cannot be obtained via other polymerization processes.Polyolefin elastomers(POE)are a typical example.Due to cost,only a ...Olefin solution polymerization can be used to obtain high-performance polyolefin materials that cannot be obtained via other polymerization processes.Polyolefin elastomers(POE)are a typical example.Due to cost,only a few linear a-olefins(e.g.,1-butene,1-hexene,and 1-octene)are used as comonomers in solution polymerization in industry.However,a-olefin comonomers with other structures may have different effects on polymerization in comparison with common linear ones.Moreover,the properties of the corresponding materials may differ significantly.In this work,copolymers of ethylene with linear and endcyclized a-olefins are synthesized using a metallocene catalyst.The copolymerization of ethylene with linear a-olefins results in a higher turn-over frequency(TOF)and lower incorporation than copolymerization with end-cyclized a-olefins,which may indicate that end-cyclized a-olefins have a higher coordination probability and lower insertion rate.In this reaction,the comonomer is distributed randomly in the polymer chain and efficiently destroys crystallization.End-cyclized a-olefins exhibit a much stronger crystallization destructive capacity(CDC)in the copolymer than linear a-olefins,possibly because linear a-olefins act mainly in the radial direction of the main chain of the polymer,while end-cyclized a-olefins act mainly in the axial direction of the main chain.展开更多
Bonded type RE3+ doped luminescent co-polymer was synthesized by solution free radical copolymerization. The influence of charge sequence, monomers and co-polymerized method on properties and structures of the co-poly...Bonded type RE3+ doped luminescent co-polymer was synthesized by solution free radical copolymerization. The influence of charge sequence, monomers and co-polymerized method on properties and structures of the co-polymers was studied. The emission intensity of the co-polymers at different RE3+ concentrations was tested. The results showed that the co-polymers of Eu-PSt and Eu-PMMA both had wide absorption peak at 200-400 nm and the strongest peak appeared at 235 nm. The fluorescent intensity of Eu3+ doped polystyrene co-polymer was stronger than that of Eu3+ doped PMMA copolymer. The characteristic emission of europium ions was observed in the co-polymers. The copolymer doped with rare earth elements showed the "sensitization effect" for the central ions. The bonded-type rare earth copolymer not only enhanced the energy transfer efficiency, but also improved the fluorescence intensity by increasing the rigidity of main and side chain.展开更多
In this paper, the capabilities of grafting acrylonitrile （AN） onto starch initiatedby Fe（III）-TU, V（V）-TU, Cr（VI）-TU, Mn（VII）-TU redox systems were compared in thepresence of sulfuric acid of different conc...In this paper, the capabilities of grafting acrylonitrile （AN） onto starch initiatedby Fe（III）-TU, V（V）-TU, Cr（VI）-TU, Mn（VII）-TU redox systems were compared in thepresence of sulfuric acid of different concentrations. It was shown that the grafting capabili-ty of Mn（VII）-TU is the highest in these initiating systems. Using Mn (VII-TU as initia-tor, the effects of various acids （HClO<sub>4</sub>, H<sub>2</sub>SO<sub>4</sub>, HNO<sub>3</sub>, HCl） on the graft copolymerizationof acrylonitrile onto starch were discussed, and the capabilities of graft copolymerizationof methyl methacrylate （MMA）, acrylamide （AM）, acrylic acid （AA） onto starch wereinvestigated. The experimental results show that the order of the influences of differentacids is HClO<sub>4</sub>】H<sub>2</sub>SO<sub>4</sub>】HNO<sub>3</sub>】HCl, and the order of grafting capabilities of differentmonomers grafted onto starch is MMA】AN】AM】AA. The structure and morphology ofgraft copolymers were studied with infrared spectroscopy and scanning electron microscopy.The size, shape and roughness of surface of the grafted starch granules are changed aftergrafting.展开更多
Mimicry of nature drives the development of bionic materials.Bionic superhydrophobic materials are a kind of high-efficiency materials to handle oil spills and water pollution.However,the stability of surface coatings...Mimicry of nature drives the development of bionic materials.Bionic superhydrophobic materials are a kind of high-efficiency materials to handle oil spills and water pollution.However,the stability of surface coatings of the superhydrophobic materials remains a challenge.Herein,a new category of self-assembly bionic superhydrophobic surface coating was prepared via one-step condensation/copolymerization of vinyltriethoxysilane(VTES)and divinylbenzene(DVB),which realized the close combination of covalent bonds between organic(e.g.DVB)and inorganic matter(e.g.VTES),and avoided the swelling of polydivinylbenzene(PDVB)in the process of collection of oil from water.This organic-inorganic hybrid polymer could self-assembly deposit on the surface of sponge even other substrates.For example,P(VTES-DVB)-Si0_(2)/MS obtained by assembling P(VTES-DVB)-Si0_(2)on the surface of Melamine Sponge(MS)exhibited superhydrophobicity with a Water Contact Angle(WCA)of 157.3,the optimal adsorption capacity of 77 g g 136 g g-1 for diverse oils,and an excellent separation efficiency of 99.3%.Besides,the excellent acid and alkali resistance of P(VTES-DVB)-Si0_(2)/MS suggested the potential value in practical oil-water separation.P(VTES-DVB)-Si0_(2)showed the outstanding hydrophobic performance by using as coating on different substrates.This work provided a new idea about the stable combination of organic and inorganic matter in the surface modification.展开更多
Emulsion copolymerization of styrene and ethylene catalyzed by a series of neutral nickel(Ⅱ) complexes was carried out in an aqueous system to give high-molecular-weight copolymers.The copolymers and emulsions were c...Emulsion copolymerization of styrene and ethylene catalyzed by a series of neutral nickel(Ⅱ) complexes was carried out in an aqueous system to give high-molecular-weight copolymers.The copolymers and emulsions were characterized by an array of techniques including NMR,GPC,TEM,WAXD and DSC.The results indicate that the copolymers obtained are mostly block copolymers of polyethylene with random insertion of styrene units,and their M_W is in the range of 10~5-10~6.By enhancing the electron withdrawing of th...展开更多
Copolymerization of propylene and hindered piperidine monomers was carried out overa high activity supported Ziegler-Natta catalyst, using Al（C<sub>2</sub>H<sub>5</sub>）<sub>3</sub&g...Copolymerization of propylene and hindered piperidine monomers was carried out overa high activity supported Ziegler-Natta catalyst, using Al（C<sub>2</sub>H<sub>5</sub>）<sub>3</sub> as cocatalyst. Factorswhich affect the copolymerization were studied. The copolymers exhibited high light sta-bility without adding extra light stabilizers. A self-stabilized polypropylene was prepared.展开更多
Ring opening copolymerization of succinic anhydride （SA） with ethylene oxide （EO）was successfully carried out by using a series of aluminum-based catalyst in 1,4-dioxane at62±2℃. The results showed that in-s...Ring opening copolymerization of succinic anhydride （SA） with ethylene oxide （EO）was successfully carried out by using a series of aluminum-based catalyst in 1,4-dioxane at62±2℃. The results showed that in-situ AlR<sub>3</sub>-H<sub>2</sub>O （R=ethyl, iso-butyl） catalysts gavehigher molecular weight （M<sub>w</sub>～10<sup>4</sup>）, while Al（OR）<sub>3</sub> catalysts gave the higher alternatingcopolymer structure with slightly lower molecular weight. The in-situ AlR<sub>3</sub>-H<sub>2</sub>O systemshave been evaluated in more detail for the reaction which showed the optimum H<sub>2</sub>O/Almolar ratio to be 0.5. The copolymers with different composition (F<sub>SA</sub>/F<sub>EO</sub>= 36/64to 45/55 mol/mol) were synthesized by using different monomer feed ratio. The melt-ing point （T<sub>m</sub>）, glass transition temperature （T<sub>g</sub>） and enthalpy of fusion （ΔH<sub>f</sub>） of thesecopolymers are depended on the copolymer composition and in the range of 87～102℃,-12～-18℃, and 37～66J/g, respectively. The second heating scan of DSC also in-dicated that the higher alternating copolymer was more easily recrystallized. The onsetdecomposition temperature was more than 300℃ under nitrogen and influenced by thecopolymer composition.展开更多
i-PP/m-EPR reactor alloy were prepared through ethylene/propylene slurry copolymerization catalyzed by metallocene(rac-Et(Ind)_2ZrCl_2)supported on porous iPP particles.Polar monomer(dihydromyrcene alcohol)treated wit...i-PP/m-EPR reactor alloy were prepared through ethylene/propylene slurry copolymerization catalyzed by metallocene(rac-Et(Ind)_2ZrCl_2)supported on porous iPP particles.Polar monomer(dihydromyrcene alcohol)treated with triethyaluminum was added in the preparation of porous iPP particles to introduce hydroxyl groups and thus enhance the ability for chemically supporting the metallocene catalyst.The effects of MAO/Zr ratio and monomer composition in feed on the reaction activity and property of polymer wer...展开更多
2,2,3,3,4,4,5,5-Octafluoropentyl acrylate was grafted onto silk fiber in a two-step heterogeneous system through the vinyl bonds of acryloyloxyethyl isocyanate modified on the silk.The grafted copolylner was analyzed ...2,2,3,3,4,4,5,5-Octafluoropentyl acrylate was grafted onto silk fiber in a two-step heterogeneous system through the vinyl bonds of acryloyloxyethyl isocyanate modified on the silk.The grafted copolylner was analyzed by FTIR and WAXD,and the results revealed that the fluoroacrylate was successfully grafted onto silk fiber and the crystalline structure of silk fibroin withβ-sheet structure was not changed after graft copolymerization.The FT-IR corrected method was used to simulate the grafting yield onto ...展开更多
Lignin isolated from enzymatic hydrolyzed corn-stalks (EH-lignin) is a renewable natural polymer noted for its versatility and applicability in a vari-ety of uses. Graft copolymerization of EH-lignin with acrylamide (...Lignin isolated from enzymatic hydrolyzed corn-stalks (EH-lignin) is a renewable natural polymer noted for its versatility and applicability in a vari-ety of uses. Graft copolymerization of EH-lignin with acrylamide (AM) and the application of this copolymer as a flocculant in dye wastewater treatment were studied in this article. The influ-ences of some factors on yield of copolymer and the grafting ratio were investigated and the structure of EH-lignin/AM graft copolymer was characterized by FT-IR. According to the yield and the grafting ratio, the optimum conditions for graft copolymerization were as follows: initiator K2S2O8-Na2S2O3 with a quantity 3 wt% of EH-lignin, mass ratio of AM to EH-lignin was 2~3, reaction time 4h and temperature at 50℃. It was found that the absorption capacity of graft copolymer to two azo-dyes was enhanced with the increase of grafting ratio. Furthermore, the residue concen-tration of EH-lignin/AM graft copolymer remained in the supernatant after flocculation was much lower than that of pure EH-lignin.展开更多
Recyclable polymers offer a great opportunity to address the environmental issues of plastics.Herein,functionalization of recyclable polymers,poly((R)-3,4-trans six-membered ring-fused GBL)(P((R)-M)),were reported via...Recyclable polymers offer a great opportunity to address the environmental issues of plastics.Herein,functionalization of recyclable polymers,poly((R)-3,4-trans six-membered ring-fused GBL)(P((R)-M)),were reported via end-group modifications and block/random copolymerizations.Di-n-butylmagnesium was selected to catalyze ring-opening polymerization(ROP)of(R)-M in the presence of a series of functional alcohols as the initiators.Block/random copolymerizations of(R)-M andε-caprolactone(ε-CL),L-lactide(L-LA)and trimethylene carbonate(TMC)were performed to control the onset decomposition temperature(T_(d)),melting temperature(T_(m))and glass transition temperature(T_(g)).These functionalized recyclable polymers would find broad applications as the sustainable plastics.展开更多
Ethylene/1-hexene was copolymerized by an unbridged zirconocene, (2-PhInd)2ZrCl2/MAO (methyl aluminoxane) at 0 °C and 50 °C respectively. High copolymerization activity and 1-hexene incorporation were observ...Ethylene/1-hexene was copolymerized by an unbridged zirconocene, (2-PhInd)2ZrCl2/MAO (methyl aluminoxane) at 0 °C and 50 °C respectively. High copolymerization activity and 1-hexene incorporation were observed at 0 °C, with the co- polymer formed having random sequence distribution and narrow molecular weight distribution. Ethylene polymerization at 50 °C showed high activity, but copolymerization at 50 °C showed much lower activity, which decreased sharply with increasing 1-hexene concentration in the monomer feed. Copolymer formed at 50 °C showed blocky sequence distribution and broad mo- lecular weight distribution. A mechanism model based on ligand rotation hindered by the propagation chain has been proposed to qualitatively explain the observed phenomena.展开更多
（CpCH<sub>2</sub>CH<sub>2</sub>CH = CH<sub>2</sub>）<sub>2</sub>MCl<sub>2</sub>（M=Zr, Hf）/MAO and Cp<sub>2</sub>ZrCl<sub>2</sub>/M...（CpCH<sub>2</sub>CH<sub>2</sub>CH = CH<sub>2</sub>）<sub>2</sub>MCl<sub>2</sub>（M=Zr, Hf）/MAO and Cp<sub>2</sub>ZrCl<sub>2</sub>/MAO （Cp=cyclopentadienyl; MAO=methylaluminoxane） catalyst systems have been compared for ethylene copolymerization to investigate the influence of theligand and transition metal on the polymerization activity and copolymer properties. For both CH<sub>2</sub>CH<sub>2</sub>CH=CH<sub>2</sub> substitutedcatalysts the catalytic activity decreased with increasing propene concentration in the feed. The activity of the hafnocenecatalyst was 6～8 times lower than that of the analogous zirconocene catalyst, <sup>13</sup>C NMR analysis showed that the copolymerobtained using the unsubstituted catalyst Cp<sub>2</sub>ZrCl<sub>2</sub> has greater incorporatien of propene than those produced byCH<sub>2</sub>CH<sub>2</sub>CH=CH<sub>2</sub> substituted Zr and Hf catalysts. The melting point, crystallinity and the viscosity-average molecularweight of the copolymer decreased with an increase of propenc concentration in the feed. Both CH<sub>2</sub>CH<sub>2</sub>CH= CH<sub>2</sub> substitutedZr and Hf catalysts exhibit little or no difference in the melting point and crystallinity of the produced copolymers. However,there are significant differences between the two zirconocene catalysts. The copolymer produced by Cp<sub>2</sub>ZrCl<sub>2</sub> catalyst havemuch lower T<sub>m</sub> and X<sub>c</sub> than those obtained with the （CpCH<sub>2</sub>CH<sub>2</sub>CH=CH<sub>2</sub>）<sub>2</sub>ZrCl<sub>2</sub> catalyst. The density and molecular weightof the copolymer decreased in the order: （CpCH<sub>2</sub>CH<sub>2</sub>CH=CH<sub>2</sub>）<sub>2</sub>HfCl<sub>2</sub>】（CpCH<sub>2</sub>CH<sub>2</sub>CH=CH<sub>2</sub>）<sub>2</sub>ZrCl<sub>2</sub>】Cp<sub>2</sub>ZrCl<sub>2</sub>. The kineticbehavior of copolymerizaton with Hf catalyst was found to be different from that with Zr catalyst.展开更多
The copolymerization of dibenzofuran(DBF)and 3-methylthiophene(MET)was successfully achieved electrochemically by direct anodic oxidation of the monomer mixtures in boron trifluoride diethyl etherate.The effects of ap...The copolymerization of dibenzofuran(DBF)and 3-methylthiophene(MET)was successfully achieved electrochemically by direct anodic oxidation of the monomer mixtures in boron trifluoride diethyl etherate.The effects of applied polymerization potential and the monomer concentration ratios on the copolymerization were investigated by linear sweep voltammetry and cyclic voltammetry(CV).The structure of copolymer films were investigated by UV-Vis,infrared spectroscopy,thermal analysis.As-formed novel copolymers ...展开更多
In homogeneous media, N,N-Dimethylacrylamide (DMA) was grafted copolymerization to cellulose by a metal-catalyzed atom transfer radical polymerization (ATRP) process. First, cellulose was dissolved in DMAc/LiCl system...In homogeneous media, N,N-Dimethylacrylamide (DMA) was grafted copolymerization to cellulose by a metal-catalyzed atom transfer radical polymerization (ATRP) process. First, cellulose was dissolved in DMAc/LiCl system, and it reacted with 2-bromoisobutyloyl bromide (BiBBr) to produce macroinitiator (cell-BiB). Then DMA was polymerized to the cellulose backbone in a homogeneous DMSO solution in presence of the cell-BiB. Characterization with FT-IR, NMR, and GPC measurements showed that there obtained a graft copolymer with cellulose backbone and PDMA side chains (cell-PDMA) in well-defined structure. The proteins adsorption studies showed that the cellulose membranes modified by the as-prepared cell-PDMA copolymer owns good protein adsorption resistancet.展开更多
The monomer methacrylamido propyl trimethy ammonium chloride( MAPTAC) was copolymerized onto the fiber surface of polypropylene( PP) nonwoven fabric under ultroviole radiation. The weak acid red GN dye adsorption and ...The monomer methacrylamido propyl trimethy ammonium chloride( MAPTAC) was copolymerized onto the fiber surface of polypropylene( PP) nonwoven fabric under ultroviole radiation. The weak acid red GN dye adsorption and adsorptive filtration performance of the resulted PP fabrics were investigated.The results showed that the grafting copolymerization preferred to happen in the inner layer of the fabrics. The water flux of the grafted fabrics decreases with the increase of grafting yield. The collapse of the grafted polymer chains causes the flux increase in acidic condition,or vice versa at alkaline version. The coiling of the polyelectrolyte chains upon the dye adsorption seems to violate the routine assumption of the rigid substrate, and this gets the adsorption energy constant negative. The static adsorption process follows the Lagergren's pseudo-second order kinetic equation. The removals of circa( ca.) 100% of the total permeation volume3 500 mL simulated dye wastewater was reached during permeation.The dye adsorbed fabrics were regenerated by the mixed media of the cationic surfactant / ethanol /water. The grafted fabric assumes stable fabric integrity and stability during permeation,and presents excellent dye adsorption capacity,easy desorption, and repeatable utilization.展开更多
Radical copolymerization of N-phenylmaleedde with cyclohexene was carried out with 2, 2’ -azobisisobutyronitrile in various solvents at 60℃. The copolymer was characterized by IR and
The electrochemical copolymerization of aniline and N,N,N'-trimethylthionin (azure B) in aqueous solutions has been carried out using the potential sweep method. The optimum conditions for the coelectrodeposition ...The electrochemical copolymerization of aniline and N,N,N'-trimethylthionin (azure B) in aqueous solutions has been carried out using the potential sweep method. The optimum conditions for the coelectrodeposition are that the pH value and the temperature of the electrolytic solution are controlled at 5.57 and 30℃, respectively, and the scan potential range is set between -0.25 and 1.10 V (versus SCE). The copolymerization rate of aniline and azure B is about 3 times larger than that of aniline in the absence of azure B. The copolymerization of aniline and azure B was verified from the results of visible spectra during electrolysis, FTIR spectra and the atomic force microscopy (AFM) images of the polymers. The in situ visible spectrum for the electrolysis of the solution containing aniline and azure B is different from that of the respective aniline and azure B. The FTIR spectrum of the copolymer is not a superposition of that of polyaniline and poly(azure B). The AFM image of the copolymer is different from those of polyaniline and poly(azure B) and is not a mixture of individual polymers. The conductivity of the copolymer synthesized at pH 5.57 is four orders of magnitude higher than that of polyaniline synthesized under the same conditions, but in the absence of azure B. The electrochemical properties of the copolymer are mainly attributed to polyaniline, but the copolymer has a better electrochemical reversibility and a much faster charge transfer than those of polyaniline.展开更多
The copolymerization of 2-hydroxyethyl acrylate （HEA, M<sub>1</sub>） and methylmethacrylate （MMA, M<sub>2</sub>） in cyclohexanone was studied. The multiple experiments ofsolution copolymeri...The copolymerization of 2-hydroxyethyl acrylate （HEA, M<sub>1</sub>） and methylmethacrylate （MMA, M<sub>2</sub>） in cyclohexanone was studied. The multiple experiments ofsolution copolymerization with low conversion were carried out at two sensitive compositionfeed points at 60, 80, 100, 120 and 140℃, respectively. The composition of the copolymerswas analyzed by <sup>1</sup>H-NMR. The reactivity ratios which were estimated by the Error-in-Variable Method （EVM） of Mayo-Lewis equation were found to be r<sub>1</sub> = 0.328, r<sub>2</sub> = 1.781for 60℃; 0.375, 1.709 for 80℃; 0.406, 1.654 for 100℃; 0.439, 1.540 for 120℃ and 0.455,1.400 for 140℃, and the 95% joint confidence intervals of the reactivity ratios were alsodetermined. According to r<sub>1</sub> and r<sub>2</sub>, Arrhenius relations and the activity energy differencebetween the homo- and cross-propagation were calculated.展开更多
文摘Olefin solution polymerization can be used to obtain high-performance polyolefin materials that cannot be obtained via other polymerization processes.Polyolefin elastomers(POE)are a typical example.Due to cost,only a few linear a-olefins(e.g.,1-butene,1-hexene,and 1-octene)are used as comonomers in solution polymerization in industry.However,a-olefin comonomers with other structures may have different effects on polymerization in comparison with common linear ones.Moreover,the properties of the corresponding materials may differ significantly.In this work,copolymers of ethylene with linear and endcyclized a-olefins are synthesized using a metallocene catalyst.The copolymerization of ethylene with linear a-olefins results in a higher turn-over frequency(TOF)and lower incorporation than copolymerization with end-cyclized a-olefins,which may indicate that end-cyclized a-olefins have a higher coordination probability and lower insertion rate.In this reaction,the comonomer is distributed randomly in the polymer chain and efficiently destroys crystallization.End-cyclized a-olefins exhibit a much stronger crystallization destructive capacity(CDC)in the copolymer than linear a-olefins,possibly because linear a-olefins act mainly in the radial direction of the main chain of the polymer,while end-cyclized a-olefins act mainly in the axial direction of the main chain.
基金Project supported by the Special Funds for Major State Research Projectsthe National Natural Science Foundation of China (50373034)
文摘Bonded type RE3+ doped luminescent co-polymer was synthesized by solution free radical copolymerization. The influence of charge sequence, monomers and co-polymerized method on properties and structures of the co-polymers was studied. The emission intensity of the co-polymers at different RE3+ concentrations was tested. The results showed that the co-polymers of Eu-PSt and Eu-PMMA both had wide absorption peak at 200-400 nm and the strongest peak appeared at 235 nm. The fluorescent intensity of Eu3+ doped polystyrene co-polymer was stronger than that of Eu3+ doped PMMA copolymer. The characteristic emission of europium ions was observed in the co-polymers. The copolymer doped with rare earth elements showed the "sensitization effect" for the central ions. The bonded-type rare earth copolymer not only enhanced the energy transfer efficiency, but also improved the fluorescence intensity by increasing the rigidity of main and side chain.
文摘In this paper, the capabilities of grafting acrylonitrile （AN） onto starch initiatedby Fe（III）-TU, V（V）-TU, Cr（VI）-TU, Mn（VII）-TU redox systems were compared in thepresence of sulfuric acid of different concentrations. It was shown that the grafting capabili-ty of Mn（VII）-TU is the highest in these initiating systems. Using Mn (VII-TU as initia-tor, the effects of various acids （HClO<sub>4</sub>, H<sub>2</sub>SO<sub>4</sub>, HNO<sub>3</sub>, HCl） on the graft copolymerizationof acrylonitrile onto starch were discussed, and the capabilities of graft copolymerizationof methyl methacrylate （MMA）, acrylamide （AM）, acrylic acid （AA） onto starch wereinvestigated. The experimental results show that the order of the influences of differentacids is HClO<sub>4</sub>】H<sub>2</sub>SO<sub>4</sub>】HNO<sub>3</sub>】HCl, and the order of grafting capabilities of differentmonomers grafted onto starch is MMA】AN】AM】AA. The structure and morphology ofgraft copolymers were studied with infrared spectroscopy and scanning electron microscopy.The size, shape and roughness of surface of the grafted starch granules are changed aftergrafting.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.22008092,21822807 and 51803080)Postgraduate Research&Practice Innovation Program of Jiangsu Prov ince(KYCX19_1592)Science and Technology Planning Social Development Project of Zhenjiang City(SH2020003).
文摘Mimicry of nature drives the development of bionic materials.Bionic superhydrophobic materials are a kind of high-efficiency materials to handle oil spills and water pollution.However,the stability of surface coatings of the superhydrophobic materials remains a challenge.Herein,a new category of self-assembly bionic superhydrophobic surface coating was prepared via one-step condensation/copolymerization of vinyltriethoxysilane(VTES)and divinylbenzene(DVB),which realized the close combination of covalent bonds between organic(e.g.DVB)and inorganic matter(e.g.VTES),and avoided the swelling of polydivinylbenzene(PDVB)in the process of collection of oil from water.This organic-inorganic hybrid polymer could self-assembly deposit on the surface of sponge even other substrates.For example,P(VTES-DVB)-Si0_(2)/MS obtained by assembling P(VTES-DVB)-Si0_(2)on the surface of Melamine Sponge(MS)exhibited superhydrophobicity with a Water Contact Angle(WCA)of 157.3,the optimal adsorption capacity of 77 g g 136 g g-1 for diverse oils,and an excellent separation efficiency of 99.3%.Besides,the excellent acid and alkali resistance of P(VTES-DVB)-Si0_(2)/MS suggested the potential value in practical oil-water separation.P(VTES-DVB)-Si0_(2)showed the outstanding hydrophobic performance by using as coating on different substrates.This work provided a new idea about the stable combination of organic and inorganic matter in the surface modification.
文摘Emulsion copolymerization of styrene and ethylene catalyzed by a series of neutral nickel(Ⅱ) complexes was carried out in an aqueous system to give high-molecular-weight copolymers.The copolymers and emulsions were characterized by an array of techniques including NMR,GPC,TEM,WAXD and DSC.The results indicate that the copolymers obtained are mostly block copolymers of polyethylene with random insertion of styrene units,and their M_W is in the range of 10~5-10~6.By enhancing the electron withdrawing of th...
文摘Copolymerization of propylene and hindered piperidine monomers was carried out overa high activity supported Ziegler-Natta catalyst, using Al（C<sub>2</sub>H<sub>5</sub>）<sub>3</sub> as cocatalyst. Factorswhich affect the copolymerization were studied. The copolymers exhibited high light sta-bility without adding extra light stabilizers. A self-stabilized polypropylene was prepared.
文摘Ring opening copolymerization of succinic anhydride （SA） with ethylene oxide （EO）was successfully carried out by using a series of aluminum-based catalyst in 1,4-dioxane at62±2℃. The results showed that in-situ AlR<sub>3</sub>-H<sub>2</sub>O （R=ethyl, iso-butyl） catalysts gavehigher molecular weight （M<sub>w</sub>～10<sup>4</sup>）, while Al（OR）<sub>3</sub> catalysts gave the higher alternatingcopolymer structure with slightly lower molecular weight. The in-situ AlR<sub>3</sub>-H<sub>2</sub>O systemshave been evaluated in more detail for the reaction which showed the optimum H<sub>2</sub>O/Almolar ratio to be 0.5. The copolymers with different composition (F<sub>SA</sub>/F<sub>EO</sub>= 36/64to 45/55 mol/mol) were synthesized by using different monomer feed ratio. The melt-ing point （T<sub>m</sub>）, glass transition temperature （T<sub>g</sub>） and enthalpy of fusion （ΔH<sub>f</sub>） of thesecopolymers are depended on the copolymer composition and in the range of 87～102℃,-12～-18℃, and 37～66J/g, respectively. The second heating scan of DSC also in-dicated that the higher alternating copolymer was more easily recrystallized. The onsetdecomposition temperature was more than 300℃ under nitrogen and influenced by thecopolymer composition.
基金National Basic Research Program of China(No.2005CB623804)the National Natural Science Foundation of China(No.20476090).
文摘i-PP/m-EPR reactor alloy were prepared through ethylene/propylene slurry copolymerization catalyzed by metallocene(rac-Et(Ind)_2ZrCl_2)supported on porous iPP particles.Polar monomer(dihydromyrcene alcohol)treated with triethyaluminum was added in the preparation of porous iPP particles to introduce hydroxyl groups and thus enhance the ability for chemically supporting the metallocene catalyst.The effects of MAO/Zr ratio and monomer composition in feed on the reaction activity and property of polymer wer...
基金the National Natural Science Foundation of China (No.50673071).
文摘2,2,3,3,4,4,5,5-Octafluoropentyl acrylate was grafted onto silk fiber in a two-step heterogeneous system through the vinyl bonds of acryloyloxyethyl isocyanate modified on the silk.The grafted copolylner was analyzed by FTIR and WAXD,and the results revealed that the fluoroacrylate was successfully grafted onto silk fiber and the crystalline structure of silk fibroin withβ-sheet structure was not changed after graft copolymerization.The FT-IR corrected method was used to simulate the grafting yield onto ...
文摘Lignin isolated from enzymatic hydrolyzed corn-stalks (EH-lignin) is a renewable natural polymer noted for its versatility and applicability in a vari-ety of uses. Graft copolymerization of EH-lignin with acrylamide (AM) and the application of this copolymer as a flocculant in dye wastewater treatment were studied in this article. The influ-ences of some factors on yield of copolymer and the grafting ratio were investigated and the structure of EH-lignin/AM graft copolymer was characterized by FT-IR. According to the yield and the grafting ratio, the optimum conditions for graft copolymerization were as follows: initiator K2S2O8-Na2S2O3 with a quantity 3 wt% of EH-lignin, mass ratio of AM to EH-lignin was 2~3, reaction time 4h and temperature at 50℃. It was found that the absorption capacity of graft copolymer to two azo-dyes was enhanced with the increase of grafting ratio. Furthermore, the residue concen-tration of EH-lignin/AM graft copolymer remained in the supernatant after flocculation was much lower than that of pure EH-lignin.
基金supported by The National Natural Science Foundation of China(21504039)。
文摘Recyclable polymers offer a great opportunity to address the environmental issues of plastics.Herein,functionalization of recyclable polymers,poly((R)-3,4-trans six-membered ring-fused GBL)(P((R)-M)),were reported via end-group modifications and block/random copolymerizations.Di-n-butylmagnesium was selected to catalyze ring-opening polymerization(ROP)of(R)-M in the presence of a series of functional alcohols as the initiators.Block/random copolymerizations of(R)-M andε-caprolactone(ε-CL),L-lactide(L-LA)and trimethylene carbonate(TMC)were performed to control the onset decomposition temperature(T_(d)),melting temperature(T_(m))and glass transition temperature(T_(g)).These functionalized recyclable polymers would find broad applications as the sustainable plastics.
基金Project (Nos. 29734144 and 20274037) supported by the National Natural Science Foundation of China
文摘Ethylene/1-hexene was copolymerized by an unbridged zirconocene, (2-PhInd)2ZrCl2/MAO (methyl aluminoxane) at 0 °C and 50 °C respectively. High copolymerization activity and 1-hexene incorporation were observed at 0 °C, with the co- polymer formed having random sequence distribution and narrow molecular weight distribution. Ethylene polymerization at 50 °C showed high activity, but copolymerization at 50 °C showed much lower activity, which decreased sharply with increasing 1-hexene concentration in the monomer feed. Copolymer formed at 50 °C showed blocky sequence distribution and broad mo- lecular weight distribution. A mechanism model based on ligand rotation hindered by the propagation chain has been proposed to qualitatively explain the observed phenomena.
文摘（CpCH<sub>2</sub>CH<sub>2</sub>CH = CH<sub>2</sub>）<sub>2</sub>MCl<sub>2</sub>（M=Zr, Hf）/MAO and Cp<sub>2</sub>ZrCl<sub>2</sub>/MAO （Cp=cyclopentadienyl; MAO=methylaluminoxane） catalyst systems have been compared for ethylene copolymerization to investigate the influence of theligand and transition metal on the polymerization activity and copolymer properties. For both CH<sub>2</sub>CH<sub>2</sub>CH=CH<sub>2</sub> substitutedcatalysts the catalytic activity decreased with increasing propene concentration in the feed. The activity of the hafnocenecatalyst was 6～8 times lower than that of the analogous zirconocene catalyst, <sup>13</sup>C NMR analysis showed that the copolymerobtained using the unsubstituted catalyst Cp<sub>2</sub>ZrCl<sub>2</sub> has greater incorporatien of propene than those produced byCH<sub>2</sub>CH<sub>2</sub>CH=CH<sub>2</sub> substituted Zr and Hf catalysts. The melting point, crystallinity and the viscosity-average molecularweight of the copolymer decreased with an increase of propenc concentration in the feed. Both CH<sub>2</sub>CH<sub>2</sub>CH= CH<sub>2</sub> substitutedZr and Hf catalysts exhibit little or no difference in the melting point and crystallinity of the produced copolymers. However,there are significant differences between the two zirconocene catalysts. The copolymer produced by Cp<sub>2</sub>ZrCl<sub>2</sub> catalyst havemuch lower T<sub>m</sub> and X<sub>c</sub> than those obtained with the （CpCH<sub>2</sub>CH<sub>2</sub>CH=CH<sub>2</sub>）<sub>2</sub>ZrCl<sub>2</sub> catalyst. The density and molecular weightof the copolymer decreased in the order: （CpCH<sub>2</sub>CH<sub>2</sub>CH=CH<sub>2</sub>）<sub>2</sub>HfCl<sub>2</sub>】（CpCH<sub>2</sub>CH<sub>2</sub>CH=CH<sub>2</sub>）<sub>2</sub>ZrCl<sub>2</sub>】Cp<sub>2</sub>ZrCl<sub>2</sub>. The kineticbehavior of copolymerizaton with Hf catalyst was found to be different from that with Zr catalyst.
基金This work was financially supported by the Natural Science Foundation of China(Nos.50663001,20564001)Ministry of Education(No.2007-207058).
文摘The copolymerization of dibenzofuran(DBF)and 3-methylthiophene(MET)was successfully achieved electrochemically by direct anodic oxidation of the monomer mixtures in boron trifluoride diethyl etherate.The effects of applied polymerization potential and the monomer concentration ratios on the copolymerization were investigated by linear sweep voltammetry and cyclic voltammetry(CV).The structure of copolymer films were investigated by UV-Vis,infrared spectroscopy,thermal analysis.As-formed novel copolymers ...
文摘In homogeneous media, N,N-Dimethylacrylamide (DMA) was grafted copolymerization to cellulose by a metal-catalyzed atom transfer radical polymerization (ATRP) process. First, cellulose was dissolved in DMAc/LiCl system, and it reacted with 2-bromoisobutyloyl bromide (BiBBr) to produce macroinitiator (cell-BiB). Then DMA was polymerized to the cellulose backbone in a homogeneous DMSO solution in presence of the cell-BiB. Characterization with FT-IR, NMR, and GPC measurements showed that there obtained a graft copolymer with cellulose backbone and PDMA side chains (cell-PDMA) in well-defined structure. The proteins adsorption studies showed that the cellulose membranes modified by the as-prepared cell-PDMA copolymer owns good protein adsorption resistancet.
基金the Priority Academic Development Program for Textile Science and Textile Engineering of Jiangsu Higher Education Institutions,Chinathe Environmental Protection Department of Jiangsu Province,China(No.2012009)Suzhou Municipal Government,China(No.SYG201202)
文摘The monomer methacrylamido propyl trimethy ammonium chloride( MAPTAC) was copolymerized onto the fiber surface of polypropylene( PP) nonwoven fabric under ultroviole radiation. The weak acid red GN dye adsorption and adsorptive filtration performance of the resulted PP fabrics were investigated.The results showed that the grafting copolymerization preferred to happen in the inner layer of the fabrics. The water flux of the grafted fabrics decreases with the increase of grafting yield. The collapse of the grafted polymer chains causes the flux increase in acidic condition,or vice versa at alkaline version. The coiling of the polyelectrolyte chains upon the dye adsorption seems to violate the routine assumption of the rigid substrate, and this gets the adsorption energy constant negative. The static adsorption process follows the Lagergren's pseudo-second order kinetic equation. The removals of circa( ca.) 100% of the total permeation volume3 500 mL simulated dye wastewater was reached during permeation.The dye adsorbed fabrics were regenerated by the mixed media of the cationic surfactant / ethanol /water. The grafted fabric assumes stable fabric integrity and stability during permeation,and presents excellent dye adsorption capacity,easy desorption, and repeatable utilization.
文摘Radical copolymerization of N-phenylmaleedde with cyclohexene was carried out with 2, 2’ -azobisisobutyronitrile in various solvents at 60℃. The copolymer was characterized by IR and
基金This work was supported by the National Natural Science Foundation of China (No. 20074027), the State Key Laboratory of Physical Chemistry of the Solid Surface at Xiamen University and the Laboratory of Organic Solids, Institute of Chemistry, Chinese Aca
文摘The electrochemical copolymerization of aniline and N,N,N'-trimethylthionin (azure B) in aqueous solutions has been carried out using the potential sweep method. The optimum conditions for the coelectrodeposition are that the pH value and the temperature of the electrolytic solution are controlled at 5.57 and 30℃, respectively, and the scan potential range is set between -0.25 and 1.10 V (versus SCE). The copolymerization rate of aniline and azure B is about 3 times larger than that of aniline in the absence of azure B. The copolymerization of aniline and azure B was verified from the results of visible spectra during electrolysis, FTIR spectra and the atomic force microscopy (AFM) images of the polymers. The in situ visible spectrum for the electrolysis of the solution containing aniline and azure B is different from that of the respective aniline and azure B. The FTIR spectrum of the copolymer is not a superposition of that of polyaniline and poly(azure B). The AFM image of the copolymer is different from those of polyaniline and poly(azure B) and is not a mixture of individual polymers. The conductivity of the copolymer synthesized at pH 5.57 is four orders of magnitude higher than that of polyaniline synthesized under the same conditions, but in the absence of azure B. The electrochemical properties of the copolymer are mainly attributed to polyaniline, but the copolymer has a better electrochemical reversibility and a much faster charge transfer than those of polyaniline.
文摘The copolymerization of 2-hydroxyethyl acrylate （HEA, M<sub>1</sub>） and methylmethacrylate （MMA, M<sub>2</sub>） in cyclohexanone was studied. The multiple experiments ofsolution copolymerization with low conversion were carried out at two sensitive compositionfeed points at 60, 80, 100, 120 and 140℃, respectively. The composition of the copolymerswas analyzed by <sup>1</sup>H-NMR. The reactivity ratios which were estimated by the Error-in-Variable Method （EVM） of Mayo-Lewis equation were found to be r<sub>1</sub> = 0.328, r<sub>2</sub> = 1.781for 60℃; 0.375, 1.709 for 80℃; 0.406, 1.654 for 100℃; 0.439, 1.540 for 120℃ and 0.455,1.400 for 140℃, and the 95% joint confidence intervals of the reactivity ratios were alsodetermined. According to r<sub>1</sub> and r<sub>2</sub>, Arrhenius relations and the activity energy differencebetween the homo- and cross-propagation were calculated.
