In this article, the synthesis and characterization of a novel fluoromonomer and its copolymer with acrylamide is reported. 2-perfluoroamyl-4-hydroxylquinoline 2 was synthesized from ethyl 2, 2-dihydroperfluoroheptano...In this article, the synthesis and characterization of a novel fluoromonomer and its copolymer with acrylamide is reported. 2-perfluoroamyl-4-hydroxylquinoline 2 was synthesized from ethyl 2, 2-dihydroperfluoroheptanoate in high yields. The monomer 4 was then synthesized from 2 in two steps readily in high yields. Synthesis and characterization of copolymers of acrylamide (AM) and the fluoromonomer were investigated. The composition and intrinsic viscosity of these copolymers were studied. It was found that the rheological properties of aqueous solutions of polyacrylamide were modified significantly when a small proportion of the fluoromonomer 4 was incorporated on investigating the viscosity-concentration profiles, pseudoplasticity of these solutions and the effect of the presence of surfactant. These results could be explained by the hydrophobic association of the fluorocarbon segments in the aqueous solutions of these copolymers.展开更多
In this paper, the mechanical behavior of acrylic polymers at elevated temperature was investigated. Four acrylic polymers were tested at high strain rate by using compression Hopkinson bar and at quasi-static strain ...In this paper, the mechanical behavior of acrylic polymers at elevated temperature was investigated. Four acrylic polymers were tested at high strain rate by using compression Hopkinson bar and at quasi-static strain rate by using an Instron servo hydraulic axial testing machine with the testing temperature from 218K to 393K. The results show that the mechanical property of acrylic polymers depends heavily on the testing temperature. The yield stress and Young's modulus were found to decrease with increasing temperature at low strain rate. At very low temperature, the materials display typical brittle fracture; however their plasticity improves remarkably at high temperatures. The predictions of the mechanical behavior including the effect of temperature and strain rate using a proposed theoretical model have a good agreement with experimental results.展开更多
The novel polymer metal chelate electrolytes(polychelates)were prepared by incorporation of cobalt sulfate(Co)into poly(acrylic acid)(PAA)host matrix.Quasi-solid state supercapacitor devices were fabricated using poly...The novel polymer metal chelate electrolytes(polychelates)were prepared by incorporation of cobalt sulfate(Co)into poly(acrylic acid)(PAA)host matrix.Quasi-solid state supercapacitor devices were fabricated using polychelates,PAA-Co X(X:3,5,7,and 10)where X represents the doping fraction(w/w)of Co in PAA.All polymer metal electrolytes were showed excellent bending-stretching properties,thermal stability and electrochemical durability with an optimum ionic conductivity of 3.15×10^(-4) S cm^(-1).Hierarchically porous activated carbon and nano-sized conductive carbon were used to form carbon composite symmetrical device electrodes.The electric double-layer capacitor(EDLC)and redox reactions of Co-incorporated polychelates at the interfaces of porous activated carbon provided an optimum specific capacitance of 341.33 F g^(-1) with a device of PAA-Co7,which is at least 15 times enhancement compared to the device of pristine PAA.The PAA-Co7 device also provided energy density of 21.25 Wh kg^(-1) at a power density of 117.69 W kg^(-1).A prolonged cyclic stability of the device exhibited superior capacitive performance after 10,000 charge-discharge cycles and the maintained 90%of its initial performance.In addition,the supercapacitor with a dimension of 1.5 cm×3 cm containing PAA-Co7 successfully operated the red-blue-green(RGB)LED light.展开更多
Solid polymer electrolytes (SPEs) of polyacrylamide-co-acrylic acid (PAA) as the polymer host and zinc acetate (ZnA) as an ionic dopant were prepared using a single solvent by the solution casting technique. The amorp...Solid polymer electrolytes (SPEs) of polyacrylamide-co-acrylic acid (PAA) as the polymer host and zinc acetate (ZnA) as an ionic dopant were prepared using a single solvent by the solution casting technique. The amorphous and crystalline structures of film were investigated by X-ray diffraction (XRD). The surface morphology of samples was examined by scanning electron microscopy (SEM). The composition and complex formation of films were characterized by Fourier transform infrared (FTIR) spectroscopy. The conductivity of the PAA-ZnA films was determined by electrochemical impedance spectroscopy. According to the XRD and FTIR analyses, all electrolyte films were in amorphous state and the existence of interaction between Zn2+ cations and the PAA structure confirms that the film was successfully prepared. The SEM observations reveal that the electrolyte films appeared to be rough and flat with irregularly shaped surfaces. The highest ionic conductivity (σ) of 1.82 × 10-5 Scm-1 was achieved at room temperature (303 K) for the sample containing 10 wt % ZnA.展开更多
A novel antibacterial acrylate polymer composite modified with capsaicin was successfully synthesized by a two-step reaction.Capsaicin and acryloyl chloride were firstly esterified,and then applied to solution polymer...A novel antibacterial acrylate polymer composite modified with capsaicin was successfully synthesized by a two-step reaction.Capsaicin and acryloyl chloride were firstly esterified,and then applied to solution polymerization with acrylate monomers and styrene.The yield of the esterified products was about 85.3%.The polymer was characterized by Fourier transform infrared spectroscopy(FTIR),gel permeation chromatography(GPC),thermogravimetric analysis(TGA),contact angle(CA)and antibacterial ring tests.The number-average molecular weight(M_n)of the polymer was 27214,based on the capsaicin-acrylate dosage of 6.5 wt%.The TGA revealed a stable thermal property.The contact angles of the polymers films on tinplate increased from 77.5°to 86.2°with the increasing amount of capsaicin-acrylate.The antibacterial tests demonstrated excellent antimicrobial capability of the polymers.展开更多
A Aeries of hydroxylic hyperbranched polymers were derived from 2,2-bis(methylol) propionic acid and tris(methylol) propane reacted with acrylic acid to various extents. The obtained acrylated hyperbranched polymers a...A Aeries of hydroxylic hyperbranched polymers were derived from 2,2-bis(methylol) propionic acid and tris(methylol) propane reacted with acrylic acid to various extents. The obtained acrylated hyperbranched polymers alone or with a monofunctional diluent, isobornylene acrylate(IBOA) were further cured by UV radiation. The cured films based on the modified polymers alone all demonstrated poor mechanical properties due to their high network densities and low moving ability of polymer chains. For the composite systems, the cured films demonstrated improved mechanical properties due to the low network densities and high chain moving ability. With more IBOA included in the systems, acrylate groups can react to a higher extent during the curing process.展开更多
A series of novel fluorine-containing acrylates 6a-6g were synthesized via the condensation of ethyl cyanoacetate and trifluoroacetic anhydride, followed by chloridization and the coupling reaction with amines. These ...A series of novel fluorine-containing acrylates 6a-6g were synthesized via the condensation of ethyl cyanoacetate and trifluoroacetic anhydride, followed by chloridization and the coupling reaction with amines. These new compounds exhibited some biological activity as preliminary bioassay indicated. A plausible reaction mechanism was outlined and discussed.展开更多
The increased demand of electronic devices promotes the development of advanced and more efficient energy storage devices, such as batteries. Lithium-ion batteries (LIBs) are the most studied battery systems due to th...The increased demand of electronic devices promotes the development of advanced and more efficient energy storage devices, such as batteries. Lithium-ion batteries (LIBs) are the most studied battery systems due to their high performance. Among the different battery components, the separator allows the control of lithium ion diffusion between the electrodes. To overcome some drawbacks of liquid electrolytes, including safety and environmental issues, solid polymer electrolytes (SPEs) are being developed. In this work, a UV photocurable polyurethane acrylate (PUA) resin has been blended with lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) up to 30 wt% LiTFSI content to reach a maximum ionic conductivity of 0.0032 mS/cm at room temperature and 0.09 mS/cm at 100 ℃. Those values allowed applying the developed materials as photocurable SPE in Swagelok type Li/C-LiFePO_(4) half-cells, reaching a battery discharge capacity value of 139 mAh.g^(−1) at C/30 rate. Those results, together with the theoretical studies of the discharge capacity at different C-rates and temperatures for batteries with LiTFSI/PUA SPE demonstrate the suitability of the developed photocurable SPE for LIB applications.展开更多
In this paper, the structure of 1-bromomethyl-7,7-dimethyl btcyclo[2.2.1]hept-2-yl acrylate has been studied by X-ray diffraction, and the relation between the molecular structure and the properties of polymerization ...In this paper, the structure of 1-bromomethyl-7,7-dimethyl btcyclo[2.2.1]hept-2-yl acrylate has been studied by X-ray diffraction, and the relation between the molecular structure and the properties of polymerization and its polymer have been discussed.展开更多
Molecularly imprinted polymers(MIPs) were applied as molecular recognition elements to an electro- chemical sensor for cinchonidine(CD). A kind of MIP was synthesized with cinchonidine as template, modified ro- si...Molecularly imprinted polymers(MIPs) were applied as molecular recognition elements to an electro- chemical sensor for cinchonidine(CD). A kind of MIP was synthesized with cinchonidine as template, modified ro- sin(ethylene glycol maleic rosinate acrylate) containing the skeleton of phenanthrene rings as cross-linker and me- thylacrylic acid as functional monomer. MIP membrane was prepared on a glassy carbon electrode for the determina- tion of CD via free radical polymerization method. Electrochemical impedance spectroscopy(EIS) and cyclic vol- tammetry(CV) were used to characterize the membrane electrochemical behavior in electrode fabrication process. The experimental conditions were discussed. Under optimum conditions, it was found that the response of peak cur- rents was linear to the concentration of CD in a range of 0.013-2.26 mmol/L. The detection limit for CD is 1 μmol/L the relative standard deviation for 100 μmol/L CD is 1.34% and the incubation time is 2 min. The sensor was applied to the determination of CD in urine samples with satisfactory results.展开更多
A novel bi-functional photorefractive acrylate polymer with pendant carbazolyl groups and azo derivatives as side chains was synthesized. Photorefractive experiments showed a high two-beam coupling gain coefficient of...A novel bi-functional photorefractive acrylate polymer with pendant carbazolyl groups and azo derivatives as side chains was synthesized. Photorefractive experiments showed a high two-beam coupling gain coefficient of 93 cm(-1), diffraction efficiency of 12% and electro-optic coefficient of 26 pm/V were obtained.展开更多
Novel interpenetrating polymer network (IPN) hydrogels based on konjac glucomannan (KGM) and poly(acrylic acid) (PAA) were prepared by polymerization and cross-linking of acrylic acid (AA) in the pre-fabrica...Novel interpenetrating polymer network (IPN) hydrogels based on konjac glucomannan (KGM) and poly(acrylic acid) (PAA) were prepared by polymerization and cross-linking of acrylic acid (AA) in the pre-fabricated KGM gel. The IPN gel was analyzed by FF-IR. The studies on the equilibrium swelling ratio of IPN hydrogels revealed their sensitive response to environmental pH value. The results of in vitro degradation showed that the IPN hydrogels retain the enzymatic degradation character of KGM.展开更多
Network polymer electrolytes with free oligo(oxyethylene) chains as internal plasticizers were prepared by cross-linking poly(ethylene glycol) acrylates. The effects of salt concentration and properties of internal pl...Network polymer electrolytes with free oligo(oxyethylene) chains as internal plasticizers were prepared by cross-linking poly(ethylene glycol) acrylates. The effects of salt concentration and properties of internal plasticizers on ionic conductivity were studied.展开更多
Poly(ether ether ketone)s(PEEK) are a class of high performance engineering thermoplastics known for their excellent thermal, mechanical, and electrical properties. This class of advanced materials has currently r...Poly(ether ether ketone)s(PEEK) are a class of high performance engineering thermoplastics known for their excellent thermal, mechanical, and electrical properties. This class of advanced materials has currently received considerable attention for potential application in aerospace, electronics, automobile and other high technology fields. However, it is difficult for PEEK to be processed because of their high melting temperature and poor solubility.展开更多
New liquid crystalline monomer,2,5-bis[(4'-methoxyphenoxy)carbonyl]phenyl acrylate was successfully synthesized.Polyacrylate with laterally attached mesogens via ei;ter linkage was also derived.This polymer forms ...New liquid crystalline monomer,2,5-bis[(4'-methoxyphenoxy)carbonyl]phenyl acrylate was successfully synthesized.Polyacrylate with laterally attached mesogens via ei;ter linkage was also derived.This polymer forms an enantiotropic liquid crystal phase while its monomer exhibits a metastable nematic phase with respect to the crystalline state.However,its liquid crystallinity is very low as compared to that of poly{2,5-bis[(4'-methoxyphenoxy)carbonyl]-styrene}.展开更多
Polymer nanoparticles were prepared in the methyl methacrylate (MMA)/buty lmethacrylate (BA) emulsion copolymerization process by a modified microemulsion copolymerization method. 2-Hydroxyethyl methacrylate(HEMA), ac...Polymer nanoparticles were prepared in the methyl methacrylate (MMA)/buty lmethacrylate (BA) emulsion copolymerization process by a modified microemulsion copolymerization method. 2-Hydroxyethyl methacrylate(HEMA), acrylate (AA) and methyl acrylate (MAA) were used as reactive cosurfactants. With this process high polymer: surfactant weight ratios (40:1 or greater),relatively concentrated (~30wt. %) latexes and small (~60nm) particle diameters were obtained.Properties of the latexes were characterized by TEM, DSC, dynamic light scattering, and IR spectroscopy.展开更多
Amphoteric polymer can be used as retanning agent in leather manufacture.It is particularly useful in chrome-free tanning systems since it can regulate the charge properties of chrome-free leather and enhance the fixa...Amphoteric polymer can be used as retanning agent in leather manufacture.It is particularly useful in chrome-free tanning systems since it can regulate the charge properties of chrome-free leather and enhance the fixation of anionic post-tanning chemicals in leather.However,the aggregation and precipitation of amphoteric polymer retanning agents around the isoelectric point(pl)hinder their wide application.Herein,we synthesized five amphoteric acrylic polymers(AAPs)by free radical copolymerization with acrylic acid and five different cationic acrylic monomers.The effect of cationic monomer structure on the aggregation behavior of AAPs was investigated.The aggregation of AAPs in aqueous solution showed pH and concentration dependence.Light scattering analysis showed that Poly(AAA-co-MAPTAC)and Poly(AA-co-DMAPMA)were in the shape of coiled linear flexible chains with small particle size(R_(g)7.6 nm and 14.8 nm,respectively)near the pl.However,Poly(AA-co-DAC),Poly(AA-co-DMC)and Poly(AA-co-DMAEMA)were in the shape of hollow spheres and exhibited serious aggregation.Quantum chemical calculations suggested that the amide groups in the cationic monomers MAPTAC and DMAPMA enhanced the nucleophilicity of AAPs.Thus the corresponding AAPs could carry a large number of cationic charges to slow their aggregation when the pH just climbed over the pl.The results are expected to provide theoretical reference for the synthesis and wide-spread application of AAPs.展开更多
Polyethylene terephthalate(PET)and polyethylene(PE)fibers were surface photo-grafted with acrylic acid(AA)by using UV irradiation photochemical initiationduring a continuous winding process within 1-2 min-utes.The gra...Polyethylene terephthalate(PET)and polyethylene(PE)fibers were surface photo-grafted with acrylic acid(AA)by using UV irradiation photochemical initiationduring a continuous winding process within 1-2 min-utes.The grafted fibers were characterized by measure-ments of dye uptaking,moisture regain,pull-out forcesof monofilament from cured matrix,as well as by analy-sis of ESCA and ATR-FTIR spectra.All these resultsconfirm that the surface behavior of the UV-irradiationgrafted fibers was greatly improved.It was also provedthat the original excellent mechanical properties of the fi-bers were well-retained after the surface grafting treat-ment.展开更多
基金Project supported by National Natural Science Foundation,Grant approval numbers 29472074 and 29632003
文摘In this article, the synthesis and characterization of a novel fluoromonomer and its copolymer with acrylamide is reported. 2-perfluoroamyl-4-hydroxylquinoline 2 was synthesized from ethyl 2, 2-dihydroperfluoroheptanoate in high yields. The monomer 4 was then synthesized from 2 in two steps readily in high yields. Synthesis and characterization of copolymers of acrylamide (AM) and the fluoromonomer were investigated. The composition and intrinsic viscosity of these copolymers were studied. It was found that the rheological properties of aqueous solutions of polyacrylamide were modified significantly when a small proportion of the fluoromonomer 4 was incorporated on investigating the viscosity-concentration profiles, pseudoplasticity of these solutions and the effect of the presence of surfactant. These results could be explained by the hydrophobic association of the fluorocarbon segments in the aqueous solutions of these copolymers.
文摘In this paper, the mechanical behavior of acrylic polymers at elevated temperature was investigated. Four acrylic polymers were tested at high strain rate by using compression Hopkinson bar and at quasi-static strain rate by using an Instron servo hydraulic axial testing machine with the testing temperature from 218K to 393K. The results show that the mechanical property of acrylic polymers depends heavily on the testing temperature. The yield stress and Young's modulus were found to decrease with increasing temperature at low strain rate. At very low temperature, the materials display typical brittle fracture; however their plasticity improves remarkably at high temperatures. The predictions of the mechanical behavior including the effect of temperature and strain rate using a proposed theoretical model have a good agreement with experimental results.
基金Deputyship for Research&Innovation,Ministry of Education in Saudi Arabia for funding this research work。
文摘The novel polymer metal chelate electrolytes(polychelates)were prepared by incorporation of cobalt sulfate(Co)into poly(acrylic acid)(PAA)host matrix.Quasi-solid state supercapacitor devices were fabricated using polychelates,PAA-Co X(X:3,5,7,and 10)where X represents the doping fraction(w/w)of Co in PAA.All polymer metal electrolytes were showed excellent bending-stretching properties,thermal stability and electrochemical durability with an optimum ionic conductivity of 3.15×10^(-4) S cm^(-1).Hierarchically porous activated carbon and nano-sized conductive carbon were used to form carbon composite symmetrical device electrodes.The electric double-layer capacitor(EDLC)and redox reactions of Co-incorporated polychelates at the interfaces of porous activated carbon provided an optimum specific capacitance of 341.33 F g^(-1) with a device of PAA-Co7,which is at least 15 times enhancement compared to the device of pristine PAA.The PAA-Co7 device also provided energy density of 21.25 Wh kg^(-1) at a power density of 117.69 W kg^(-1).A prolonged cyclic stability of the device exhibited superior capacitive performance after 10,000 charge-discharge cycles and the maintained 90%of its initial performance.In addition,the supercapacitor with a dimension of 1.5 cm×3 cm containing PAA-Co7 successfully operated the red-blue-green(RGB)LED light.
文摘Solid polymer electrolytes (SPEs) of polyacrylamide-co-acrylic acid (PAA) as the polymer host and zinc acetate (ZnA) as an ionic dopant were prepared using a single solvent by the solution casting technique. The amorphous and crystalline structures of film were investigated by X-ray diffraction (XRD). The surface morphology of samples was examined by scanning electron microscopy (SEM). The composition and complex formation of films were characterized by Fourier transform infrared (FTIR) spectroscopy. The conductivity of the PAA-ZnA films was determined by electrochemical impedance spectroscopy. According to the XRD and FTIR analyses, all electrolyte films were in amorphous state and the existence of interaction between Zn2+ cations and the PAA structure confirms that the film was successfully prepared. The SEM observations reveal that the electrolyte films appeared to be rough and flat with irregularly shaped surfaces. The highest ionic conductivity (σ) of 1.82 × 10-5 Scm-1 was achieved at room temperature (303 K) for the sample containing 10 wt % ZnA.
基金Supported by the State Key Laboratory of Advanced Power Transmission Technology(GEIRI-SKL-2018-005).
文摘A novel antibacterial acrylate polymer composite modified with capsaicin was successfully synthesized by a two-step reaction.Capsaicin and acryloyl chloride were firstly esterified,and then applied to solution polymerization with acrylate monomers and styrene.The yield of the esterified products was about 85.3%.The polymer was characterized by Fourier transform infrared spectroscopy(FTIR),gel permeation chromatography(GPC),thermogravimetric analysis(TGA),contact angle(CA)and antibacterial ring tests.The number-average molecular weight(M_n)of the polymer was 27214,based on the capsaicin-acrylate dosage of 6.5 wt%.The TGA revealed a stable thermal property.The contact angles of the polymers films on tinplate increased from 77.5°to 86.2°with the increasing amount of capsaicin-acrylate.The antibacterial tests demonstrated excellent antimicrobial capability of the polymers.
基金Supported by the National Natural Science Foundation of China(No.2 0 2 0 4 0 0 5 ,5 0 2 330 30 ) and Basic Research Fund ofTsinghua University(No.JC2 0 0 2 0 30 )
文摘A Aeries of hydroxylic hyperbranched polymers were derived from 2,2-bis(methylol) propionic acid and tris(methylol) propane reacted with acrylic acid to various extents. The obtained acrylated hyperbranched polymers alone or with a monofunctional diluent, isobornylene acrylate(IBOA) were further cured by UV radiation. The cured films based on the modified polymers alone all demonstrated poor mechanical properties due to their high network densities and low moving ability of polymer chains. For the composite systems, the cured films demonstrated improved mechanical properties due to the low network densities and high chain moving ability. With more IBOA included in the systems, acrylate groups can react to a higher extent during the curing process.
基金The project supported by the National Natural Science Foundation of China(No.2017203 1)the Chinese Research Fund for the Doctoral Pr ogram of High Education.
文摘A series of novel fluorine-containing acrylates 6a-6g were synthesized via the condensation of ethyl cyanoacetate and trifluoroacetic anhydride, followed by chloridization and the coupling reaction with amines. These new compounds exhibited some biological activity as preliminary bioassay indicated. A plausible reaction mechanism was outlined and discussed.
基金Work supported by the Portuguese national funds(PIDDAC),through the Portuguese Foundation for Science and Technology(FCT)and FCT/MCTES:projects UID/FIS/04650/2020.UID/QUI/0686/2020,UID/CTM/50025/2020,UIDB/05549/2020,PTDC/FIS-MAC/28157/2017Grants SFRH/BD/140842/2018(J.C.B.),CEECIND/00833/2017(R.G.)and SFRH/BPD/112547/2015(C.M.C.).Financial support from the Basque Government Industry Departments under the ELKARTEK and HAZITEK programs is also acknowledged.
文摘The increased demand of electronic devices promotes the development of advanced and more efficient energy storage devices, such as batteries. Lithium-ion batteries (LIBs) are the most studied battery systems due to their high performance. Among the different battery components, the separator allows the control of lithium ion diffusion between the electrodes. To overcome some drawbacks of liquid electrolytes, including safety and environmental issues, solid polymer electrolytes (SPEs) are being developed. In this work, a UV photocurable polyurethane acrylate (PUA) resin has been blended with lithium bis(trifluoromethanesulfonyl) imide (LiTFSI) up to 30 wt% LiTFSI content to reach a maximum ionic conductivity of 0.0032 mS/cm at room temperature and 0.09 mS/cm at 100 ℃. Those values allowed applying the developed materials as photocurable SPE in Swagelok type Li/C-LiFePO_(4) half-cells, reaching a battery discharge capacity value of 139 mAh.g^(−1) at C/30 rate. Those results, together with the theoretical studies of the discharge capacity at different C-rates and temperatures for batteries with LiTFSI/PUA SPE demonstrate the suitability of the developed photocurable SPE for LIB applications.
文摘In this paper, the structure of 1-bromomethyl-7,7-dimethyl btcyclo[2.2.1]hept-2-yl acrylate has been studied by X-ray diffraction, and the relation between the molecular structure and the properties of polymerization and its polymer have been discussed.
基金Supported by the National Nature Science Foundation of China(Nos.21065001 and 30960306)the Natural Science Foundation of Guangxi Province,China(Nos.0639025,0991084 and 0991001z)+2 种基金the Fund of Guangxi Key Laboratory of Chemistry and Engineering of Forest Products,China(No.GXFC08-06)the Project of Education Department of Guangxi Province,China(No.200812MS074)the Innovation Project of Guangxi University for Nationalities,China(No.gxun-chx2011086)
文摘Molecularly imprinted polymers(MIPs) were applied as molecular recognition elements to an electro- chemical sensor for cinchonidine(CD). A kind of MIP was synthesized with cinchonidine as template, modified ro- sin(ethylene glycol maleic rosinate acrylate) containing the skeleton of phenanthrene rings as cross-linker and me- thylacrylic acid as functional monomer. MIP membrane was prepared on a glassy carbon electrode for the determina- tion of CD via free radical polymerization method. Electrochemical impedance spectroscopy(EIS) and cyclic vol- tammetry(CV) were used to characterize the membrane electrochemical behavior in electrode fabrication process. The experimental conditions were discussed. Under optimum conditions, it was found that the response of peak cur- rents was linear to the concentration of CD in a range of 0.013-2.26 mmol/L. The detection limit for CD is 1 μmol/L the relative standard deviation for 100 μmol/L CD is 1.34% and the incubation time is 2 min. The sensor was applied to the determination of CD in urine samples with satisfactory results.
文摘A novel bi-functional photorefractive acrylate polymer with pendant carbazolyl groups and azo derivatives as side chains was synthesized. Photorefractive experiments showed a high two-beam coupling gain coefficient of 93 cm(-1), diffraction efficiency of 12% and electro-optic coefficient of 26 pm/V were obtained.
基金The authors are grateful for the financial support of the National Natural Science Foundation of China (No. 20174029)National Key Basic Research and Development Program (2005CB623903).
文摘Novel interpenetrating polymer network (IPN) hydrogels based on konjac glucomannan (KGM) and poly(acrylic acid) (PAA) were prepared by polymerization and cross-linking of acrylic acid (AA) in the pre-fabricated KGM gel. The IPN gel was analyzed by FF-IR. The studies on the equilibrium swelling ratio of IPN hydrogels revealed their sensitive response to environmental pH value. The results of in vitro degradation showed that the IPN hydrogels retain the enzymatic degradation character of KGM.
文摘Network polymer electrolytes with free oligo(oxyethylene) chains as internal plasticizers were prepared by cross-linking poly(ethylene glycol) acrylates. The effects of salt concentration and properties of internal plasticizers on ionic conductivity were studied.
基金Supported by the Natural Science Foundation of Beij ing City,China(No.2062021)
文摘Poly(ether ether ketone)s(PEEK) are a class of high performance engineering thermoplastics known for their excellent thermal, mechanical, and electrical properties. This class of advanced materials has currently received considerable attention for potential application in aerospace, electronics, automobile and other high technology fields. However, it is difficult for PEEK to be processed because of their high melting temperature and poor solubility.
基金This project was supported by China Postdoctoral Science Foundation and National Natural Science Foundation of China(No.59873001).
文摘New liquid crystalline monomer,2,5-bis[(4'-methoxyphenoxy)carbonyl]phenyl acrylate was successfully synthesized.Polyacrylate with laterally attached mesogens via ei;ter linkage was also derived.This polymer forms an enantiotropic liquid crystal phase while its monomer exhibits a metastable nematic phase with respect to the crystalline state.However,its liquid crystallinity is very low as compared to that of poly{2,5-bis[(4'-methoxyphenoxy)carbonyl]-styrene}.
基金CEM Foundation For N & T Joint Academy (Chinese Education Ministry Foundation for Nankai University and Tianjin University Joint Academy)
文摘Polymer nanoparticles were prepared in the methyl methacrylate (MMA)/buty lmethacrylate (BA) emulsion copolymerization process by a modified microemulsion copolymerization method. 2-Hydroxyethyl methacrylate(HEMA), acrylate (AA) and methyl acrylate (MAA) were used as reactive cosurfactants. With this process high polymer: surfactant weight ratios (40:1 or greater),relatively concentrated (~30wt. %) latexes and small (~60nm) particle diameters were obtained.Properties of the latexes were characterized by TEM, DSC, dynamic light scattering, and IR spectroscopy.
基金supported by the Tianfu Ten-thousand Talents Program of Sichuan Province and the National Key R&D Program(2017YFB0308500).
文摘Amphoteric polymer can be used as retanning agent in leather manufacture.It is particularly useful in chrome-free tanning systems since it can regulate the charge properties of chrome-free leather and enhance the fixation of anionic post-tanning chemicals in leather.However,the aggregation and precipitation of amphoteric polymer retanning agents around the isoelectric point(pl)hinder their wide application.Herein,we synthesized five amphoteric acrylic polymers(AAPs)by free radical copolymerization with acrylic acid and five different cationic acrylic monomers.The effect of cationic monomer structure on the aggregation behavior of AAPs was investigated.The aggregation of AAPs in aqueous solution showed pH and concentration dependence.Light scattering analysis showed that Poly(AAA-co-MAPTAC)and Poly(AA-co-DMAPMA)were in the shape of coiled linear flexible chains with small particle size(R_(g)7.6 nm and 14.8 nm,respectively)near the pl.However,Poly(AA-co-DAC),Poly(AA-co-DMC)and Poly(AA-co-DMAEMA)were in the shape of hollow spheres and exhibited serious aggregation.Quantum chemical calculations suggested that the amide groups in the cationic monomers MAPTAC and DMAPMA enhanced the nucleophilicity of AAPs.Thus the corresponding AAPs could carry a large number of cationic charges to slow their aggregation when the pH just climbed over the pl.The results are expected to provide theoretical reference for the synthesis and wide-spread application of AAPs.
文摘Polyethylene terephthalate(PET)and polyethylene(PE)fibers were surface photo-grafted with acrylic acid(AA)by using UV irradiation photochemical initiationduring a continuous winding process within 1-2 min-utes.The grafted fibers were characterized by measure-ments of dye uptaking,moisture regain,pull-out forcesof monofilament from cured matrix,as well as by analy-sis of ESCA and ATR-FTIR spectra.All these resultsconfirm that the surface behavior of the UV-irradiationgrafted fibers was greatly improved.It was also provedthat the original excellent mechanical properties of the fi-bers were well-retained after the surface grafting treat-ment.