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SURFACE MODIFICATION OF MICROPOROUS POLYPROPYLENE MEMBRANES BY graft polymerization OF N,N-DIMETHYLAMINOETHYL METHACRYLATE

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Chinese Journal of Polymer Science 2004年第4期22卷 369-377页

作者：徐志康 Patrick Seta Institute of Polymer Science Zhejiang University Hangzhou 310027 China LMPM UMR 5635 CNRS 34293 Montpellier Cedex 05 France

Surface modification of microporous polypropylene hollow fiber membranes was performed by radical-induced graft polymerization of N,N-dimethylaminoethyl methacrylate (DMAEMA). The influences of temperature, monomer concentration and pre-adsorbed amount of benzoyl peroxide on grafting degree were studied respectively. It was found that the appropriate graft temperature was 75 'C, at which the grafting degree was the highest and the hydrolytic decomposition of DMAEMA the lowest. Scanning electron photomicrography and the average pore diameters of the modified membranes demonstrated that part of the micropores on the membrane surface was plugged by the grafted polyDMAEMA chains, especially at high grafting degree. Contact angle and water swelling experiments showed that a moderate grafting degree could improve the hydrophilicity of the membranes. In the range of 11.3%-12.0% grafting degree, the water swelling percentage reached its maximum (51.1%) and the contact angle reached its minimum (74 degrees). The bovine serum albumin (BSA) adsorption experiment indicated that the grafted polyDMAEMA had a dual effect on protein adsorption. At the first stage, the BSA adsorption decreased with increasing of DMAEMA grafting degree. As the interaction between BSA and polyDMAEMA on membrane surface increased, the BSA adsorption increased with increasing of DMAEMA grafting degree.

关键词： Polypropylene hollow fiber membrane N,N-Dimethylaminiethyl methacrylate Surface modification graft polymerization BSA adsorption

PHOTO-INDUCED graft polymerization OF ACRYLAMIDE ON POLYPROPYLENE MEMBRANE SURFACE IN THE PRESENCE OF DIBENZYL TRITHIOCARBONATE

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Chinese Journal of Polymer Science 2007年第2期25卷 221-226页

作者： Qian Yang Jing Tian Zhi-kang Xu Institute of Polymer Science and Key Laboratory of Macromolecule Synthesis and Functionalization （Ministry of Education） Zhejiang University Hangzhou 310027 China

Ultraviolet （UV）-induced graft polymerization of acrylamide （AAm） on polypropylene substrates was successfully conducted using dibenzyl trithiocarbonate （DBTTC） as photoinitiator. It was confirmed by chemical analysis and surface morphology observation with attenuated total reflectance Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. A possible mechanism for this graft process was presented, which suggested that, under UV irradiation, the C： S bond in DBTTC could split and abstract a hydrogen from the polypropylene surface and a surface free radical was then formed, and initiated the graft polymerization of AAm.

关键词： graft polymerization Surface modification Acrylamide Trithiocarbonate UV.

UV-induced Self-initiated graft polymerization of Acrylamide onto Poly(ether ether ketone)

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Chemical Research in Chinese Universities 2012年第1期28卷 162-165页

作者： CHEN Rui-chao, SUN Hui, LI Ang and XU Guo-zhi College of Materials Science and Mechanical Engineering, National Center for Quality Supervision and Test of Plastic Products, Beijing Technology and Business University, Beijing 100048, P. R. China College of Materials Science and Mechanical Engineering National Center for Quality Supervision and Test of Plastic Products Beijing Technology and Business University Beijing 100048

Photo-grafting of hydrophilic monomer was used to enhance the hydrophilicity of poly（ether ether ketone）（PEEK） with the aim of extending its applications to biological fields. PEEK sheets were surface modified by grafting of acrylamide（AAm） with ultraviolet（UV） irradiation in the presence or absence of benzophenone（BP）. The effects of BP, irradiation time and monomer concentration on the surface wettability of PEEK were investigated. Characteriza tion of modified PEEK using scanning electron microscopy（SEM）, energy-disperse spectrometer（EDS） and water contact angle measurements shows that AAm was successfully grafted on PEEK surface both in presence and absence of BP. With the increase in irradiation time and monomer concentration, contact angles decrease to as low as 30°, demonstrating a significant improvement of surface hydrophilicity. In agreement with the decrease in contact angle, under identical conditions, the nitrogen concentration increases, suggesting the increase in grafting degree of the grafting polymerization. This investigation demonstrates a self-initiation of PEEK due to its BP-like structure in the backbone of the polymer. Though the graft polymerization proceeds more readily in the presence of BP, the self-initiated graft polymerization is clearly observed.

关键词： Poly（ether ether ketone）（PEEK） UV-grafting Surface modification Self-initiation graft polymerization

Emulsion graft polymerization of Methyl Methacrylate onto Cellulose Nanofibers

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Green and Sustainable Chemistry 2021年第1期11卷 9-22页

作者： Hiromu Okada Chao Zhao Yusuke Mizuta Katsumi Yoshino Ryuichi Sugimoto School of Environmental Science and Engineering Kochi University of Technology Kochi Japan Shimane Institute for Industrial Technology Matsue Japan

Methyl methacrylate (MMA) was successfully grafted onto cellulose nanofibers (CNFs) at room temperature in an emulsion system using a diethyl(1,10-phenanthroline N1,N10)zinc(II) complex (Phen-DEZ) with oxygen as the radical initiator. The effects of reaction temperature, initiator concentration, and monomer content on the grafting reaction were investigated. The molecular weight of the non-grafted PMMA, which was produced during graft polymerization, was more than 1 million, as determined by size exclusion chromatography. The PMMA-grafted CNFs were analyzed by Fourier transform infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy, which confirmed the grafting of PMMA on the nanofiber surface. The study presents a strategy for the grafting of high-molecular weight PMMA onto CNFs in an emulsion system using Phen-DEZ and O2.

关键词： Cellulose Nanofibers graft polymerization Methyl Methacrylate Emulsion Diethylzinc

Anti-fouling ultrafiltration membrane prepared from polysulfone-graft-methyl acrylate copolymers by UV-induced grafting method

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Journal of Environmental Sciences 2008年第5期20卷 565-570页

作者： HUA Helin LI Na WU Linlin ZHONG Hui WU Guangxia YUAN Zonghuan LIN Xiangwei TANG Lianyi Research Center for Eco-Environmental Science Chinese Academy of Sciences Beijing 100085 China Department of Environment and Chemistry Engineering Nanchang Hangkong University Nanchang 330034 China The Greatwall Pharmaceutical Factory of Beijing Beijing 100071 China

Membrane fouling is one of the most important challenges faced in membrane ultrafiltration operations. The copolymers of polysulfone-graft-methyl acrylate were synthesized by homogeneous photo-initiated graft copolymerization. The variables affecting the degree of grafting, such as the time of UV （Ultraviolet-visible） irradiation and the concentrations of the methyl acrylate and photoinitiator, were investigated. The graft copolymer membranes were prepared by the phase inversion method. The chemical and morphological changes were characterized by attenuated total reflection-Fourier transform infrared spectroscopy （ATR/FT-IR）, scanning electron microscopy, and water contact angles measurements. Results revealed that methyl acrylate groups were present on the membranes and the graft degree of methyl acrylate had remarkable effect on the performance of membranes. Pure water contact angle on the membrane surface decreases with the increase of methyl acrylate graft degree, which indicated that the hydrophilicity of graft copolymer membranes was improved. The permeation fluxes of pure water and bovine serum albumin solution were measured to evaluate the antifouling property of graft copolymer membranes, the results of which have shown an enhancement of antifouling property for graft copolymer membranes.

关键词： polysulfone methyl acrylate UV irradiation graft polymerization

SURFACE MODIFICATION OF POLYPROPYLENE MICROPOROUS MEMBRANE BY TETHERING POLYPEPTIDES

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Chinese Journal of Polymer Science 2006年第5期24卷 529-538页

作者：徐志康 Mathias Ulbricht Institute of Polymer Science Department of Polymer Science & Engineering Zhejiang University Hangzhou 310027 China Institut für Technische Chemie Universit t Duisburg-Essen45117 EssenGermany

Two kinds of polypeptides were tethered onto the surface of polypropylene microporous membrane （PPMM） through a ring opening polymerization of L-glutamate N-carboxyanhydride initiated by amino groups which were introduced by ammonia plasma and y-aminopropyl triethanoxysilane treatments. X-ray photoelectron spectroscopy （XPS）, attenuated total reflectance Fourier transform infrared spectroscopy （FT-IR/ATR）, scanning electron microscopy （SEM）, together with water contact angle measurements were used to characterize the modified membranes. XPS analyses and FT-IR/ATR spectra demonstrated that polypeptides are actually grafted onto the membrane surface. The wettability of the membrane surface increases at first and then decreases with the increase in grafting degrees of polypeptide. Platelet adhesion and murine macrophage attachment experiments reveal an enhanced hemocompatibility for the polypeptide modified PPMMs. All these results give evidence that polypeptide grafting can simultaneously improve the hemocompatibility as well as reserve the hydrophobicity for the membrane, which will provide a potential approach to improve the performance of polypropylene hollow fiber microporous membrane used in artificial oxygenator.

关键词： Polypropylene microporous membrane graft polymerization Polypeptide Surface modification Biocompatibility.

ENHANCING HYDROPHILICITY AND PROTEIN RESISTANCE OF SILICONE HYDROGELS BY PLASMA INDUCED graftING WITH HYDROPHILIC POLYMERS

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Chinese Journal of Polymer Science 2010年第4期28卷 547-554页

作者：李新松 Biomaterials and Drug Delivery Laboratories School of Chemistry and Chemical EngineeringSoutheast University

The hydrophilicity of silicone hydrogels used as soft corneal contact lens plays an important role in wearing comfort. In order to enhance hydrophilicity and protein resistance, silicone hydrogel membranes were modified by atmospheric pressure glow discharge plasma （APGDP） induced surface graft polymerization of N-vinyl pyrrolidone （NVP） and poly（oligoethylene glycol methyl ether methacrylate）（PEGMA） in this paper. XPS analysis demonstrated the success of graft polymerization of NVP and PEGMA onto the surface of silicone hydrogel membranes. The hydrophilicity of silicone hydrogels was characterized by the measurement of water contact angle （WCA）. The result showed that NVP grafted silicone hydrogel has the WCA of about 68° and PEGMA grafted silicone hydrogel has the lowest WCA of about 62°, while the pristine silicone hydrogel is hydrophobic with the WCA of about 103°. Protein resistance of silicone hydrogels was investigated by the method of bicinchoninic acid assay using bovine serum albumin （BSA） as a model. It＇s found that the grafted silicone hydrogel has a significant improvement of protein resistance, and PEGMA grafting is more efficient for the reduction of protein adsorption than NVP grafting. The silicone hydrogel membranes grafted with NVP and PEGMA are good candidates of soft corneal contact lenses.

关键词： Silicone hydrogel APGDP graft polymerization Hydrophilicity

Surface Modification of SiC Nanoparticles with PMMA by Low Temperature Plasma

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Plasma Science and Technology 2007年第1期9卷 57-61页

作者：韦刚钟少锋孟月东舒兴胜 Institute of Plasma Physics Chinese Academy of SciencesHefei 230031China Institute of Plasma Physics Chinese Academy of SciencesHefei 230031China Academy of Opto-ElectronicsChinese Academy of SciencesBeijing 100010China

An investigation into Poly （methyl methacrylate）（PMMA） grafted onto nano-SiC particles is reported in this study. In our experiment, the grafting polymerization reaction is induced by radio frequency （RF） discharge of N2 plasma treatment of the nanosized powder. FTIR （Fourier transform infrared spectrum）, XPS （X-ray photoelectron spectroscopy） and TGA （Thermogravimetric analysis） results reveal that PMMA is grafted onto the surface of silicon carbide powder, and the crystal structure of the silicon carbide powder observed with XRD （X- ray diffraction） spectra is unchanged before and after the plasma graft polymerization.

关键词： plasma graft polymerization SiC nanoparticle PMMA

Plasma Induced grafting of PSt onto Titanium Dioxide Powder

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Plasma Science and Technology 2006年第3期8卷 321-324页

作者：钟少锋孟月东欧琼荣舒兴胜 Institute of Plasma Physics Chinese Academy of Sciences Hefei 230031 China College of Physical Science and Technology Central China Normal University Wuhan 430079 China Institute of Plasma Physics Chinese Academy of Sciences Hefei 230031 China

An investigation of grafting of polymer of styrene （PSt） onto titanium dioxide powder is reported in this paper. The graft polymerization reaction was induced by N2 plasma treatment on the surface of titanium dioxide. Infrared （IR） spectra and X-ray photospectrum （XPS） results showed that PSt was grafted onto the titanium dioxide powder. An observation by X-ray diffraction （XRD） spectra indicated that the crystal structure of the titanium dioxide powder was unchanged after the plasma treatment.

关键词： plasma titanium dioxide graft polymerization PSt