Preparation and Characterization of PMMA-b-PDMAEMA/Polysulfone Composite Membranes by RAFT Polymerization and their Permeation Performance of Carbon Dioxide

2011 ◽  
Vol 284-286 ◽  
pp. 1717-1723 ◽  
Author(s):  
Jiang Nan Shen ◽  
Yun Fei Ye ◽  
Gan Ning Zeng ◽  
Jun Hong Qiu
Keyword(s):  
Chain Transfer ◽  
Raft Polymerization ◽  
Gel Permeation Chromatography ◽  
Composite Membranes ◽  
Reversible Addition ◽  
Composition And Structure ◽  
Gel Permeation ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

PMMA-b-PDMAEMA/polysulfone composite membranes for CO2separation was prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization techniques. The chemical composition and structure of the polymers were characterized by Fourier transform infrared (FT-IR) spectroscopy, nuclear magnetic resonance (NMR), and molecular weight and its distribution were measured by Gel permeation chromatography (GPC). CO2permeation performance of the PMMA-b-PDMAEMA/ polysulfone composite membranes was test. The results showed that the resulted composited membrane posses good permeation performance for CO2.

scholarly journals Preparation and characterization of polyacrylate functionalized polythiophene films

2018 ◽  
Vol 175 ◽  
pp. 01007
Author(s):  
Yahui Lv ◽  
Fei Wu ◽  
Chengshuai Liu ◽  
Changzhong Liao ◽  
Yingheng Fei ◽  
...  
Keyword(s):  
Chain Transfer ◽  
Electrochemical Sensors ◽  
Raft Polymerization ◽  
Free Standing ◽  
Fluorescence Spectrophotometry ◽  
Electrochemical Reversibility ◽  
Reversible Addition ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

This paper is based on the effect of precursors’ structure on the resultant electropolymers’ electrochemical and optical and thermal properties. The polyacrylate functionalized thiophene with a narrow polydispersity index (PDI) was synthesized by means of reversible addition-fragmentation chain transfer (RAFT) polymerization, and then the free-standing and conducting conjugated polyacrylate functionalized polythiophene (R-PTE-PAA) film was prepared through electropolymerization in CH2Cl2 with 50% BFEE (boron trifluoride diethyl etherate). For comparison, the polyacrylate functionalized polythiophene (PTE-PAA) was also prepared with the precursor of a broad PDI from conventional free radical polymerization. The prepared polymers were characterized by UV-vis, FT-IR spectroscopy, thermogravimetry, cyclic voltammetry, scanning electron microscopy and fluorescence spectrophotometry. The R-PTE-PAA film showed the excellent electrochemical behavior, good blue-light property and high thermal stability. Compared with PTE-PAA, the R-PTE-PAA film presented the better electrochemical reversibility and stability. The results obtained in the present study indicate that the R-PTE-PAA film would be important for applications in electrochromics, supercapacitors and electrochemical sensors.

Chiral Recognition of L-Carnitine Using Surface Molecularly Imprinted Microspheres via RAFT Polymerization

2014 ◽  
Vol 884-885 ◽  
pp. 33-36 ◽  
Author(s):  
Lin Tong Hou ◽  
Jiao Jiao Chen ◽  
Hong Jun Fu ◽  
Xin Lei Fu
Keyword(s):  
Experimental Data ◽  
Chiral Recognition ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
Isothermal Adsorption ◽  
Molecularly Imprinted ◽  
Reversible Addition ◽  
Ft Ir ◽  
Molecularly Imprinted Microspheres

A molecularly imprinted microsphere (MIPs) was prepared successfullyviasurface-initiated reversible addition-fragmentation chain transfer (RAFT) polymerization. Characterization of the obtained MIPs was achieved by FT-IR and TGA. The isothermal adsorption and chiral separation experiments of MIPs on L-Carnitine were investigated. Compared with non-imprinted microsphere (NMIPs) adsorbent, MIPs showed faster adsorption rate and stronger adsorption capacity for L-Carnitine. Equilibrium experimental data of MIPs fitted the Langmuir isotherm better. Furthermore, the MIPs also exhibited enantioselectivity for L-Carnitine through the resolution experiment.

scholarly journals Structural and Thermal Characterization of Novel Organosolv Lignins from Wood and Herbaceous Sources

Processes ◽  
2020 ◽  
Vol 8 (7) ◽  
pp. 860 ◽  
Author(s):  
Anna Trubetskaya ◽  
Heiko Lange ◽  
Bernd Wittgens ◽  
Anders Brunsvik ◽  
Claudia Crestini ◽  
...  
Keyword(s):  
Thermogravimetric Analysis ◽  
Gel Permeation Chromatography ◽  
Thermal Characterization ◽  
Structural Features ◽  
Isolation Method ◽  
Structural Variations ◽  
Gel Permeation ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

This study demonstrates the effects of structural variations of lignins isolated via an organosolv process from different woody and herbaceous feedstocks on their thermal stability profiles. The organosolv lignins were first analysed for impurities, and structural features were determined using the default set of gel permeation chromatography, FT-IR spectroscopy, quantitative 31 P NMR spectroscopy and semi-quantitative 1 H- 13 C HSQC analysis. Pyrolysis-, O 2 - and CO 2 -reactivity of the organosolv lignins were investigated by thermogravimetric analysis (TGA), and volatile formation in various heating cycles was mapped by head-space GC-MS analysis. Revealed reactivities were correlated to the presence of identified impurities and structural features typical for the organosolv lignins. Data suggest that thermogravimetric analysis can eventually be used to delineate a lignin character when basic information regarding its isolation method is available.

scholarly journals Ulvan as A New Trend in Agriculture, Food Processing and Medicine

2020 ◽  
pp. 47-54
Author(s):  
Hadear Hanie Amin
Keyword(s):  
Food Processing ◽  
Gel Permeation Chromatography ◽  
Sulfated Polysaccharide ◽  
Hot Water ◽  
Human Pathogen ◽  
Hot Water Extraction ◽  
Gel Permeation ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

In this work the researcher is looking for natural, new, safe, cheap and available compounds that can be used as antimicrobial and antioxidant in the medical and agricultural fields. A sulfated polysaccharide, Ulvan was extracted from Ulva lactuca and purified by cold or hot water-extraction and ethanol-precipitation with yield = 5:10% (w-w). Its appearance and touch like gel. Characterization of active groups of Ulvan was achieved by FT-IR spectroscopy, its content of sulfate = 3.998% (w-w) was determined by Ion Chromatography (IC), its molecular weight = 532.221 Kilo Daltons was determined by Gel permeation chromatography, its thermal stability was evaluated by DSC-TGA, its viscosity = 18 was determined by viscometer apparatus and its antimicrobial activity was studied against human, plant, animal, fish and poultry pathogens. Ulvan showed antioxidant activity with IC50 = 3.04 mg/ml. Its biological activity as an antioxidant and antimicrobial may be a good indication for the use of Ulvan against various pathogens as a preservative in food processing and cosmetics and as antioxidant and antimicrobial in medicine against human pathogen.

Synthesis of azobenzene-centered (co)polymers via reversible addition-fragmentation chain transfer (RAFT) polymerization

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Yu Liping ◽  
Zhu Jian ◽  
Cheng Zhenping ◽  
Zhang Zhengbiao ◽  
Zhang Wei ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
Gel Permeation Chromatography ◽  
Polymer Chains ◽  
Dimethyl Formamide ◽  
Reversible Addition ◽  
Raft Agent ◽  
Pentablock Copolymers ◽  
Ft Ir

Abstract An azobenzene-based dithiocarbamate, 4,4'-bis[2-(carbazole-N-dithio formatyl)-2-methyl-propionatyl]-azobenzene (CDMPA), was synthesized and used as the chain transfer agent (CTA) for reversible addition-fragmentation chain transfer (RAFT) polymerization of styrene in anisole solution. Well-defined azobenzene-centered and carbazole-ended polystyrene (PS) with well-controlled molecular weight (Mn) and narrow molecular weight distributions (Mw/Mn) was obtained. The good agreement between the theoretical molecular weight (Mn,th) and the 1H NMR determined molecular weight (Mn,NMR) indicated that most of the polymer chains contained an azo-functional center-group end-capped with the carbazole moieties, which were derived from the RAFT agent. The obtained polystyrene (PS) showed a strong ultraviolet absorption in tetrahydrofuran (THF) and emitted fluorescence after excited by UV-irradiation in N,N’-dimethyl formamide (DMF) solutions. The PS was used as the macro-RAFT agent to carry out the polymerization of methyl acrylate (MA) and N-isopropylacrylamide (NIPAAM). Triblock copolymers (PMA-b-PS-b-PMA), and pentablock copolymers (PNIPAAM-b-PMA-b-PS-b-PMA-b-PNIPAAM) were obtained, respectively. These copolymers were characterized by gel permeation chromatography (GPC), FT-IR spectroscopy and NMR spectroscopy.

Preparation of Thermo-Sensitive Supramolecular Hydrogels Formed from MPEG-b-PNIPAM-b-MPEG Triblock Copolymer with α-Cyclodextrin

2014 ◽  
Vol 934 ◽  
pp. 75-79 ◽  
Author(s):  
Xiao Feng Ye ◽  
Mi Zhou ◽  
Jing Ying Hu ◽  
Xin Qian
Keyword(s):  
Triblock Copolymer ◽  
Chain Transfer ◽  
Triblock Copolymers ◽  
Raft Polymerization ◽  
Inclusion Complexation ◽  
Gel Permeation Chromatography ◽  
H Nmr ◽  
Reversible Addition ◽  
Response Interval ◽  
Gel Permeation

To develop a new drug delivery matrix with the suitable responsive interval, a well-defined triblock copolymer MPEG-b-PNIPAM-b-MPEG was synthesized by reversible addition fragmentation chain transfer (RAFT) polymerization. Then, the supramolecular hydrogels were fabricated via inclusion complexation with α-cyclodextrin (α-CD) and the triblock copolymers in aqueous solutions. The triblock copolymers were characterized by 1H NMR and gel permeation chromatography (GPC), and the supramolecular structures of hydrogels was confirmed by DSC. The resultant hydrogels was found to be thermo-sensitive, and the response interval could be modulated by controlling the content of PNIPAM.

scholarly journals Reversible Addition-Fragmentation Chain Transfer (RAFT) Polymerization of Poly(ethylmethacrylate) with Pendant Carbazole Groups

KIMIKA ◽  
2018 ◽  
Vol 29 (1) ◽  
pp. 41-50
Author(s):  
Shienna Marie Pontillas ◽  
Florentino C. Sumera ◽  
Rigoberto C. Advincula
Keyword(s):  
Molecular Weight ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
Average Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Chain Extension ◽  
Conversion Characteristic ◽  
Reversible Addition ◽  
Ft Ir ◽  
Carbazole Group

Carbazole containing polymers have captured the interest of researchers for use in optoelectronics. For an important material to exhibit its optoelectronic properties intrinsic uniformity in the molecular level is required. Thus, a monomer of ethyl methacrylate with pendant carbazole group was synthesized and polymerized via Reversible Addition-Fragmentation Chain Transfer (RAFT) to produce polymers with controlled molecular weight distribution and narrow polydispersity index (PDI). This method of polymerization was compared with that of free radical polymerization by gel permeation chromatography (GPC). The RAFT’s polymerization kinetics was observed to follow a plot of number average molecular weight (Mn) versus % conversion, characteristic of living polymerization. It was also shown to possess polymer chain extension capability. The structure of the monomer and the polymers were characterized by Fourier-Transform Infrared Spectroscopy (FT-IR) and Nuclear Magnetic Resonance (NMR).

scholarly journals Nano-Assemblies from Amphiphilic PnBA-b-POEGA Copolymers as Drug Nanocarriers

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1164
Author(s):  
Angeliki Chroni ◽  
Thomas Mavromoustakos ◽  
Stergios Pispas
Keyword(s):  
Molecular Weight ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
Polymeric Nanocarriers ◽  
Reversible Addition ◽  
2D Noesy ◽  
Drug Nanocarriers ◽  
Glycol Methyl Ether ◽  
Different Molecular Weight

The focus of this study is the development of highly stable losartan potassium (LSR) polymeric nanocarriers. Two novel amphiphilic poly(n-butyl acrylate)-block-poly(oligo(ethylene glycol) methyl ether acrylate) (PnBA-b-POEGA) copolymers with different molecular weight (Mw) of PnBA are synthesized via reversible addition fragmentation chain transfer (RAFT) polymerization, followed by the encapsulation of LSR into both PnBA-b-POEGA micelles. Based on dynamic light scattering (DLS), the PnBA30-b-POEGA70 and PnBA27-b-POEGA73 (where the subscripts denote wt.% composition of the components) copolymers formed micelles of 10 nm and 24 nm in water. The LSR-loaded PnBA-b-POEGA nanocarriers presented increased size and greater mass nanostructures compared to empty micelles, implying the successful loading of LSR into the inner hydrophobic domains. A thorough NMR (nuclear magnetic resonance) characterization of the LSR-loaded PnBA-b-POEGA nanocarriers was conducted. Strong intermolecular interactions between the biphenyl ring and the butyl chain of LSR with the methylene signals of PnBA were evidenced by 2D-NOESY experiments. The highest hydrophobicity of the PnBA27-b-POEGA73 micelles contributed to an efficient encapsulation of LSR into the micelles exhibiting a greater value of %EE compared to PnBA30-b-POEGA70 + 50% LSR nanocarriers. Ultrasound release profiles of LSR signified that a great amount of the encapsulated LSR is strongly attached to both PnBA30-b-POEGA70 and PnBA27-b-POEGA73 micelles.

Synthesis of Novel Triazole-Containing Phosphonate Polymers

2015 ◽  
Vol 68 (4) ◽  
pp. 680 ◽  
Author(s):  
Ciarán Dolan ◽  
Briar Naysmith ◽  
Simon F. R. Hinkley ◽  
Ian M. Sims ◽  
Margaret A. Brimble ◽  
...  
Keyword(s):  
Chain Transfer ◽  
Click Reaction ◽  
Raft Polymerization ◽  
Ethyl Acrylate ◽  
Polymer Chemistry ◽  
Synthesis And Characterization ◽  
Reversible Addition

The objective of this research was to develop novel phosphonate-containing polymers as they remain a relatively under researched area of polymer chemistry. Herein, we report the synthesis and characterization of 2-(1-(2-(diethoxyphosphoryl)ethyl)-1H-1,2,3-triazol-4-yl)ethyl acrylate (M1) and diethyl (2-(4-(2-acrylamidoethyl)-1H-1,2,3-triazol-1-yl)ethyl)phosphonate (M2) monomers using the copper-catalyzed azide–alkyne cycloaddition (CuAAC) ‘click’ reaction, and their subsequent polymerization via both uncontrolled and reversible addition–fragmentation chain transfer (RAFT) polymerization techniques yielding phosphonate polymers (P1–P4).

SYNTHESIS AND CHARACTERIZATION OF POLYURETHANE ACRYLATES FOR UV CURABLE COATING AGENTS

2007 ◽  
Vol 14 (04) ◽  
pp. 713-717
Author(s):  
MI NA PARK ◽  
YOUNG SOO KANG ◽  
SUN WHA OH ◽  
BYUNG HYUN AHN ◽  
MYUNG JUN MOON
Keyword(s):  
Ir Spectroscopy ◽  
Chain Transfer ◽  
Synthesis And Characterization ◽  
Dibutyltin Dilaurate ◽  
Urethane Acrylate ◽  
Uv Curable ◽  
Ft Ir ◽  
Coating Agents ◽  
Ft Ir Spectroscopy

The single hydroxyl-terminated urethane acrylate oligomers were synthesized from 2-mercaptoethanol (2-MEOH), alkyl (methyl, butyl, and 2-ethylhexyl) acrylate, and 2,2-azobisisobutyronitrile (AIBN, initiator), with dibutyltin dilaurate (DBTDL) as a catalyst. 2-MEOH was used as a functional chain transfer agent. Poly(alkyl urethane) acrylate oligomers were obtained by the reaction of single hydroxyl-terminated polyalkyl acrylates and 2-isocyanatoethyl acrylate. They were characterized by NMR, FT-IR spectroscopy, rheometer, and DSC. Because poly(alkyl urethane) acrylate oligomers have lower Tg and viscosity than hydroxyl-terminated polyalkyl acrylate oligomers (HTPAO) non-containing urethane groups, they can be used for ultraviolet (UV) curable coatings, inks, and adhesives.

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