SYNTHESIS OF POLY[(ε-CL)-co-(GA-alt-L-Asp)] COPOLYMER AND EFFECTS ON CELLS AFTER COUPLING WITH SMALL PEPTIDE

2015 ◽  
Vol 27 (06) ◽  
pp. 1550053
Author(s):  
Na Qiang ◽  
Fang Xie ◽  
Hao Liang ◽  
Xian-Feng Li ◽  
Shuo Tang ◽  
...  
Keyword(s):  
Ring Opening ◽  
Gel Permeation Chromatography ◽  
Ring Opening Polymerization ◽  
Carboxyl Groups ◽  
Structure And Properties ◽  
Small Peptide ◽  
Scanning Calorimetry ◽  
Beneficial Effects ◽  
Structural Regularity ◽  
Gel Permeation

A novel poly[([Formula: see text]-CL)-co-(GA-alt-L-Asp)] with improved hydrophilicity was prepared. The monomer 3(S)-[(benzyloxycarbony)methyl]-1,4-dioxane-2,5-dione (BMD) was prepared from aspartic acid. The polymer was obtained by ring-opening polymerization of [Formula: see text]-caprolactone ([Formula: see text]-CL) and BMD. Poly[([Formula: see text]-CL)-co-(GA-alt-L-Asp)] was synthesized by deprotection. The structure and properties of the polymer were characterized using 1H nuclear magnetic resonance, gel permeation chromatography, and differential scanning calorimetry. The melting point and melting enthalpy of the polymer decreased with the increase of BMD. The structural regularity of polycaprolactone was destroyed by the BMD. A laminin-derived peptide [i.e., Arg-Gly-Asp (RGD)] was covalently tethered to the carboxyl groups and the peptide-grafted films. Results indicated that the addition of RGD had beneficial effects for cell growth, as shown by scanning electron microscopy.

scholarly journals 1-n-Butyl-3-methylimidazolium-2-carboxylate: a versatile precatalyst for the ring-opening polymerization of ε-caprolactone and rac-lactide under solvent-free conditions

2013 ◽  
Vol 9 ◽  
pp. 647-654 ◽  
Author(s):  
Astrid Hoppe ◽  
Faten Sadaka ◽  
Claire-Hélène Brachais ◽  
Gilles Boni ◽  
Jean-Pierre Couvercelle ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Ring Opening ◽  
Gel Permeation Chromatography ◽  
Ring Opening Polymerization ◽  
Solvent Free ◽  
Scanning Calorimetry ◽  
H Nmr ◽  
Solvent Free Conditions ◽  
Gel Permeation

The ring-opening polymerization of ε-caprolactone (ε-CL) and rac-lactide (rac-LA) under solvent-free conditions and using 1-n-butyl-3-methylimidazolium-2-carboxylate (BMIM-2-CO2) as precatalyst is described. Linear and star-branched polyesters were synthesized by successive use of benzyl alcohol, ethylene glycol, glycerol and pentaerythritol as initiator alcohols, and the products were fully characterized by 1H and 13C{1H} NMR spectroscopy, gel permeation chromatography (GPC), and differential scanning calorimetry (DSC). BMIM-2-CO2 acts as an N-heterocyclic carbene precursor, resulting from in situ decarboxylation, either by heating under vacuo (method A) or by addition of NaBPh4 (method B). Possible catalytic and deactivation mechanisms are proposed.

Novel Amphiphilic Star-Shaped Poly(2-Oxazoline)s with Calix[4]Arene Branching Center

2021 ◽  
Vol 899 ◽  
pp. 300-308
Author(s):  
Aleksei N. Blokhin ◽  
Alla B. Razina ◽  
Andrey V. Tenkovtsev
Keyword(s):  
Aqueous Solutions ◽  
Ring Opening ◽  
Gel Permeation Chromatography ◽  
Ring Opening Polymerization ◽  
Arene Derivative ◽  
Vis Spectroscopy ◽  
Gel Permeation ◽  
Grafting From ◽  
Cationic Ring Opening Polymerization

Novel amphiphlic four-arm star-shaped poly (2-alkyl-2-oxazoline) s with calix [4] arene core were synthesized using the “grafting from” approach. The chlorosulfonated calix [4] arene derivative was synthesized and successfully applied as a multifunctional initiator for the cationic ring-opening polymerization of 2-alkyl-2-oxazolines. Obtained star-shaped poly (2-alkyl-2-oxazoline) s were characterized by means of NMR, UV-Vis spectroscopy and gel-permeation chromatography. It was shown that star-shaped poly (2-isopropyl-2-oxazoline) perform thermosensitivity in aqueous solutions.

scholarly journals Ring-opening polymerization and plasticization of poly(L-lactic)acid by adding of glycerol-dioleate

2021 ◽  
Author(s):  
Tibor Horváth ◽  
Kálmán Marossy ◽  
Tamás J. Szabó
Keyword(s):  
Lactic Acid ◽  
Glass Transition ◽  
Ring Opening ◽  
Chemical Properties ◽  
Gel Permeation Chromatography ◽  
Ring Opening Polymerization ◽  
General Information ◽  
Scanning Calorimetry ◽  
Different Temperatures ◽  
Physical And Chemical

AbstractPoly-L-lactic acid (PLLA) has been produced by ring-opening polymerization method. During the polymerization processes different temperatures and process times have been applied to reach an optimum setup that was used to produce sample. The sample was measured by Fourier-transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC) and differential scanning calorimetry (DSC) methods to identify the structure, molar mass and define the glass transition temperatures of product and obtain general information about the physical and chemical properties of material. Based on the results of measures, the material’s crystallinity was also investigated. The plasticization of PLLA has been also investigated. During the experiments, previously produced material (PLLA synthesized by polycondensation) was plasticised by adding of glycerol-dioleate. The plasticized material was also measured by FTIR, GPC and DSC methods to check the basic physical and chemical parameters of the material. According to the results of the measurements that were found, by this approach, the glass transition temperature of PLLA was reduced by 7 °C that indicated the glycerol-dioleate might act as a plasticizer for PLLA material without any deviation in the chemical structure of material.

Synthesis and Characterization of a Novel Biodegradable Polymer with Fluorescence Property

2011 ◽  
Vol 197-198 ◽  
pp. 21-26
Author(s):  
Ji Hang Li ◽  
Dong Jian Shi ◽  
Na Hu ◽  
Wei Fu Dong ◽  
Jun Feng Li ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Ring Opening ◽  
Gel Permeation Chromatography ◽  
Ring Opening Polymerization ◽  
Fluorescence Property ◽  
H Nmr ◽  
Gel Permeation ◽  
Fluorescent Polymer ◽  
Poor Solvent

In this paper, a novel biodegradable and fluorescent polymer: fluorescein-polylactide (FL-PLA) was synthesized by FL and lactide in the method of ring-opening polymerization with the catalysis of Sn(Oct)2under 130°C . The structure and molecular weight of FL-PLA were characterized by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (1H-NMR) spectroscopy, and gel permeation chromatography (GPC). The molecular weight of FL-PLA increased from 9.03×103to 21.24×103with decreasing the amount of FL and kept a narrow distribution. The result of differential scanning calorimeter (DSC) showed that Tgincreased from 52 to 72°C with increasing the molecular weight of polymer. Moreover, the average number content of FL in each molecular chain decreased from 0.96 to 0.81 with decrement of the amount of FL. Furthermore, FL-PLA showed the fluorescence property, and the fluorescence intensity could be controlled by the amount of FL. The FL-PLA nanoparticles were prepared by mixing the good and poor solvent, and the diameter was about 3 μm with regular spherical morphology.

Synthesis and characterization of 4- and 6-arm star-shaped poly(ε-caprolactone)s

e-Polymers ◽  
2005 ◽  
Vol 5 (1) ◽  
Author(s):  
Michael A. R. Meier ◽  
Ulrich S. Schubert
Keyword(s):  
Ring Opening ◽  
Analytical Techniques ◽  
Gel Permeation Chromatography ◽  
Laser Desorption ◽  
Ring Opening Polymerization ◽  
Molecular Weights ◽  
H Nmr ◽  
Flight Mass Spectrometry ◽  
Gel Permeation

AbstractStar-shaped poly(ε-caprolactone) (PCL) polymers were synthesized and fully characterized by gel permeation chromatography, matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) as well as 1H NMR spectroscopy. First a series of four-armed PCLs with different molecular weights was prepared and analyzed with the mentioned analytical techniques revealing that the applied ring-opening polymerization was controlled and defined star-shaped polymers could be synthesized. Subsequently, also the synthesis of six-armed PCL polymers was investigated with the conclusion that also these starshaped polymers could be prepared in a controlled fashion.

Lactide synthesis optimization: investigation of the temperature, catalyst and pressure effects

e-Polymers ◽  
2014 ◽  
Vol 14 (5) ◽  
pp. 353-361 ◽  
Author(s):  
Morteza Ehsani ◽  
Khosrow Khodabakhshi ◽  
Mohammad Asgari
Keyword(s):  
Molecular Weight ◽  
Ring Opening ◽  
Batch Reactor ◽  
Analytical Techniques ◽  
Gel Permeation Chromatography ◽  
Ring Opening Polymerization ◽  
Pressure Effects ◽  
Synthesis Rate ◽  
Antimony Trioxide ◽  
Scanning Calorimetry

AbstractThe most applicable method to produce polylactic acid (PLA) is via ring opening polymerization of lactide, which involves three steps: polycondensation of low-molecular-weight PLA (LMW PLA), depolymerization or dimerization of a prepolymer into a cyclic dimer of lactic acid (lactide) and ring opening polymerization of lactide to achieve high-molecular-weight PLA. This work aimed to optimize the reaction conditions of lactide synthesis. Reactions at different temperatures and pressures were carried out in the presence of tin (II) oxide, tin (II) chloride, tin (II) octate, antimony trioxide, sulfuric acid and no catalyst in a semi-batch reactor. Different analytical techniques such as gas chromatography, gel permeation chromatography, differential scanning calorimetry, nuclear magnetic resonance and Fourier transform infrared spectroscopy have been used to evaluate the LMW PLA properties, rate of lactide synthesis and racemization. Results showed that the highest rate of conversion occurred in the presence of tin (II) chloride and octate. Synthesis rate increased with the increase in reaction temperature and the decrease in pressure. Increasing temperature also resulted in higher amounts of optical and chemical impurities in the crude lactide.

scholarly journals Formation of cyclic structures in the cationic ring-opening polymerization of 1,3-dioxolane

RSC Advances ◽  
2020 ◽  
Vol 10 (16) ◽  
pp. 9623-9632
Author(s):  
Anna M. J. Coenen ◽  
Jules A. W. Harings ◽  
Samaneh Ghazanfari ◽  
Stefan Jockenhoevel ◽  
Katrien V. Bernaerts
Keyword(s):  
Ring Opening ◽  
Gel Permeation Chromatography ◽  
Laser Desorption ◽  
Ring Opening Polymerization ◽  
Laser Desorption Ionization ◽  
Ionization Time ◽  
Flight Mass Spectrometry ◽  
Gel Permeation ◽  
Cationic Ring Opening Polymerization ◽  
Matrix Assisted Laser

Elucidating the mechanism of the cationic ring-opening polymerization of dioxolane using gel permeation chromatography, matrix assisted laser desorption/ionization time of flight mass spectrometry and 31P NMR.

Preparation and properties of fluorosilicone and fluorosilicone elastomer with various contents of trifluoropropyl groups

e-Polymers ◽  
2011 ◽  
Vol 11 (1) ◽  
Author(s):  
Yan Cui ◽  
Wenge Jiang ◽  
Dongmei Li ◽  
Chengqun Niu ◽  
Shengyu Feng ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Ring Opening ◽  
Gel Permeation Chromatography ◽  
Scanning Calorimetry ◽  
Solvent Resistance ◽  
Glass Transition Temperatures ◽  
Methyl Vinyl ◽  
Dsc Measurements ◽  
Gel Permeation ◽  
Thermal Stability Of

AbstractPoly(dimethyl-methyltrifluoropropyl-methylvinyl)siloxanes (PFMVS) with various contents of trifluoropropyl groups were prepared by ring-opening copolymerization of 2,4,6-trimethyl-2,4,6-tris(3,3,3-trifluoropropyl) cyclotrisiloxane (D3F), octamethylcyclotetrasiloxane (D4) and 1,3,5,7-tetramethyl tetravinylcyclotetrasiloxane (D4Vi). All the polymers were characterized by IR, 1HNMR, 29SiNMR, gel permeation chromatography (GPC), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC) measurements. The results show that methyltrifluoropropyl-siloxane units in the copolymer can disrupt the molecular regularity and lead to noncrystalline copolymers with low glasstransition temperatures. Moreover, the onset temperatures of thermal degradation and the glass transition temperatures of polymers decrease gradually with the content of trifluoropropyl groups increasing. Then the thermal stability and solvent resistance of elastomers based on PFMVSs were measured. The data of TGA indicate that the thermal stability of fluorosilicone elastomers are less than conventional methyl vinyl silicone rubber (MVQ), but the fluorosilicone elastomers have outstanding solvent resistance. The content of the trifluoropropyl groups influences the performances of elastomer to a certain degree.

Redox-active polymer-nanoparticle hybrid materials

2000 ◽  
Vol 72 (1-2) ◽  
pp. 67-72 ◽  
Author(s):  
Keith J. Watson ◽  
Jin Zhu ◽  
SonBinh T. Nguyen ◽  
Chad A. Mirkin
Keyword(s):  
Gold Nanoparticles ◽  
Block Copolymers ◽  
Hybrid Materials ◽  
Ring Opening ◽  
Gel Permeation Chromatography ◽  
Polymer Chains ◽  
Electrochemical Studies ◽  
Redox Active ◽  
Gel Permeation ◽  
Current Rectification

Ring-opening metathesis polymerization was used to modify organic soluble gold nanoparticles with redox-active polymers. A gel-permeation chromatography study revealed that each nanoparticle is modified with approximately 11 polymer chains. Electrochemical studies of nanoparticles modified with block copolymers of two different redox-active groups revealed that each monomer is electrochemically accessible, while no current rectification was observed.

Characterization of bi-layered magnetic nanoparticles synthesized via two-step surface-initiated ring-opening polymerization

2015 ◽  
Vol 87 (11-12) ◽  
pp. 1085-1097 ◽  
Author(s):  
Li Wang ◽  
Stefan Baudis ◽  
Karl Kratz ◽  
Andreas Lendlein
Keyword(s):  
Magnetic Nanoparticles ◽  
Ring Opening ◽  
Average Molecular Weight ◽  
Polymer Networks ◽  
Gel Permeation Chromatography ◽  
Degree Of Crystallinity ◽  
Scanning Calorimetry ◽  
H Nmr ◽  
Transmission Electron

AbstractA versatile strategy to integrate multiple functions in a polymer based material is the formation of polymer networks with defined nanostructures. Here, we present synthesis and comprehensive characterization of covalently surface functionalized magnetic nanoparticles (MNPs) comprising a bi-layer oligomeric shell, using Sn(Oct)2 as catalyst for a two-step functionalization. These hydroxy-terminated precursors for degradable magneto- and thermo-sensitive polymer networks were prepared via two subsequent surface-initiated ring-opening polymerizations (ROPs) with ω-pentadecalactone and ε-caprolactone. A two-step mass loss obtained in thermogravimetric analysis and two distinct melting transitions around 50 and 85°C observed in differential scanning calorimetry experiments, which are attributed to the melting of OPDL and OCL crystallites, confirmed a successful preparation of the modified MNPs. The oligomeric coating of the nanoparticles could be visualized by transmission electron microscopy. The investigation of degrafted oligomeric coatings by gel permeation chromatography and 1H-NMR spectroscopy showed an increase in number average molecular weight as well as the presence of signals related to both of oligo(ω-pentadecalactone) (OPDL) and oligo(ε-caprolactone) (OCL) after the second ROP. A more detailed analysis of the NMR results revealed that only a few ω-pentadecalactone repeating units are present in the degrafted oligomeric bi-layers, whereby a considerable degree of transesterification could be observed when OPDL was polymerized in the 2nd ROP step. These findings are supported by a low degree of crystallinity for OPDL in the degrafted oligomeric bi-layers obtained in wide angle X-ray scattering experiments. Based on these findings it can be concluded that Sn(Oct)2 was suitable as catalyst for the preparation of nanosized bi-layered coated MNP precursors by a two-step ROP.

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