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 and characterization of high molecular weight and low dispersity polystyrene homopolymers by RAFT polymerization

e-Polymers ◽  
2012 ◽  
Vol 12 (1) ◽  
Author(s):  
Cheng Jin ◽  
Chun Liu ◽  
Bo Jiang ◽  
Qin-jian in
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
Polymerization Temperature ◽  
Polymer Molecular Weight ◽  
Mild Conditions ◽  
Reversible Addition ◽  
Polymerization Method

AbstractHigh molecular weight polystyrene homopolymers with low dispersity were synthesized by a reversible addition-fragmentation chain transfer (RAFT) polymerization method using 0.03 and 0.3 wt% of cumyl dithiobenzoate (CDB) vs. styrene (St) and the azobis(isobutyronitrile) initiator, at the polymerization temperature of 60 or 70 °C. The optimal high molecular weight polystyrene via this synthetic scheme shows Mw = 46.5×104, Mn = 33.3×104, and a dispersity of 1.40. The polystyrene chain contains a dithiobenzoate C=S moiety and thus can be used as a macro-chain-transfer agent for the polymerization of other monomers and for the synthesis of diversified block copolymers under mild conditions. The changes of the polystyrene molecular weight and dispersity were studied by the influences of the initial concentration ratio of CDB to styrene ([CDB]0/[St]0), the polymerization temperature, and the polymerization time. The PS molecular weight is inversely proportional to the [CDB]0/[St]0 ratio. Decreasing CDB from 0.3 to 0.03 wt%, a high MW PS was obtained, while the dispersity was observed to increase from 1.10 to 1.40. The PS molecular weight increases with the increase of the reaction time, while the dispersity of PS varies little from 1.12 to 1.23. The molecular weight and dispersity increase with the increase of the polymerization temperature. As the temperature arises from 60°C to 70°C, the conversion increases considerably from 25.8% to 39.9%, and the dispersity increases slightly from 1.15 to 1.17. As the temperature reaches 80°C, the conversion increases considerably to 64.7%, and the dispersity increases to 1.53. The polymer molecular weight of the polystyrene prepared by the RAFT method is suitable for the applications of engineering materials.

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).

scholarly journals Synthesis and characterization of triphenylamine and Bbis(indolyl)methane center-functionalized polymer via reversible addition-fragmentation chain transfer polymerization

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Jie Xu ◽  
Wei Shang ◽  
Jian Zhu ◽  
Zhenping Cheng ◽  
Nianchen Zhou ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
Chloroform Solution ◽  
Monomer Conversion ◽  
Benzyl Ester ◽  
Chain Extension ◽  
Reversible Addition ◽  
Raft Agent ◽  
Cyclic Voltammetry Method

AbstractA novel bis-functional reversible addition-fragmentation chain transfer (RAFT) agent bearing triphenylamine (TPA) and bis(indolyl)methane (BIM) groups, {4-[bis(1-carbodithioic acid benzyl ester-indol-3-yl)methyl]phenyl}diphenylamine (BCIMPDPA), was synthesized and successfully used as the RAFT agent to mediate the polymerization of styrene (St). The polymerization results showed that reversible addition-fragmentation chain transfer (RAFT) polymerization of St could be well controlled. The kinetic plot showed it was of first order and the numberaverage molecular weight (Mn(GPC)) of the polymer measured by GPC increased linearly with monomer conversion, simultaneously, the molecular weight distribution of the polymer was also relatively narrow. In addition, the existence of the TPA and BIM groups in the middle of polymer chain was confirmed by chain extension reaction and 1H NMR spectrum. The optical properties of the functionalized polystyrene (PS) in chloroform solution were also investigated. Furthermore, the redox process of the RAFT agent and the functionalized PS were studied by cyclic voltammetry method.

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.

Synthesis of Novel Triazole-Containing Phosphonate Polymers

2020 ◽  
Author(s):  
C Dolan ◽  
B Naysmith ◽  
Simon Hinkley ◽  
Ian Sims ◽  
MA Brimble ◽  
...  
Keyword(s):  
Chain Transfer ◽  
Click Reaction ◽  
Raft Polymerization ◽  
Ethyl Acrylate ◽  
Polymer Chemistry ◽  
Synthesis And Characterization ◽  
Reversible Addition

© 2015 CSIRO. 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).

Reversible addition fragmentation chain transfer (RAFT) polymerization of styrene in fluid CO2

e-Polymers ◽  
2004 ◽  
Vol 4 (1) ◽  
Author(s):  
Toshihiko Arita ◽  
Sabine Beuermann ◽  
Michael Buback ◽  
Philipp Vana
Keyword(s):  
Chain Transfer ◽  
Raft Polymerization ◽  
Molecular Weights ◽  
Reversible Addition ◽  
Significant Difference ◽  
Raft Agent ◽  
Successful Control ◽  
A Minor ◽  
Peak Widths

Abstract Reversible addition fragmentation chain transfer (RAFT) polymerizations of styrene in fluid CO2 have been carried out at 80°C and 300 bar using cumyl dithiobenzoate as the controlling agent in the concentration range of 3.5·10-3 to 2.1·10-2 mol/L. This is the first report on RAFT polymerization in fluid CO2. The polymerization rates were retarded depending on the employed RAFT agent concentration with no significant difference between the RAFT polymerization performed in fluid CO2 and in toluene. Full chain length distributions were analyzed with respect to peak molecular weights, indicating the successful control of radical polymerization in fluid CO2. A characterization of the peak widths may suggest a minor influence of fluid CO2 on the addition reaction of macroradicals on the dithiobenzoate group.

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