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.

Synthesis of Zwitterionic Chimeric Polymersomes for Efficient Protein Loading and Intracellular Delivery

2021 ◽  
Author(s):  
bingbing zhao ◽  
Yuting Yan ◽  
Junmei Zhang ◽  
Enping Chen ◽  
Ke Wang ◽  
...  
Keyword(s):  
Ring Opening ◽  
Triblock Copolymer ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
Intracellular Delivery ◽  
Ring Opening Polymerization ◽  
H Nmr ◽  
Protein Loading ◽  
Reversible Addition

A novel zwitterionic triblock copolymer of poly(dimethylamino carbonate)-polycaprolactone-poly((2-(methacryloyloxy)ethyl)dimethyl-(3-sulfopropyl)ammonium) [PAC(DMA)-PCL-PMDMSA] was designed and synthesized via sequential ring-opening polymerization (ROP) and reversible addition-fragmentation chain transfer (RAFT) polymerization successively. The 1H NMR and...

Synthesis, self-assembly and self-healing properties of organic–inorganic ABA triblock copolymers with poly(POSS acrylate) endblocks

2019 ◽  
Vol 10 (19) ◽  
pp. 2424-2435 ◽  
Author(s):  
Bingjie Zhao ◽  
Sen Xu ◽  
Sixun Zheng
Keyword(s):  
Self Assembly ◽  
Triblock Copolymer ◽  
Chain Transfer ◽  
Triblock Copolymers ◽  
Raft Polymerization ◽  
Self Healing ◽  
Reversible Addition ◽  
Aba Triblock Copolymer

A novel organic–inorganic ABA triblock copolymer with a poly(acrylate amide) (PAA) midblock and poly(POSS acrylate) [P(POSS)] endblocks was synthesized via sequential reversible addition–fragmentation chain transfer (RAFT) polymerization.

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.

Synthesis of Polystyrene-b-poly(n-butyl acrylate)-b-Polystyrene Triblock Copolymers as Binder for Pigment Dyeing

2012 ◽  
Vol 441 ◽  
pp. 473-477
Author(s):  
Lei Yang ◽  
Cheng Jie Hu ◽  
Hai Yang ◽  
Dong Ming Qi
Keyword(s):  
Mechanical Properties ◽  
Butyl Acrylate ◽  
Triblock Copolymer ◽  
Chain Transfer ◽  
Triblock Copolymers ◽  
Polymerization Process ◽  
Fastness Properties ◽  
Copolymer Films ◽  
Reversible Addition ◽  
Dyed Fabrics

Well-controlled polystyrene-b-poly (n-butyl acrylate)-b-polystyrene (PSt-b-PnBA-b-PSt) triblock copolymers were prepared by RAFT (reversible addition-fragmentation chain transfer) emulsion polymerization process. The mechanical properties of the triblock copolymers were investigated in comparison to the P(nBA-co-St) statistical copolymers. When the PSt content is 20%, the ultimate tensile strength of triblock copolymer is nearly six times the strength of statistical copolymer, while their modulus are all around 3.0×103 Pa. The triblock copolymer films feel smooth and non-tacky as the PSt content is higher than 20%. It indicates that PSt-b-PnBA-b-PSt triblock copolymers can be used as binders in pigment dyeing, providing the dyed fabrics with soft non-tacky handle and good fastness properties.

Bioconjugation of papain with poly(N-vinylpyrrolidone): NMR characterization and study of its enzymatic activity

2021 ◽  
Vol 99 (1) ◽  
pp. 10-17
Author(s):  
L.E. Verduzco ◽  
Ana L. García-Pérez ◽  
Ramiro Guerrero-Santos ◽  
Antonio Ledezma-Pérez ◽  
Jorge Romero-García ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Catalytic Activity ◽  
Chain Transfer ◽  
Gel Permeation Chromatography ◽  
Acid Group ◽  
H Nmr ◽  
Reversible Addition ◽  
Nmr Characterization ◽  
Vis Spectroscopy ◽  
C Nmr

A poly(vinylpyrrolidone) end-functionalized with a carboxylic acid group (PVP–CO2H) was synthesized by reversible addition-fragmentation chain transfer (RAFT)/macromolecular design via the interchange of xanthates (MADIX) polymerization mediated by 4-(O-ethylxanthyl)methyl benzoic acid. The molecular weight of the as-synthesized PVP–CO2H was estimated through UV–vis spectroscopy (Mn(UV–vis) = 7322 g/mol), gel permeation chromatography (GPC) (Mn(GPC) = 8670 g/mol), and 1H NMR, (Mn(NMR) = 8207 g/mol). The values obtained were close with the theoretical molecular weight (Mn(th) = 7925 g/mol). Subsequently, the preformed PVP–CO2H was activated to produce N-succinimidyl poly(vinylpyrrolidone) (PVP–NHS). This precursor was covalently coupled to papain to produce bioconjugate PVP–papain. The functional group modifications in the PVP chain-end were observed by the variations in the chemical shift values by 1H and 13C NMR and FTIR analysis at each step of the synthesis. The molecular weight of the PVP–papain was obtained by SEC–HPLC and suggests that, on average, four or five chains of PVP–CO2H were attached to one papain molecule. Compared with papain, the PVP–papain exhibited significantly improved catalytic activity, pH, and thermal stability. Additionally, the storage studies showed that the catalytic activity of PVP–papain was about 79% versus the native enzyme (29%), and this activity was maintained even when it was stored for 25 days.

Enzyme catalysis-induced RAFT polymerization in water for the preparation of epoxy-functionalized triblock copolymer vesicles

2018 ◽  
Vol 9 (39) ◽  
pp. 4908-4916 ◽  
Author(s):  
Qin Xu ◽  
Yuxuan Zhang ◽  
Xueliang Li ◽  
Jun He ◽  
Jianbo Tan ◽  
...  
Keyword(s):  
Enzyme Catalysis ◽  
Triblock Copolymer ◽  
Room Temperature ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
Reversible Addition

Enzyme catalysis-induced aqueous reversible addition–fragmentation chain transfer (RAFT) polymerization was conducted at room temperature for the preparation of epoxy-functionalized triblock copolymer vesicles.

Synthesis and characterization of poly(vinyl chloride-graft-2-vinylpyridine) graft copolymers using a novel macroinitiator by reversible addition-fragmentation chain transfer polymerization

e-Polymers ◽  
2014 ◽  
Vol 14 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Temel Öztürk ◽  
Melahat Göktaş ◽  
Bedrettin Savaş ◽  
Mustafa Işıklar ◽  
Mehmet Nuri Atalar ◽  
...  
Keyword(s):  
Vinyl Chloride ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
Graft Copolymers ◽  
Monomer Concentration ◽  
Polymerization Reaction ◽  
Scanning Calorimetry ◽  
H Nmr ◽  
Poly Vinyl Chloride ◽  
Reversible Addition

AbstractSynthesis of poly(vinyl chloride-graft-2-vinylpyridine) graft copolymers was carried out by reversible addition-fragmentation chain transfer (RAFT) polymerization of 2-vinylpyridine using a novel macroinitiator (RAFT macroinitiator). For this purpose, RAFT macroinitiator was obtained from the potassium salt of ethyl xanthogenate and poly(vinyl chloride) (PVC). Then the graft copolymers were synthesized by using RAFT macroinitiator and 2-vinylpyridine. The principal parameters such as monomer concentration, initiator concentration, and polymerization time that affect the polymerization reaction were studied. The effect of the reaction conditions on the heterogeneity index and molecular weight was also investigated. The block lengths of the graft copolymers were calculated by using 1H nuclear magnetic resonance (1H NMR) spectra. The block lengths of the copolymers could be adjusted by varying the monomer and initiator concentrations. The characterizations of the samples were carried out by using 1H NMR, Fourier-transform infrared spectroscopy, gel-permeation chromatography, thermogravimetric analysis, differential scanning calorimetry, and fractional precipitation (γ value) techniques. RAFT polymerization is used to control the polymerization of 2-vinylpyridine over a broad range of molecular weights.

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.

Synthesis of Allyl-Functionalized Polymers via Selective Reversible Addition-Fragmentation Chain Transfer (RAFT) Polymerization

2014 ◽  
Vol 924 ◽  
pp. 65-68
Author(s):  
Zhan Jun Liu ◽  
Ming Fei Zhao ◽  
Zhen Gang Wu ◽  
Gang Han
Keyword(s):  
Chain Transfer ◽  
Raft Polymerization ◽  
Functionalized Polymers ◽  
Side Chains ◽  
Double Bonds ◽  
H Nmr ◽  
Reversible Addition ◽  
Allyl Methacrylate

Allyl-functionalized copolymers with well-defined structure have been successfully prepared via selective reversible addition-fragmentation chain transfer (RAFT) copolymerization of styrene and allyl methacrylate possessing a higher reactive methacrylate and a lower reactive allyl. By employing a fast RAFT equilibrium, the polymerization for AMA completely occurred in methacrylate double bonds, whereas allyl double bonds remained intact and were introduced into the side-chains. GPC and 1H NMR analyses have confirmed the high chain-end functionality of the resultant copolymer.

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