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

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.

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Living free radical polymerization of styrene with 2-cyanoprop-2-yl dithionaphthalate as RAFT agent

e-Polymers ◽

10.1515/epoly.2003.3.1.576 ◽

2003 ◽

Vol 3 (1) ◽

Author(s):

Zhu Jian ◽

Zhu Xiulin ◽

Zhou Di ◽

Chen Jianying

Keyword(s):

Molecular Weight ◽

Reaction Temperature ◽

Raft Polymerization ◽

Monomer Concentration ◽

Gel Permeation Chromatography ◽

Monomer Conversion ◽

Bulk Polymerization ◽

Polymerization Rate ◽

Chain Extension ◽

Raft Agent

Abstract The reversible addition-fragmentation chain transfer (RAFT) bulk polymerization of styrene was studied using 2-cyanoprop-2-yl dithionaphthalate (CPDN) as RAFT agent in the presence or absence of 2,2’-azoisobutyronitrile (AIBN). The results of both thermally and AIBN-initiated styrene (St) polymerizations show that St can be polymerized in a controlled way using CPDN as RAFT agent; i.e., the polymerization rate is first order with respect to monomer concentration, and molecular weight increases linearly with monomer conversion. The molecular weights obtained from gel permeation chromatography are close to the theoretical values and molecular weight distributions are relatively narrow (Mw/Mn < 1.2). It is confirmed by chain extension reaction that the polymer prepared via RAFT polymerization can be used as a macroRAFT agent. The effects of reaction temperature and mole ratios [St]0/[CPDN]0/[AIBN]0 on the polymerization were investigated. The results indicate that the reaction temperature has a positive effect on the polymerization rate, but little effect on molecular weight and molecular weight distribution, and the optimum mole ratios were found to be [CPDN]0/[AIBN]0 > 4/3 and [St]0/[CPDN]0 < 800.

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

e-Polymers ◽

10.1515/epoly.2007.7.1.1059 ◽

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.

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Synthesis and Characterization of well Defined Polychloroprene by RAFT Polymerization

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.787.241 ◽

2013 ◽

Vol 787 ◽

pp. 241-244

Author(s):

Jia Hui ◽

Yan Shi ◽

Zhi Feng Fu

Keyword(s):

Molecular Weight ◽

Raft Polymerization ◽

Average Molecular Weight ◽

Reaction Times ◽

Monomer Conversion ◽

H Nmr ◽

Molecular Weight Distributions ◽

Reversible Addition ◽

Raft Agent ◽

Active Nature

Well defined polychloroprene has been synthesized by reversible addition fragmentation chain transfer (RAFT) polymerization with 2-(ethoxycarbonyl) prop-2-yl dithiobenzoate (EPDTB) as RAFT agent, AIBN as initiator, Chloroprene as monomer. Polymerization with two different feed ratios of monomer to RAFT agent were carried out. The sampling products at different reaction times were characterized using GPC and 1H-NMR. The GPC results demonstrated the molecular weight distributions (Mw/Mn) were narrow, and the number average molecular weight (Mn) was developed linearly with monomer conversion. All the characteristic signals of polychloroprene with the EPDTB as terminal groups were clearly observed in the 1H-NMR spectrum. In addition, the chain-extended polymers were also obtained successfully using the macro-RAFT agent, which indicated the active nature of the chain end.

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

KIMIKA ◽

10.26534/kimika.v29i1.41-50 ◽

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).

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Dendrimers as Scaffolds for Reversible Addition Fragmentation Chain Transfer (RAFT) Agents: a Route to Star-Shaped Block Copolymers

Australian Journal of Chemistry ◽

10.1071/ch05036 ◽

2005 ◽

Vol 58 (6) ◽

pp. 483 ◽

Cited By ~ 26

Author(s):

Xiaojuan Hao ◽

Eva Malmström ◽

Thomas P. Davis ◽

Martina H. Stenzel ◽

Christopher Barner-Kowollik

Keyword(s):

Molecular Weight ◽

Block Copolymers ◽

Butyl Acrylate ◽

Chain Transfer ◽

Raft Polymerization ◽

Star Polymers ◽

Size Exclusion ◽

Chain Extension ◽

Reversible Addition ◽

Star Block Copolymers

Star-shaped block copolymers of styrene and n-butyl acrylate having three, six, and twelve pendent arms were successfully synthesized via reversible addition fragmentation chain transfer (RAFT) polymerization. Dendritic cores (based on 1,1,1-trimethylolpropane) of generation 0, 1, and 2 have been functionalized with 3-benzylsulfanylthiocarbonylsulfanylpropionic ester groups and have subsequently been employed to mediate the polymerization of styrene and n-butyl acrylate to generate macro-star-RAFT agents as starting materials for chain extension. The chain extension of the macro-star-RAFT agents with either styrene or n-butyl acrylate by bulk free radical polymerization at 60°C gives narrowly distributed polymer (final polydispersities close to 1.2) increasing linearly in molecular weight with increasing monomer-to-polymer conversion. However, with an increasing number of arms (i.e., when going from three- to twelve-armed star polymers), the chain extension becomes significantly less efficient. The molecular weight of the generated block copolymers was assessed using 1H NMR spectroscopy as well as size exclusion chromatography calibrated with linear polystyrene standards. The hydrodynamic radius, Rh, of the star block copolymers as well as the precursor star polymers was determined in tetrahydrofuran by dynamic light scattering (90°) at 25°C. Interestingly, the observed Rh–Mn relationships indicate a stronger dependence of Rh on Mn for poly(butyl acrylate) stars than for the corresponding styrene polymers. Rh increases significantly when the macro-star-RAFT agent is chain extended with either styrene or n-butyl acrylate.

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

Polymers ◽

10.3390/polym13071164 ◽

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.

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Synthesis and characterization of a naphthalimide–dye end-labeled copolymer by reversible addition–fragmentation chain transfer (RAFT) polymerization

Canadian Journal of Chemistry ◽

10.1139/v10-134 ◽

2011 ◽

Vol 89 (3) ◽

pp. 317-325 ◽

Cited By ~ 10

Author(s):

Binxin Li ◽

Daniel Majonis ◽

Peng Liu ◽

Mitchell A. Winnik

Keyword(s):

Chain Transfer ◽

Raft Polymerization ◽

Polymer Composition ◽

Cooh Group ◽

Agent Based ◽

Molecular Weights ◽

Reversible Addition ◽

Raft Agent ◽

End Use ◽

Naphthalimide Dye

We describe the synthesis of an end-functionalized copolymer of N-(2-hydroxypropyl)methacrylamide (HPMA) and N-hydroxysuccinimide methacrylate (NMS) by reversible addition–fragmentation chain transfer (RAFT) polymerization. To control the polymer composition, the faster reacting monomer (NMS) was added slowly to the reaction mixture beginning 30 min after initating the polymerization (ca. 16% HPMA conversion). One RAFT agent, based on azocyanopentanoic acid, introduced a –COOH group to the chain at one end. Use of a different RAFT agent containing a 4-amino-1,8-naphthalimide dye introduced a UV–vis absorbing and fluorescent group at this chain end. The polymers obtained had molecular weights of 30 000 and 20 000, respectively, and contained about 30 mol% NMS active ester groups.

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RAFT Graft Polymerization of 2-(Dimethylaminoethyl) Methacrylate onto Cellulose Fibre

Australian Journal of Chemistry ◽

10.1071/ch06247 ◽

2006 ◽

Vol 59 (10) ◽

pp. 737 ◽

Cited By ~ 24

Author(s):

Debashish Roy ◽

James T. Guthrie ◽

Sébastien Perrier

Keyword(s):

Graft Polymerization ◽

Chain Transfer ◽

Raft Polymerization ◽

Cellulose Fibre ◽

Monomer Conversion ◽

Living System ◽

Degree Of Polymerization ◽

Polymerization Time ◽

Grafted Polymer ◽

Reversible Addition

Poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) was grafted from cellulose by reversible addition–fragmentation chain transfer (RAFT) polymerization. The use of a free chain transfer agent in solution allowed for a better control over graft ratio, chain length of grafted polymer, monomer conversion, and homopolymer formation in solution. An increase in polymerization time or degree of polymerization led to an increase in graft ratio, as expected from a living system.

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Effect of silica nanoparticle loading and surface modification on the kinetics of RAFT polymerization

Journal of Polymer Engineering ◽

10.1515/polyeng.2011.601 ◽

2012 ◽

Vol 32 (1) ◽

Cited By ~ 18

Author(s):

Mehdi Salami-Kalajahi ◽

Vahid Haddadi-Asl ◽

Farid Behboodi-Sadabad ◽

Saeid Rahimi-Razin ◽

Hossein Roghani-Mamaqani

Keyword(s):

Molecular Weight ◽

Surface Modification ◽

Chain Transfer ◽

Raft Polymerization ◽

Silica Nanoparticle ◽

Maximum Level ◽

Silica Content ◽

Considerable Change ◽

Polymerization Rate ◽

Raft Agent

Abstract S-(thiobenzoyl)thioglycolic acid was used to synthesize poly(methyl methacrylate) via reversible addition-fragmentation chain transfer (RAFT) polymerization. To study the polymerization kinetics, in situ polymerization reactions were performed with different loading of nanoparticles. To investigate the effect of surface modification on the polymerization kinetics, similar reactions were performed with 3-methacryloxypropyldimethylchlorosilane-modified nanoparticles. Conversion, reaction rate, molecular weight and polydispersity index (PDI) were monitored during polymerization. According to results, pseudo-first order kinetics is achieved, but the rate constant of chain transfer reaction to the RAFT agent (Ctr) has a very small value. Adding nanoparticles causes no considerable change in the kinetic curves, while there is an optimum value for nanoparticles loading in which the polymerization rate reaches its maximum level. A similar trend is observed for molecular weight; however, increasing silica content results in an increase in PDI values. In comparison with pristine silica nanoparticles, the polymerization rate increases slowly in the case of modified particles. Also, molecular weight and PDI for free and graft chains are studied separately. The molecular weight of free chains increases with increasing nanoparticles loading up to 7 wt% and then decreases, while PDI values increase continually by adding nanoparticles. However, for graft chains, molecular weight and PDI values increase with increasing nanoparticle content.

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