Reverse ATRP of acrylonitrile with diethyl 2,3-dicyano-2,3-diphenyl succinate/FeCl3/iminodiacetic acid

The reverse atom transfer radical polymerization (RATRP) technique using FeCl₃/iminodiacetic acid (IMA) complex as a catalyst was applied to the living radical polymerization of acrylonitrile (AN). A hexa-substituted ethane thermal initiator, diethyl 2,3-dicyano-2,3-diphenylsuccinate (DCDPS), was firstly used as the initiator in this iron-based RATRP system. The polymerization in N,N-dimethylformamide not only shows the best control of molecular weight and its distribution but also provides rather rapid reaction rate with the ratio of [AN]:[DCDPS]:[FeCl₃]:[IMA] at 500:1:2:4. The rate of polymerization increases with increasing the polymerization temperature and the apparent activation energy was calculated to be 49.9 kJ mol⁻¹. The polymers obtained were end-functionalized by chlorine atom, and they were used as macroinitiators to proceed the chain extension polymerization in the presence of FeCl₂/IMA catalyst system via a conventional ATRP process. The resultant polyacrylonitrile fibers were obtained with the fineness at 1.16 dtex and the tenacity at 6.01cN dtex⁻¹.     

An iron‐based reverse ATRP process for the living radical polymerization of acrylonitrile

A hexa‐substituted ethane thermal iniferter, diethyl‐2,3‐dicyano‐2,3‐di(p‐tolyl) succinate (DCDTS), was firstly used as the initiator in the reverse atom transfer radical polymerization (RATRP) of acrylonitrile. FeCl₃ coordinated by isophthalic acid (IA) was used as the catalyst in this system. The polymerization in N,N‐dimethylformamide not only shows the best control of molecular weight and its distribution but also provides rather rapid reaction rate with the ratio of [AN] : [DCDTS] : [FeCl₃] : [IA] at 500 : 1 : 2 : 4. The polymers obtained were end‐functionalized by chlorine atom, and they were used as macroinitiators to proceed the chain extension polymerization in the presence of FeCl₂/IA catalyst system via a conventional ATRP process and polyacrylonitrile obtained was with M_n = 39,260, PDI = 1.25. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Synthesis of polyacrylonitrile via reverse ATRP initiated by 1,1,2,2‐tetraphenyl‐1,2‐ethanediol/CuCl2/2,2′‐bipyridine

The reverse atom‐transfer radical polymerization (RATRP) technique using CuCl₂/2,2′‐bipyridine (bipy) complex as a catalyst was applied to the living‐radical polymerization of acrylonitrile (AN). 1,1,2,2‐Tetraphenyl‐1,2‐ethanediol (TPED) was first used as the initiator in this copper‐based RATRP initiation system. A CuCl₂ to bipy ratio of 0.5 not only gives the best control of molecular weight and its distribution, but also provides rather rapid reaction rate. The rate of polymerization increases with increasing the polymerization temperature, and the apparent activation energy was calculated to be 53.2 kJ mol^?1. Because the polymers obtained were end‐functionalized by chlorine atoms, they were used as macroinitiators to proceed the chain extension polymerization in the presence of CuCl/bipy catalyst system via a conventional ATRP process. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3529–3533, 2007     

Synthesis of well‐defined polystyrene by radical polymerization using 1,1,2,2‐tetraphenyl‐1,2‐ethanediol/feCl3/PPh3 initiation system

Well‐defined polystyrenes with an α‐hydrogen atom and an ω‐chlorine atom end groups and narrow polydispersity (M_n = 2500–4200, M_w/M_n = 1.29–1.48) have been synthesized by a free radical polymerization process using a 1,1,2,2‐tetraphenyl‐1,2‐ethanediol (TPED)/FeCl₃/PPh₃ initiation system. The end groups were monitored by ¹H nuclear magnetic resonance spectroscopy. When the polymerization of styrenes in bulk carried out at 120°C and the ratio of [St]₀ : [TPED]₀ : [FeCl₃]₀ : [PPh₃]₀ was 200 : 1 : 4 : 12, the polymerization exhibited some living/controlled radical polymerization characteristics. The polymerization mechanism was proposed proceeding via a reverse atom transfer radical polymerization (ATRP). Because the polymers obtained were end‐functionalized by chlorine atoms, they were used as macroinitiators to proceed chain extension polymerization in the presence of CuCl/2,2′‐bipyridine catalyst system via a conventional ATRP process. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 1607–1613, 2000     

Synthesis of polyacrylonitrile via reverse atom transfer radical polymerization initiated by 1,1,2,2‐tetraphenyl‐1,2‐ethanediol/FeCl3/triphenylphosphine

FeCl₃ coordinated by triphenylphosphine was first used as the catalyst in the 1,1,2,2‐tetraphenyl‐1,2‐ethanediol‐initiated reverse atom transfer radical polymerization of acrylonitrile. A FeCl₃/triphenylphosphine ratio of 0.5 not only gave the best control of the molecular weight and its distribution but also provided a rather rapid reaction rate. The rate of polymerization increased with increasing polymerization temperature, and the apparent activation energy was calculated to be 62.4 kJ/mol. When FeCl₃ was replaced with CuCl₂, the reverse atom transfer radical polymerization of acrylonitrile did not show prominent living characteristics. To demonstrate the active nature of the polymer chain end, the polymers were used as macroinitiators to advance the chain‐extension polymerization in the presence of a CuCl/2,2′‐bipyridine catalyst system via a conventional atom transfer radical polymerization process. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 4041–4045, 2007     

‘Living’ radical polymerization of styrene with AIBN/FeCl3/PPh3 initiating system via a reverse atom transfer radical polymerization process

Well‐defined polystyrenes with an α‐C(CH₃)₂(CN) and an ω‐chlorine atom end‐groups, and narrow polydispersity (M_n = 3000–4000 g mol⁻¹, M_w/M_n = 1.3–1.4) have been synthesized by a radical polymerization process using 2,2′‐azobisisobutyronitrile(AIBN)/FeCl₃/PPh₃ initiation system. When the ratio of [St]₀:[AIBN]₀:[FeCl₃]₀:[PPh₃]₀ is 200:1:4:12 at 110 °C, the radical polymerization is ‘living’, but the molecular weight of the polymers is not well‐controlled. The polymerization mechanism belongs to a reverse atom transfer radical polymerization (ATRP). Because the polymer obtained is end‐functionalized by a chlorine atom, it can then be used as a macroinitiator to perform a chain extension polymerization in the presence of CuCl/2,2′‐bipyridine catalyst system via a conventional ATRP process. The presence of a chlorine atom as an end‐group was determined by ¹H NMR spectroscopy. © 2000 Society of Chemical Industry     

Photo‐Induced atom transfer radical polymerization with nanosized α‐Fe2O3 as photoinitiator

Photo‐induced atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) was achieved in poly(ethylene glycol)‐400 with nanosized α‐Fe₂O₃ as photoinitiator. Well‐defined poly(methyl methacrylate) (PMMA) was synthesized in conjunction with ethyl 2‐bromoisobutyrate (EBiB) as ATRP initiator and FeCl₃·6H₂O/Triphenylphosphine (PPh₃) as complex catalyst. The photo‐induced polymerization of MMA proceeded in a controlled/living fashion. The polymerization followed first‐order kinetics. The obtained PMMA had moderately controlled number‐average molecular weights in accordance with the theoretical number‐average molecular weights, as well as narrow molecular weight distributions (M_w/M_n). In addition, the polymerization could be well controlled by periodic light‐on–off processes. The resulting PMMA was characterized by ¹H nuclear magnetic resonance and gel permeation chromatography. The brominated PMMA was used further as macroinitiator in the chain‐extension with MMA to verify the living nature of photo‐induced ATRP of MMA. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42389.     

Reverse atom‐transfer radical polymerization of acrylonitrile catalyzed by FeCl3/iminodiacetic acid

FeCl₃ coordinated by iminodiacetic acid (IMA) was Changed used for the first time as the catalyst in azobisisobutyronitrile‐initiated reverse atom‐transfer radical polymerization (ATRP) of acrylonitrile (AN). An FeCl₃ to IMA ratio of 1:2 not only gave the best control of molecular weight and its distribution but also provided a rather rapid reaction rate. The effects of solvents on the polymerization of AN were also investigated. The rate of the polymerization in N,N‐dimethylformamide (DMF) was faster than in propylene carbonate or toluene. The molecular weight of polyacrylonitrile agreed reasonably well with the theoretical molecular weight in DMF. The rate of polymerization increased with increasing polymerization temperature and the apparent activation energy was calculated to be 54.8 kJ mol⁻¹. The reverse ATRP of AN did not show obvious living characteristics with CuCl₂ instead of FeCl₃. Copyright © 2005 Society of Chemical Industry     

The reaction mechanism of diethyl‐2,3‐dicyano‐2,3‐di(p,m‐dimethoxylphenyl) succinate with styrene

The radical polymerization of styrene (ST) can be initiated by diethyl‐2,3‐dicyano‐2,3‐di(dimethoxyphenyl) succinate (ECPS). The reaction mechanism has been studied by means of UV, H¹‐NMR, product analysis, gel permeation chromatography, electronic spin resonance (ESR), and the conversion of monomer via time. These experimental results indicate that ECPS probably takes the place of complex with ST, and the complex interaction between ECPS and ST can take advantage of the dissociation of the C C bond. The complex interaction and thermal effect are the important factors causing the dissociation of C C bond. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 1140–1145, 1999     

Fe‐mediated ARGET atom transfer radical polymerization of methyl methacrylate in ionic liquid‐based microemulsion

Poly(methyl methacrylate) (PMMA) was synthesized by activator regenerated by electron transfer (ARGET) atom transfer radical polymerization (ATRP) of MMA in ionic liquid‐based microemulsion with polyoxyethylene sorbitan monooleate (Tween 80) as surfactant. The polymerization was carried out at 25°C with CCl₄ as initiator, FeCl₃·6H₂O/N,N,N′,N′‐tetramethyl‐1,2‐ethanediamine (TMEDA) as catalyst complex in the presence of reducing agent ascorbic acid (VC). The polymerization kinetics showed the feature of controlled/″living″ process as evidenced by a linear first‐order plot. The well‐controlled polymers were obtained with narrow polydispersity indices and the ionic liquid‐based microemulsions were transparent with a particle size less than 30 nm. The obtained polymer was characterized by ¹H NMR and gel permeation chromatography. The chain extension was successfully achieved by the obtained PMMA macroinitiator/FeCl₃·6H₂O/TMEDA/VC initiator system based on ARGET ATRP method. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Synthesis and characterization of poly(p‐phenylene)‐graft‐poly(ε‐caprolactone) copolymers by combined ring‐opening polymerization and cross‐coupling processes

2,5‐Dibromo‐1,4‐(dihydroxymethyl)benzene was used as initiator in ring‐opening polymerization of ε‐caprolactone in the presence of stannous octoate (Sn(Oct)₂) catalyst. The resulting poly(ε‐caprolactone) (PCL) macromonomer, with a central 2,5‐dibromo‐1,4‐diphenylene group, was used in combination with 1,4‐dibromo‐2,5‐dimethylbenzene for a Suzuki coupling in the presence of Pd(PPh₃)₄ as catalyst or using the system NiCl₂/bpy/PPh₃/Zn for a Yamamoto‐type polymerization. The poly(p‐phenylenes) (PPP) obtained, with PCL side chains, have solubility properties similar to those of the starting macromonomer, ie soluble in common organic solvents at room temperature. The new polymers were characterized by ¹H and ¹³C NMR and UV spectroscopy and also by GPC measurements. The thermal behaviour of the precursor PCL macromonomer and the final poly(p‐phenylene)‐graft‐poly(ε‐caprolactone) copolymers were investigated by thermogravimetric analysis and differential scanning calorimetry analyses and compared. Copyright © 2004 Society of Chemical Industry     

RATRP of MMA in AIBN/FeC1<Subscript>3</Subscript>/PPh<Subscript>3</Subscript> initiation system under microwave irradiation

Summary Reverse atom transfer radical polymerization (RATRP) of methyl methacrylate (MMA) under microwave irradiation (MI), using azobisisobutyronitrile (AIBN) /FeC1₃/triphenylphosphine (PPh₃) as the initiating system, was successfully carried out in N, N-dimethylformamide (DMF) at 69°C. Plots of In ([MI₀/[M]) vs. time and molecular weight evolution vs. conversion showed a linear dependence. A polymer for reaching 82% conversion, with molecular weight (M_n) 34,000 and polydispersity index (PDI) 1.37, was obtained under MI (90U') with the ratio of [MMA]₀/[AIBN]₀/[FeCl₃]₀/[PPh₃]₀ = 1600/2/4/8 in only 60 min; while 840 min was required under conventional heating (CH) process for reaching 82 % conversion (M_n = 48,000 and PDI = 1.31) at identical polymerization conditions, indicating a significant enhancement of the polymerization rates and apparent initiator efficiencies under MI. Received: 2 September 2002/Revised version: 3 October 2002/Accepted: 10 December 2002 Correspondence to Xiulin Zhu     

Synthesis of methyl methacrylate and N‐aryl itaconimide block copolymers via atom‐transfer radical polymerization

The paper describes the synthesis of block copolymers of methyl methacrylate (MMA) and N‐aryl itaconimides using atom‐transfer radical polymerization (ATRP) via a poly(methyl methacrylate)–Cl/CuBr/bipyridine initiating system or a reverse ATRP AIBN/FeCl₃·6H₂O/PPh₃ initiating system. Poly(methyl methacrylate) (PMMA) macroinitiator, ie with a chlorine chain‐end (PMMA‐Cl), having a predetermined molecular weight (M_n = 1.27 × 10⁴ g mol^?1) and narrow polydispersity index (PDI = 1.29) was prepared using AIBN/FeCl₃·6H₂O/PPh₃, which was then used to polymerize N‐aryl itaconimides. Increase in molecular weight with little effect on polydispersity was observed on polymerization of N‐aryl itaconimides using the PMMA‐Cl/CuBr/Bpy initiating system. Only oligomeric blocks of N‐aryl itaconimides could be incorporated in the PMMA backbone. High molecular weight copolymer with a narrow PDI (1.43) could be prepared using tosyl chloride (TsCl) as an initiator and CuBr/bipyridine as catalyst when a mixture of MMA and N‐(p‐chlorophenyl) itaconimide in the molar ratio of 0.83:0.17 was used. Thermal characterization was performed using differential scanning calorimetry (DSC) and dynamic thermogravimetry. DSC traces of the block copolymers showed two shifts in base‐line in some of the block copolymers; the first transition corresponds to the glass transition temperature of PMMA and second transition corresponds to the glass transition temperature of poly(N‐aryl itaconimides). A copolymer obtained by taking a mixture of monomers ie MMA:N‐(p‐chlorophenyl) itaconimide in the molar ratio of 0.83:0.17 showed a single glass transition temperature. Copyright © 2005 Society of Chemical Industry     

Synthesis of poly(octadecyl acrylate‐b‐styrene‐b‐octadecyl acrylate) triblock copolymer by atom transfer radical polymerization

The synthesis of triblock copolymer poly(octadecyl acrylate‐b‐styrene‐b‐octadecyl acrylate), using atom transfer radical polymerization (ATRP), is reported. The copolymers were prepared in two steps. First, polystyrene was synthesized by ATRP using α,α′‐dichloro‐p‐xylene/CuBr/bpy as the initiating system; Second, polystyrene was further used as macroinitiator for the ATRP of octadecyl acrylate to prepare ABA triblock copolymers in the presence of FeCl₂·4H₂O/PPh₃ in toluene. Polymers with controlled molecular weight (M_n = 17,000–23,400) and low polydispersity index value (1.33–1.44) were obtained. The relationship between molecular weight versus conversion showed a straight line. The effect of reaction temperature on polymerization was also investigated, showing a faster polymerization rate under higher temperature. The copolymers were characterized by FTIR, ¹H‐NMR, DSC, and GPC and the crystallization behavior of the copolymers was also studied. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1539–1545, 2004     

Polymerization of methyl methacrylate with a thermal iniferter: Diethyl 2,3‐dicyano‐2,3‐di(p‐tolyl)succinate

A hexa‐substituted ethane type compound, diethyl‐2,3‐dicyano‐2,3‐di(p‐tolyl)succinate (DCDTS), was successfully synthesized and used for initiation of methyl methacrylate (MMA) polymerization. The reaction demonstrated the characteristics of a “living” polymerization; i.e., both the yield and the molecular weight of the resulting polymers increased linearly with increasing reaction time, the molecular‐weight distribution of PMMA obtained was ～1.60 and almost unaffected by the conversion, and the resultant polymer can be chain extended by adding fresh MMA. End group analysis of the resultant PMMA confirmed that DCDTS behaves as a thermal iniferter for MMA polymerization. A block copolymer was prepared from the resultant PMMA, which contains a hexa‐substituted C? C bond functional end group. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2566–2572, 2001     

An investigation into the degree and rate of polymerization of poly(methyl methacrylate) in the ionic liquid 1‐butyl‐3‐methylimidazolium hexafluorophosphate

Room‐temperature ionic liquids (ILs), including 1‐butyl‐3‐methylimidazolium hexafluorophosphate, [bmim⁺][PF₆^?], were investigated as replacements for volatile organic compounds in the free‐radical solution polymerization of poly(methyl methacrylate) (PMMA). The latter was synthesized in benzene and [bmim⁺][PF₆^?] at 70 °C via a free‐radical process and the degree and rate of polymerization were compared based on the solvent used. The degree of polymerization was found to be five times higher in [bmim⁺][PF₆^?] than in benzene, while the rate of reaction was approximately four times faster in [bmim⁺][PF₆^?]. The results indicate the potential for using ILs to produce high‐molecular‐weight polymers and block structures based on the increased free‐radical stability in ILs. Copyright © 2004 Society of Chemical Industry     

Reverse atom transfer radical polymerization of acrylonitrile

FeCl₃ coordinated by succinic acid was used as the catalyst for the first time in azobisisobutyronitrile‐initiated reverse atom transfer radical polymerization of acrylonitrile (AN). N,N‐dimethylformamide (DMF) was used as a solvent to improve the solubility of the ligand. A FeCl₃ to succinic acid ratio of 0.5 not only gives the best control of molecular weight and its distribution but also provides rather rapid reaction rate. Effects of different solvents on polymerization of AN were also investigated. The rate of the polymerization in DMF is faster than that in propylene carbonate and toluene. The molecular weight of polyacrylonitrile agrees reasonably well with the theoretical molecular weight in DMF. The rate of polymerization increases with increasing the polymerization temperature, and the apparent activation energy was calculated to be 64.8 kJ mol^?1. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 32–36, 2006     

ATRP of acrylonitrile catalyzed by FeCl2/succinic acid under microwave irradiation

A single‐pot atom‐transfer radical polymerization (ATRP) under microwave irradiation was first used to successfully synthesize polyacrylonitrile. This was achieved by using FeCl₂/succinic acid as the catalyst and 2‐chloropropionitrile as the initiator. Using the same experimental conditions, the apparent rate constant under microwave irradiation was found to be higher than that under conventional heating. The FeCl₂/succinic acid ratio of 1 : 2 not only gives the best control of molecular weight and its distribution but also provides rather rapid reaction rate. When FeCl₂ was replaced with CuCl, ATRP of AN does not show an obvious living characteristics. To demonstrate the active nature of the polymer chain end, the polymers were used as macroinitiators to proceed the chain‐extension polymerization. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1598–1601, 2006     

Characterization and anticorrosive properties of poly(2,3‐dimethylaniline)/Na+‐montmorillonite composite prepared by emulsion polymerization

Composites of Poly(2,3‐dimethylaniline) and inorganic Na⁺‐montmorillonite clay were synthesized by emulsion polymerization. The as‐synthesized composites (PDMA) were characterized by Fourier Transform Infrared Spectroscopy, X‐ray diffraction, and scanning electron microscopy. The protective performance against corrosion of the samples was evaluated by Tafel and electrochemical impedance spectroscopy measurements. The results showed that the composite containing 5 wt. % of clay loading (PDMA‐5%) displayed a better anticorrosive performance than other samples. The Epoxy(E) blend with PDMA‐5% (EPM5) coating was founded to have a higher corrosion potential and a lower current density than that of Epoxy blend P(2,3‐DMA) (EP) coating. The impedance value of EPM5 coating was about 6.68×10⁶Ω·cm² in 5 wt. % NaCl solution even after 288 h, compared to EP (4.26×10⁵Ω·cm²) coating, which went to show that the corrosion inhibition of P(2,3‐DMA) could be effectively enhanced by incorporating MMT into the P(2,3‐DMA) matrix. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4528–4533, 2013     

Fe‐mediated ICAR ATRP of styrene and acrylonitrile in polyethylene glycol

In this contribution, random copolymers of p(styrene‐co‐acrylonitrile) via initiators for continuous activator regeneration (ICAR) in atom transfer radical polymerization (ATRP) (ICAR ATRP) of styrene and acrylonitrile (SAN) were synthesized at 90°C in low molecular weight polyethylene glycol (PEG‐400) using CCl₄ as initiator, FeCl₃·6H₂O as catalyst, succinic acid as ligand and thermal radical initiator azobisisobutyronitrile (AIBN) as thermal free radical initiator. In this system, well‐defined copolymer of SAN was achieved. The kinetics results showed that the copolymerization rate obeyed first‐order kinetics model with respect to the monomer concentration, and a linear increase of the molecular weights with the increasing of monomer conversion with narrow molecular weight distribution was observed in the range of 1.1–1.5. The conversion decreased with increasing the amount of FeCl₃·6H₂O and increased with increasing the molar ratio of [St]₀/[AN]₀/[CCl₄]₀ and temperature. AIBN has a profound effect on the polymerization. The activation energy was 55.67 kJ mol^?1. The living character of copolymerization was confirmed by chain extension experiment. The resultant random copolymer was characterized by ¹H‐NMR and GPC. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40135.