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1.
Rapid ambient temperature living radical polymerization of methyl methacrylate and styrene utilizing sodium hypophosphite as reducing agent
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A facile, safe, and inexpensive reducing agent, sodium hypophosphite (NaH2PO2·H2O), has been successfully used to perform ambient temperature living radical polymerizations of methyl methacrylate (MMA) and styrene (St). The rapid radical polymerizations were readily obtained at 25°C, i.e., MMA reached a conversion of ca 90% after 2.5 h, and St reached a conversion of ca 80% after 40 h. The polymerizations of MMA and St exhibited excellent living/controlled nature, as evidenced by pseudo first‐order kinetics of polymerization, linear evolution of molecular weights with increasing monomer conversions, and narrow molecular weight distributions. The various experimental parameters—ligand, solvent, and molar ratio of NaH2PO2·H2O to CuSO4·5H2O—were varied to improve the control of polymerization, molecular weight, and molecular weight distribution. 1H NMR analyses and chain‐extension reactions confirm the high chain‐end functionality of the resultant poly(methyl methacrylate) and polystyrene. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42123. 相似文献
2.
Atom transfer radical polymerization (ATRP) of n‐butyl methacrylate (BMA) in water‐borne media, catalyzed and initiated by CuCl/4,4′‐di (5‐nonyl)‐2,2′‐bipyridine (dNbpy) and Ethyl 2‐bromopropinate (BrCH3CHCOOC2H5) was conducted. The influence of several factors, such as the amount of surfactant, catalyst, initiator and the reaction time, temperature on the stability of the latexes and the control of the polymerization was investigated. The nucleation mechanism of the latexes, thermodynamic data and activation parameters for the ATRP emulsion polymerization of BMA were also reported. POLYM. ENG. SCI. 45:297–302, 2005. © 2005 Society of Plastics Engineers. 相似文献
3.
Osamu Nakagawa Nobutaka Fujimoto Takafumi Nishiura Tatsuki Kitayama Koichi Hatada 《Polymer Bulletin》1992,29(5):579-586
Summary Highly syndiotactic diblock and triblock copolymers comprising lauryl methacrylate (LMA) and methyl methacrylate (MMA) with narrow molecular weight distributions were prepared by the living anionic polymerization with t-C4H9Li/(C2H5)3Al in toluene at low temperature. The block copolymers were soluble in acetone which is a non-solvent for poly(lauryl methacrylate) (PLMA). 1HNMR and vapor pressure osmometric analyses of the block copolymers indicated the aggregation of the copolymer in acetone through the interaction between PLMA blocks. Stereocomplex formation between the triblock copolymer and isotactic poly(methyl methacrylate) (PMMA) took place more effectively in solution than in the solid state. 相似文献
4.
Xiaohuan Zhang 《Polymer》2007,48(19):5507-5513
A series of well-defined graft copolymers with a polyallene-based backbone and poly(methyl methacrylate) side chains were synthesized by the combination of living coordination polymerization of 6-methyl-1,2-heptadien-4-ol and atom transfer radical polymerization of methyl methacrylate. We first prepared poly(alcohol) with polyallene repeating units via 6-methyl-1,2-heptadien-4-ol by living coordination polymerization initiated by [(η3-allyl)NiOCOCF3]2, followed by transforming the pendant hydroxyl groups into halogen-containing ATRP initiation groups. Next, grafting-from route was used for the synthesis of the well-defined graft copolymer with excellent solubility: poly(methyl methacrylate) was grafted to the backbone via ATRP of methyl methacrylate. This kind of graft copolymer is the first example of graft copolymer via allene derivative and methacrylic monomer. 相似文献
5.
In this study, we reported the synthesis of poly(methyl methacrylate) (PMMA) polymers via initiators for continuous activator regeneration atom transfer radical polymerization using CCl4 as initiator, FeCl3·6H2O/hexamethylene tetramine as catalyst complex, and 2,2′-azobis(isobutyronitrile) (AIBN) as reducing agent. The polymerization was conducted at 60 °C in the ionic liquid based microemulsion with hexadecyl trimethyl ammonium bromide (CTAB) as surfactant. Kinetics experimental results showed that the polymerization proceeded in a controlled/‘living’ process. The effects of the molar ratio of [CCl4]/[FeCl3·6H2O], the concentration of AIBN, temperature and the concentration of CTAB on the polymerization was investigated. The effect of CTAB concentration on the resulting PMMA particle size was also investigated. The obtained polymer was characterized by proton nuclear magnetic resonance and gel permeation chromatography. The living characteristics were demonstrated by chain extension experiment. 相似文献
6.
In this work, methyl methacrylate (MMA) was polymerized by initiator for continuous activator regeneration (ICAR) atom transfer radical polymerization (ATRP) method to obtain low molecular weight living polymers. The ATRP initiator was ethyl 2‐bromoisobutyrate, the catalyst ligand complex system was FeCl3·6H2O/succinic acid, and the conventional radical initiator 2,2′‐azobisisobutyronitrile was used as a thermal radical initiator. Polymers with controlled molecular weight were obtained with ppm level of Fe catalyst complex at 90°C in N,N‐dimethylformamide. The polymer was characterized by nuclear magnetic resonance (NMR). The molecular weight and molecular weight distribution of the obtained poly (methyl methacrylate) were measured by gel permeation chromatography method. The kinetics results indicated that ICAR ATRP of MMA was a “living”/controlled polymerization, corresponding to a linear increase of molecular weights with the increasing of monomer conversion and a relatively narrow polydispersities index. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
7.
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 相似文献
8.
Lanthanide(II) complexes supported by amido ligands, [(C6H5)(Me3Si)N]2Ln(DME)2 [Ln = Sm ( 1 ) or Yb ( 2 ); DME = 1,2‐dimethoxyethane] and [(C6H3? iPr2‐2,6)(Me3Si)N]2Ln(THF)2 [Ln = Sm ( 3 ) or Yb ( 4 ); THF = tetrahydrofuran], were found to initiate the polymerization of methyl methacrylate (MMA) as efficient single‐component initiators (in toluene for 3 and 4 and in toluene with a small amount of THF for 1 and 2 ) to produce syndiotactic polymers. The catalytic behavior was highly dependent on both the amido ligand and the polymerization temperature. Initiators 3 and 4 initiated MMA polymerization over a wide range of temperatures (20°C to ?40°C), whereas the polymerization with 1 and 2 proceeded smoothly only at low temperatures (≤0°C). The kinetic behavior and some features of the polymerizations of MMA initiated by 3 and 4 were studied at ?40°C. The polymerization rate was first‐order with the monomer concentration. The molar masses of the polymers increased linearly with the increase in the polymer yields, whereas the molar mass distributions remained narrow and unchanged throughout the polymerization; this indicated that these systems had living character. A polymerization mechanism initiated by bimetallic bisenolate formed in situ was proposed. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
9.
Yun-hai Yu Xiao-hui Liu Di Jia Bo-wen Cheng Fei-jun Zhang Peng Chen Shan Xie 《Polymer》2013,54(1):148-154
A universal nitrogen based ligand, tris[2-(dimethylamino) ethyl] amine (Me6TREN), was firstly employed as both reducing agent and ligand for atom transfer radical polymerization with activators regenerated by electron transfer (ARGET ATRP) of methyl methacrylate (MMA) in bulk and solution, using CuBr2 as the catalyst and 2-bromoisobutyrate as the initiator. Remarkably high activity catalytic system (CuBr2/Me6TREN) enabled the ambient temperature polymerization and thus biradical termination reactions were low. The polymerization exhibited typical living radical polymerization features, including pseudo first-order kinetics of polymerization, linear increase in the molecular weight versus monomer conversion, and low polydispersity index values. Moreover, effects of solvent and reaction temperature on the polymerization were investigated in detail. The rate of polymerization increased with reaction temperature and the apparent activation energy of the polymerization was calculated to be 51.11 kJ/mol. Gel permeation chromatography and 1H NMR analyses as well as chain extension experiment confirmed the living chain-end functionality. 相似文献
10.
In studying the characteristics of graft polymerization of glycidyl methacrylate (GMA) on the boundary of the solid (polyvinyl alcohol (PVA) fibre) and liquid phases, it was shown that the concentration order of the reaction rate in the monomer and H2O2 was similar to the order for classic radical polymerization processes. The specific effect of the thermodynamics on the kinetics of the process was established in a relatively narrow temperature region (50–80°C), manifested by significantly different activation energies.Translated from Khimicheskie Volokna, No. 5, pp. 51–54, September–October, 1995. 相似文献
11.
Influence of chemical functionalization of carbon nanotubes on their dispersibility in alkyl methacrylate polymer matrix
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Nanocomposites based on poly(methyl methacrylate) (PMMA) and poly(methyl methacrylate‐co‐octadecyl methacrylate) (M/O) matrices and four different types of multiwall carbon nanotubes: pristine, oxidized (MWCNT–COOH), methyl ester (MWCNT–COOCH3), and dodecyl ester (MWCNT–COOC12H25) functionalized, were prepared in situ by radical (co)polymerization. The effectiveness of preparation of nanocomposites regarding dispersion and distribution of various MWCNT in polymer matrices was sized by Scanning electron microscopy. In case of PMMA matrix, the best dispersion and distribution were accomplished for MWCNT–COOCH3 due to their chemical resemblance with polymer matrix. After the introduction of 10 mol % of octadecyl methacrylate in polymer matrix a fairly good dispersion and distribution of MWCNT–COOCH3 were retained. The addition of 1 wt % of MWCNTs caused a significant reduction in the degree of polymerization of the PMMA matrix. But at the same time, the present MWCNTs increased storage modulus of PMMA nanocomposites except for dodecyl ester functionalized MWCNT. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46113. 相似文献
12.
Synthesis of fluorescent poly(methyl methacrylate) via AGET ATRP 总被引:1,自引:0,他引:1
Polymerization of methyl methacrylate (MMA) was successfully carried out via activator generated by electron transfer for
atom transfer radical polymerization technique with naphthalene-1,5-diyl-bis (2-bromo-2-methylpropanoate) as an initiator,
CuCl2/bpy complex as a catalyst and tin(II) 2-ethylhexanoate (Sn(EH)2) as a reducing agent in anisole. The polymerization showed typical features of “living”/controlled radical polymerization
such as a linear increase of the molecular weights of the polymers with monomer conversion and relatively narrow polydispersities
throughout the polymerization process. The resultant fluorescent poly(methyl methacrylate) was characterized by nuclear magnetic
resonance spectroscopy, infrared absorption spectroscopy, ultraviolet absorption spectrophotometry and fluorescence spectrophotometry. 相似文献
13.
The reverse atom transfer radical polymerization of methyl methacrylate was investigated in different solvents: xylene, N,N‐dimethylformamide, and pyridine. The polymerizations were uncontrolled, using 2,2′‐bipyridine as a ligand in xylene and pyridine because the catalyst (CuBr2/2,2′‐bipyridine complex) had poor solubility in the xylene system. In the pyridine system, the solubility of the catalyst increased, but the solvent could complex with CuBr2, which influenced the control of the polymerization. In the N,N‐dimethylformamide system, the catalyst could be dissolved in the solvent completely, but the ? N(CH3)2 group in N,N‐dimethylformamide could also complex with CuBr2, so the polymerization could not be well controlled. The ligand of 4,4′‐di(5‐nonyl)‐2,2′‐bipyridine was also investigated in xylene; the introduction of the ? CH(C4H9)2 group enabled the CuBr2/4,4′‐di(5‐nonyl)‐2,2′‐bipyridine complex to easily dissolve in xylene, and the polymerizations were well controlled. The number‐average molecular weight increased linearly with the monomer conversion from 4280 to 14,700. During the whole polymerization, the polydispersities were quite low (1.07–1.10). © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007 相似文献
14.
Vinyl polymerization initiated by a copper complex immobilized on a novel polymer and characterization has been studied. Monomer, 4‐aldehyde‐3‐hydroxy phenyl acrylate (Ahpa), and its homopolymer, poly(4‐aldehyde‐3‐hydroxy phenyl acrylate) (PAhpa), were synthesized and characterized using IR, elemental analysis, 1H NMR, TOF MS, etc. The side chain of the polymer can further coordinate with transition metal ions. Its polymeric Cu(II) complex in Na2SO3 system is proved to be another useful catalyst in polymerization of methyl methacrylate (MMA) at room temperature. The obtained poly(methyl methacrylate) (PMMA) is similar to those determined by conventional free radical polymerization at the same conditions. Moreover, the catalytic mechanism studied was a “Coordination Hydrogen‐Transfer” process, which is different from that of CuCl2/Na2SO3 system, but analogous with that of PVAm‐Cu(II)/Na2SO3 (PVAm = polyvinylamine) system, was speculated and testified. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1285–1290, 2007 相似文献
15.
Well-defined homopolymer of 2,3,5,6-tetrafluorophenyl methacrylate (TFPM) was successfully synthesized via atom transfer radical polymerization (ATRP) technique. Controlled polymerization was achieved with the addition of CuBr2 as deactivator, which decreased the reaction rate and minimized the premature termination. The controlled/“living” polymerization behavior was supported by kinetic studies and the full chain extension for block copolymerization with 2-(dimethylamino) ethyl methacrylate (DMAEMA). Poly(TFPM) is an useful precursor for poly(methacrylamides) library syntheses. The active ester groups reacted with a variety of amines to produce a range of well-defined poly(methacrylamides), some of which would have been difficult to obtain by direct polymerizations of the methacrylamide monomers. Complete conversion to poly(methacrylamide) was achieved with unhindered primary amines. Substitution reactions with aromatic amines such as aniline did not occur under normal reaction conditions. 相似文献
16.
Vishal Anand Seema Agarwal Andreas Greiner Veena Choudhary 《Polymer International》2005,54(5):823-828
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 (Mn = 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 相似文献
17.
Iron‐mediated activators generated by electron transfer for atom‐transfer radical polymerization of methyl methacrylate using ionic liquid as ligand and Fe(0) wire as reducing agent
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Liangjiu Bai Suqi Huang Wenxiang Wang Hui Xu Hou Chen Yuzhong Niu Minghua Wang 《Polymer International》2015,64(12):1754-1761
1‐Butyl‐3‐methylimidazolium hexafluorophosphate (BMIMPF6) as a typical ionic liquid (IL) effectively acted as ligand for the control of iron‐mediated activators generated by electron transfer for atom‐transfer radical polymerization of methyl methacrylate (MMA) in the presence of a limited amount of oxygen, using FeCl3.6H2O as the catalyst and Fe(0) wire as the reducing agent. The polymers obtained with BMIMPF6 had controlled molecular weights and low Mw/Mn values (<1.40). Moreover, a well‐defined final product PMMA without additional processing was easily obtained and the reducing agent (iron wire) could be recycled and reused effectively just by washing three times with solvents. 相似文献
18.
Silica (SiO2)‐crosslinked polystyrene (PS) particles possessing photofunctional N,N‐diethyldithiocarbamate (DC) groups on their surface were prepared by the free‐radical emulsion copolymerization of a mixture of SiO2 (diameter = 20 nm), styrene, divinyl benzene, 4‐vinylbenzyl N,N‐diethyldithiocarbamate (VBDC), and 2‐hydroxyethyl methacrylate with a radical initiator under UV irradiation. In this copolymerization, the inimer VBDC had the formation of a hyperbranched structure by a living radical mechanism. The particle sizes of such core–shell structures [number‐average particle diameter (Dn) = 35–40 nm] were controlled by the variation of the feed amounts of the monomers and surfactant, or emulsion system. The size distributions were relatively narrow (weight‐average particle diameter/Dn ≈ 1.05). These particles had DC groups on their surface. Subsequently, poly(methyl methacrylate) brush encapsulated SiO2 particles were synthesized by the grafting from a photoinduced atom transfer radical polymerization approach of methyl methacrylate initiated by SiO2‐crosslinked PS particles as a macroinitiator. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
19.
The dilute solution properties of a cationic polyelectrolyte, poly(dimethyl sulfate quaternized dimethylaminoethyl methacrylate) [poly(DMAEM · C2H6SO4)], are studied by measurements of intrinsic viscosity, degree of binding, and flocculation application. The intrinsic viscosity of this polyelectrolyte is related to the type and concentration of added salt. The intrinsic viscosity behavior for cationic polyelectrolyte resulting from the electrostatic repulsive force of the polymer chain is contrasted with polyampholyte. The polyelectrolyte in the presence of KCl has a lower degree of binding, indicating that the proton ion (H+) is relatively difficult to bind to the CH3SO4? at the polymer end. The polymerization of DMAEM · C2H6SO4 in 0.5M KCl aqueous solution proceeded more easily than that of DMAEM · C2H6SO4 in pure water. The polymerization rate of DMAEM · C2H6SO4 is found to pass through an extreme value as a function of pH. Optimum flocculation, corresponding to the complete removal of turbidity in the supernatant, is achieved. Beyond the optimum flocculation, high polymer dosages redisperse the bentonite suspensions. 相似文献
20.
C. P. Reghunadhan Nair 《Polymer International》1998,46(4):313-319
5-Bromopenta-1,3-diene (BPD) was examined as an addition-fragmentation chain transfer agent (AFCTA) in the free radical polymerization of methyl methacrylate (MMA). Studies of the kinetics of polymerization in the presence of this compound showed it to be a very effective chain transfer agent and that retardation was not significant, implying efficient reinitiation by the expelled Br radical. Analysis of the resulting polymers showed that the intermediate radical formed by the addition of the propagating radical to the C1 carbon of BPD underwent exclusive fragmentation. However, addition on the C4 carbon, with a relative probability of 0·6, led to its copolymerization with MMA. Kinetic studies showed BPD to be a better chain-end functionalization agent than its 5-t-butyl thio derivative for deriving pentadiene-functional macromonomer. © 1998 SCI. 相似文献