Polymerization of methyl methacrylate with cupric laurate–benzoin system as initiator

The polymerization of methyl methacrylate initiated by cupric laurate in combination with benzoin has been investigated in carbon tetrachloride medium at 60°C. The rate of polymerization was found to be proportional to the square root of both cupric ion and benzoin concentrations, and to the 1.5th power of the monomer concentration. Spectral studies indicated that there is a complex formation between cupric ion and the monomer methyl methacrylate. A reaction scheme, based on initial formation of the complex and its subsequent reaction with benzoin to produce the free radicals responsible for initiation has been postulated to explain the observed results.     

Synthesis of poly(methyl methacrylate) via ARGET ATRP and study of the effect of solvents and temperatures on its polymerization kinetics

This investigation reports the synthesis of poly(methyl methacrylate) via activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP) and studies the effect of solvents and temperature on its polymerization kinetics. ARGET ATRP of methyl methacrylate (MMA) was carried out in different solvents and at different temperatures using CuBr₂ as catalyst in combination with N,N,N′,N″,N″‐pentamethyldiethylenetriamine as a ligand. Methyl 2‐chloro propionate was used as ATRP initiator and ascorbic acid was used as a reducing agent in the ARGET ATRP of MMA. The conversion was measured gravimetrically. The semilogarithmic plot of monomer conversion versus time was found to be linear, indicating that the polymerization follows first‐order kinetics. The linear polymerization kinetic plot also indicates the controlled nature of the polymerization. N,N‐Dimethylformamide (DMF), tetrahydrofuran (THF), toluene, and methyl ethyl ketone were used as solvents to study the effect on the polymerization kinetics. The effect of temperature on the kinetics of the polymerization was also studied at various temperatures. It has been observed that polymerization followed first‐order kinetics in every case. The rate of polymerization was found to be highest (k_app = 6.94 × 10⁻³ min⁻¹) at a fixed temperature when DMF was used as solvent. Activation energies for ARGET ATRP of MMA were also calculated using the Arrhenius equation.     

Homogeneous Solution Reverse Atom Transfer Radical Polymerization of Methyl Methacrylate

A homogeneous reverse atom transfer radical polymerization (RATRP) of methyl methacrylate (MMA) was successfully carried out in N, N-dimethylformamide(DMF) (25%, v/v) at 69°C, using an initiating system azobisisobutyronitrile (AIBN)/CuBr₂/N, N, N′, N″, N″-pentamethyldiethylenetriamine (PMDETA). The kinetics of homogeneous solution polymerizations showed linear first-order rate plots, indicating a constant number of growing species throughout the polymerization as well as a negligible contribution of termination or transfer reactions; a linear increase of the number-average molecular weight with conversion, and relatively low polydispersities, but low initiator efficiency. The dependence of the rate of polymerization on the concentrations of initiator, catalyst, ligand and temperature were presented.     

Effect of reaction conditions on the homo and copolymerizations of N-(1-naphthyl)acrylamide

In this work, we studied the influence of time reaction and initiator amount on N-(1-naphthyl)acrylamide (NAM) polymerization, in dioxane and DMF. The same was done with three copolymers with methyl methacrylate (MMA). We found that NAM could be incorporated in high proportions in the copolymer. We also found that, with the same reaction time, the amount of benzoyl peroxide (BPO) has little or no effect on the polymerization degree; however reaction rates and yields were affected in DMF. All homopolymers showed a low dispersion (?), even when they were polymerized in solution. All DPNAMs can be classified as monodisperse.     

Effects of Ionic Liquid [Me3NC2H4OH]+[ZnCl3]− on γ‐Radiation Polymerization of Methyl Methacrylate in Ethanol and N,N‐Dimethylformamide

Summary: Radiation‐induced polymerization of methyl methacrylate (MMA) in ethanol (EtOH) and N,N‐dimethylformamide (DMF) in the presence of ionic liquid [Me₃NC₂H₄OH]⁺[ZnCl₃]⁻ is reported. A substantial increase in monomer conversion and molecular weight is observed at room‐temperature ionic liquid (RTIL) >60 vol.‐%, and the resulting PMMA has a broad multimodal MWD. A clear difference in the MWD pattern is noted between EtOH/RTIL and DMF/RTIL systems, probably due to the complicated interactions between the solvent and ionic liquid.

Gel permeation chromatography traces of poly(methyl methacrylate) obtained by radiation polymerization in EtOH/RTIL and DMF/RTIL mixed solvent. Organic/RTIL (v/v): 1) 100:0; 2) 80:20; 3) 60:40; 4); 40:60; 5) 0:100.     

Polymerization of surface-active monomers. VIII. Tacticity of polymers prepared by radical polymerization of quaternary salts of dimethylaminoethyl methacrylate in micellar and isotropic media

The effect of monomer micellization on the polymerization was studied from the standpoint of stereochemistry in the polymerization. Quaternary salts (C_nBr) of dimethylaminoethyl methacrylate with n-alkyl bromide having N (=4, 8 and 12) carbon atoms were polymerized with radical initiators in isotropic and anisotropic media and the resulting polymers were converted to poly (methyl methacrylate) (PMMA) to determine their tacticity. Tacticities of poly (C₁₂Br)s were little affected by initiators and solvents used for their preparations. There was little dependence of the tacticities on alkyl chain length (N) for poly (C_nBr)s prepared in water and dimethylformamide (DMF). Most of polymers produced here conformed to Bernoullian propagation statistics and a definite difference was not found in the tacticities between the polymers prepared in isotropic and anisotropic media. From the results obtained here it was deduced that the micellar aggregation has little influence upon the stereochemistry in the polymerization of the quaternary monomers. © 1994 John Wiley & Sons, Inc.     

Single electron transfer‐living radical polymerization of methyl methacrylate catalyzed by ytterbium powder

Zerovalent ytterbium (Yb) powder is firstly used as a catalyst in single electron transfer‐living radical polymerization of methyl methacrylate initiated by carbon tetrachloride in N, N‐dimethylformamide (DMF) and dimethyl sulfoxide, respectively. Polymerization proceeds in a “living”/controlled way as evidenced by kinetic studies and chain extension results, producing well‐defined polymers with controlled degree of polymerization and narrow molecular weight distribution. The apparent activation energy of polymerization in DMF is accounted to be 36.2 kJ/mol, and the energy of equilibrium state is calculated to be 13.9 kJ/mol. An increase in the concentration of Yb(0) yields a higher monomer conversion. It is observed that polymerization rate experiments a rapid increase in the presence of more polar solvent water, and increasing in the content of H₂O results in an increase in the apparent rate constant of polymerization, and a decrease in the molecular weight distribution. The reaction rate and molecular weight increase along with the decrease of DMF content. The effect of Yb(0) powder content, different ligands and concentration of initiator on the polymerization is also investigated. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Electrochemical and chemical polymerization of acrylamide

The electrochemical and chemical polymerization of acrylamide (AA) has been studied. The electrolysis of the monomer in N,N-dimethylformamide (DMF) containing (C₄H₉)₄NClO₄ as the supporting electrolyte leads to polymer formation in both anode and cathode compartments. The cathodic polymer dissolves in the reaction mixture and the anodic polymer precipitates during the course of polymerization. A plausible mechanism for the anodic and cathodic initiation reaction has been given. The chemical polymerization of acrylamide that has been initiated by HClO₄ is analogous to its anodic polymerization. The polymer yield increases with an increase in concentration of the monomer and HClO₄. Raising the reaction temperature also enhances the polymerization rate. The overall apparent activation energy of the polymerization was determined to be ca. 19 kcal/mole. The copolymerization of acrylamide was carried out with methyl methacrylate (MMA) in a solution of HClO₄ in DMF. The reactivity ratios are r₁ (AA) = 0.25 and r₂ = 2.50. The polymerization with HClO₄ appears to be by a free radical mechanism. When the polymerization of acrylamide is carried out with HClO₄ in H₂O, a crosslinked water-insoluble gel formation takes place.     

Kinetic studies of nonaqueous polymerization of methyl methacrylate initiated by ferric laurate–n-hexyl amine system

The polymerization of methyl methacrylate was studied in carbon tetrachloride medium with ferric laurate, a metal soap, in combination with n-hexyl amine as the initiator system at 60°C. The rate of polymerization was found to be linear with the monomer concentration and proportional to the square root of both ferric ion and amine concentration. A reaction scheme involving initial complex formation between ferric ion and amine and subsequent reaction of the complex with the solvent molecule to produce free radicals responsible for initiation of polymerization has been postulated to account for the observed results.     

<Emphasis Type="Italic">N</Emphasis>-hydroxyphthalimide-initiated radical polymerization of vinyl monomers

The initiating ability of N-hydroxyphthalimide in polymerization of methyl methacrylate and acrylonitrile was examined. For the polymerization of methyl methacrylate, the initial polymerization rates and activation energies were determined, and the dependences of the polymerization rates on the initiator and monomer concentrations were evaluated. An initiation mechanism was suggested.     

Synthesis of aromatic polyethersulfone‐based graft copolyacrylates via ATRP catalyzed by FeCl2/isophthalic acid

The atom transfer radical polymerization (ATRP) catalyzed by the FeCl₂/isophthalic acid system was used for the preparation of novel aromatic polyethersulfone (PSF)‐based graft copolymers in N,N‐dimethylformamide (DMF), such as aromatic PSF‐graft‐poly(methyl methacrylate), aromatic PSF‐graft‐polymethylacrylate, and aromatic PSF‐graft‐poly(butyl acrylate). The route consisted of two steps. The first step included the chloromethylation of aromatic PSF, and the second step involved the ATRP of acrylate monomers using chloromethylated aromatic PSF as the macroinitiator and FeCl₂/isophthalic acid as the catalyst in DMF. Characterization data by gel permeation chromatography, DSC, IR, ¹H NMR, and thermogravimetric analysis confirmed that the graft copolymerization was successful. Only one glass‐transition temperature (T_g) was observed for aromatic PSF‐graft‐poly(methyl methacrylate), and two T_g's were detected for aromatic PSF‐graft‐methyl acrylate and aromatic PSF‐graft‐poly(butyl acrylate). © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2943–2950, 2001     

Surface modification of polystyrene latex particles via atom transfer radical polymerization

The atom transfer radical polymerization (ATRP) technique using the copper halide/ N,N′,N′,N″,N″‐pentamethyldiethylenetriamine complex was applied to the graft polymerization of methyl methacrylate and methyl acrylate on the uniform polystyrene (PS) seed particles and formed novel core‐shell particles. The core was submicron crosslinked PS particles that were prepared via emulsifier‐free emulsion polymerization. The crosslinked PS particles obtained were transferred into the organic phase (tetrahydrofuran), and surface modification using the chloromethylation method was performed. Then, the modified seed PS particles were used to initiate ATRP to prepare a controlled poly(methyl methacrylate) (PMMA) and poly(methyl acrylate) (PMA) shell. The final core‐shell particles were characterized using Fourier transform infrared spectroscopy, nuclear magnetic resonance, scanning electron microscopy, thermogravimetric analysis, and elementary analysis. The grafting polymerization was conducted successfully on the surface of modified crosslinked PS particles, and the shell thickness and weight ratio (PMMA and PMA) of the particles were calculated. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 892–900, 2002; DOI 10.1002/pola.10160     

Anionic polymerization of vinyl monomers with xanthates

The polymerization of vinyl monomers with various xanthates (potassium tert-butylxanthate, potassium benzylxanthate, zinc n-butylxanthate, etc.) were carried out at 0°C in dimethylformamide. N-Phenylmaleimide, acrylonitrile, methyl vinyl ketone, and methyl methacrylate were found to undergo polymerization with potassium tert-butylxanthate; however, styrene, methyl acrylate, and acrylamide were not polymerized with this xanthate. In the anionic polymerization of methyl vinyl ketone with potassium tert-butylxanthate, the rate of the polymerization was found to be proportional to the catalyst concentration and to the square of the monomer concentration. The activation energy of methyl vinyl ketone polymerization was 2.9 kcal/mole. In the polymerization, the order of monomer reactivity was as follows: N-phenylmaleimide > methyl vinyl ketone > acrylonitrile > methyl methacrylate. The initiation ability of xanthates increased with increasing basicity of the alkoxide group and with decreasing electronegativity of the metal ion in the series, lithium, sodium, and potassium tert-butylxanthate. The relative effects of the aprotic polar solvents on the reactivity of potassium tert-butylxanthate was also determined as follows: diethylene glycol dimethyl ether > dimethylsulfoxide > hexamethylphosphoramide > dimethylformamide > tetrahydrofuran (for methyl vinyl ketone); dimethyl sulfoxide > hexamethylphosphoramide > dimethylformamide ? diethylene glycol dimethyl ether (for acrylonitrile).     

In situ Fourier transform near infrared spectroscopy monitoring of copper mediated living radical polymerization

In situ Fourier transform near infrared (FTNIR) spectroscopy was successfully used to monitor monomer conversion during copper mediated living radical polymerization with N‐(n‐propyl)‐2‐pyridylmethanimine as a ligand. The conversion of vinyl protons in methacrylic monomers (methyl methacrylate, butyl methacrylate, and N‐hydroxysuccinimide methacrylate) to methylene protons in the polymer was monitored with an inert fiber‐optic probe. The monitoring of a poly(butyl methacrylate‐b‐methyl methacrylate‐b‐butyl methacrylate) triblock copolymer has also been reported with difunctional poly(methyl methacrylate) as a macroinitiator. In all cases FTNIR results correlated excellently with those obtained by ¹H NMR. On‐line near infrared (NIR) measurement was found to be more accurate because it provided many more data points and avoided sampling during the polymerization reaction. It also allowed the determination of kinetic parameters with, for example, the calculation of an apparent first‐order rate constant. All the results suggest that FTNIR spectroscopy is a valuable tool to assess kinetic data. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4933–4940, 2004     

Spontaneous Cu(I)Br–PMDETA‐mediated polymerization of isobornyl methacrylate in heterogeneous aqueous medium at ambient temperature

Isobornyl methacrylate (IBMA), a bulky hydrophobic methacrylate, undergoes very fast polymerization, in bulk, with Cu(I)Br/N,N,N′,N″,N″‐pentamethyldiethylenetriamine (PMDETA)/ethyl‐2‐bromoisobutyrate system, at ambient temperature. IBMA also undergoes a spontaneous initiator‐free polymerization, at ambient temperature, with Cu(I)Br/PMDETA catalytic system in dimethyl sulfoxide–water mixtures. The rate of the polymerization is seen to increase with the water content up to 80 mol % of water. A possible intervention of air in initiation is proposed. The active Cu(0) formed by the disproportionation of Cu(I) species in aqueous medium probably plays a vital role for a possible air‐initiation of IBMA via single electron transfer‐living radical polymerization (SET‐LRP) mechanism. A high tolerance level to water under SET‐LRP conditions is demonstrated. The poly(IBMA) samples obtained exhibit low molecular weight distributions (1.1–1.3). Similar behavior was not observed with other common methacrylates such as methyl methacrylate, t‐butyl methacrylate, cyclohexyl methacrylate, and benzyl methacrylate. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Inhibited Polymerization of N,N,N-Trimethylammonioethyl Methacrylate Methyl Sulfate

The kinetic features of initiation of N,N,N-trimethylammonioethyl methacrylate methyl sulfate polymerization in the presence of manganese(III) bis(acetylacetonate) nitrate and p-nitrosoaniline were studied by the inhibited polymerization method. The kinetic parameters of initiation were calculated, and participation of the monomer in the initiation stage was established.     

Controlled polymerization of methyl methacrylate in the presence of an FeCl3-complexing agent system

The controlled polymerization of methyl methacrylate in DMF with participation of FeCl₃ and ligands (acrylamide, 1,1,1,3,3,3-hexamethyldisilazane, citric acid, and sulfosalicylic acid) has been studied. It has been shown for the first time that DMF ensures the polymerization of methyl methacrylate in the controlled mode without any other complexing agents. As temperature increases, the rate of the process and the polydispersity of PMMA increase.     

Atom transfer radical polymerization of methyl methacrylate catalyzed by ion exchange resin immobilized Co(II) hybrid catalyst

Ion exchange resin immobilized Co(II) catalyst with a small amount of soluble CuCl₂/Me₆TREN catalyst was successfully applied to atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA) in DMF. Using this catalyst, a high conversion of MMA (>90%) was achieved. And poly(methyl methacrylate) (PMMA) with predicted molecular weight and narrow molecular weight distribution (M_w/M_n = 1.09–1.42) was obtained. The immobilized catalyst can be easily separated from the polymerization system by simple centrifugation after polymerization, resulting in the concentration of transition metal residues in polymer product was as low as 10 ppm. Both main catalytic activity and good controllability over the polymerization were retained by the recycled catalyst without any regeneration process. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1416–1426, 2008     

Microwave‐Assisted Free Radical Polymerizations and Copolymerizations of Styrene and Methyl Methacrylate

Summary: Radical homopolymerizations and copolymerizations of styrene were performed in toluene and N,N‐dimethylformamide (DMF) as solvents using different initiators with and without microwave irradiation. Only the homopolymerization of styrene under microwave irradiation in DMF with DtBP showed significantly enhanced styrene conversion whereas other initiators resulted in no or only slight increase of styrene conversion under microwave irradiation. In any case, DMF was required to gain in styrene conversion under microwave irradiation. Significantly higher monomer conversions were observed under otherwise comparable conditions in the copolymerization of styrene and methyl methacrylate (MMA) in DMF. Microwave‐induced selectivity of monomers was not observed in copolymerizations.

Yield of styrene polymerizations under varying reaction conditions initiated by DtBP.     

Radical polymerizations and copolymerizations of dimethylstannyl dimethacrylate and trimethylstannyl methacrylate

The radical polymerizations and copolymerizations of dimethylstannyl dimethacrylate (DSM) and trimethylstannyl methacrylate (TSM) in dimethylformamide (DMF) were studied. These monomers did not polymerize thermally, but easily underwent polymerization in the presence of α,α′-azobisisobutyronitrile and on irradiation with ultraviolet light. The polymer obtained from TSM was soluble in DMF and methanol, but that from DSM was insoluble in any organic solvents; this polymer probably consists of a network structure. These polymers were converted to poly(methyl methacrylate) (PMMA) by means of acid hydrolysis and then methylation with diazomethane. The content of syndiotactic triad was determined from infrared spectra of PMMA derived from the polymers of DSM and TSM. It was noted that the content of syndiotactic triad was greater in the radical polymerization of TSM than those of DSM at every temperature investigated. The differences in the activation enthalpy (ΔΔH?) and in the activation entropy (ΔΔS?) between isotactic and syndiotactic additions were determined as follows: for DSM, ΔΔH? = ～0 cal/mole, ΔΔS? = ?0.856 eu; for TSM, ΔΔH? = 229 cal/mole, ΔΔ = ?1.09 eu. From the radical copolymerizations of DSM and TSM with styrene at 60°C, the copolymerization parameters, Q and e, were evaluated as follows: for DSM, Q = 1.36, e = 0.41; for TSM, Q = 0.45, e = ?0.37. These results were compared with the reported effects of stannic chloride and zinc chloride on the radical polymerization of methyl methacrylate.