Reactivity ratios of free monomers and their charge‐transfer complex in the copolymerization of N‐butyl maleimide and styrene

As for the charge‐transfer complex (CTC) formed by N‐butyl maleimide (NMBI) and styrene in chloroform, the complex formation constant was determined by ¹H‐NMR of Hanna–Ashbaugh. The copolymerization of NBMI (NBMI, M₁) and styrene (St, M₂) in chloroform using AIBN as an initiator was investigated. On the basis of the kinetic model proposed by Shan, the reactivity ratios of free monomers and CTC in the copolymerization were calculated to be r₁₂ = 0.0440, r₂₁ = 0.0349, r_1C = 0.00688, r_2C = 0.00476, and the ratios of rate constants were obtained to be k_1C/k₁₂ = 6.40, k_2C/k₂₁ = 7.33. In addition, the copolymer was characterized by IR, ¹H‐NMR, DSC, and TGA. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 3007–3012, 2002; DOI 10.1002/app.2330     

Synthesis and characterization of styrene–acrylic ester copolymers

Homopolymers and copolymers of styrene and different acrylic esters (i.e., acrylates) were synthesized by the free‐radical solution polymerization technique. Feed ratios of the monomers styrene and cyclohexyl acrylate/benzyl acrylate were 90 : 10, 75 : 25, 60 : 40, 50 : 50, 40 : 60 and 20 : 80 (v/v) in the synthesis of copolymers. All 6 homopolymerizations of acrylic ester synthesis were carried out in N,N(dimethyl formamide) except for the synthesis of poly(cyclohexyl acrylate) (PCA), where the medium was 1,4‐dioxane. Benzoyl peroxide (BPO) and azobisisobutyronitrile (AIBN) were used as initiators. The polymers synthesized were characterized by FTIR, ¹H‐NMR, ¹³C‐NMR spectroscopy, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and viscosity measurements. The reactivity ratios were determined by the Fineman–Ross method using ¹H‐NMR spectroscopic data. The reactivity ratios (r) for the copolymerization of styrene (r_S) with cyclohexyl acrylate (r_CA) were found to be r_S = 0.930 and r_CA = 0.771, while for the copolymerization of styrene with benzyl acrylate, the ratios were found to be r_S = 0.755 and r_BA = 0.104, respectively. The activation energies of decomposition (E_a) and glass‐transition temperature (T_g) for various homo‐ and copolymers were evaluated using TGA and DSC analysis. The activation parameters of the viscous flow, voluminosity (V_E) and shape factor (ν) were also computed for all systems using viscosity data. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 1513–1524, 2001     

Controllable radical copolymerization of styrene and methyl methacrylate using 1,1,2,2‐tetraphenyl‐1,2‐bis(trimethylsilyloxy) ethane as initiator

Copolymerization of styrene (St) and methyl methacrylate (MMA) was carried out using 1,1,2,2‐tetraphenyl‐1,2‐bis (trimethylsilyloxy) ethane (TPSE) as initiator; the copolymerization proceeded via a “living” radical mechanism and the polymer molecular weight (M_w) increased with the conversion and polymerization time. The reactivity ratios for TPSE and azobisisobutyronitrile (AIBN) systems calculated by Finemann–Ross method were r_St = 0.216 ± 0.003, r_MMA= 0.403 ± 0.01 for the former and r_St= 0.52 ± 0.01, r_MMA= 0.46 ± 0.01 for the latter, respectively, and the difference between them and the effect of polymerization conditions on copolymerization are discussed. Thermal analysis proved that the copolymers obtained by TPSE system showed higher sequence regularity than that obtained by the AIBN system, and the sequence regularity increased with the content of styrene in copolymer chain segment. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1474–1482, 2001     

Effect of partitioning of monomer on the reactivities of monomers in microemulsion

Copolymerization of styrene and 2‐hydroxyethyl methacrylate (2‐HEMA) was carried out in a microemulsion medium. The composition of the copolymers was estimated using proton ¹H‐NMR. The reactivity ratios of styrene and 2‐HEMA in ternary microemulsions were observed and were considerable different from those reported for solution and bulk polymerization. In monomer pairs with a considerable difference in polarity, partitioning of a monomer between the aqueous phase and the microemulsion droplets develops a concentration gradient, which can be calculated from the distribution coefficient of the monomer between the two phases. This approach has led to more reliable reactivity ratios for the monomers. The study of styrene–2‐HEMA copolymerization in a sodium dodecylsulfate‐based microemulsion resulted in r_S = 3.79 and r_H = 0.17 as apparent reactivity ratios and r_S = 0.57 and r_H = 23.24 as true reactivity ratios for styrene and 2‐HEMA, respectively. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1832–1837, 2002; DOI 10.1002/app.10401     

Additive modification of the polymerization and properties of an acrylic bone cement

A commercial surgical bone cement has been modified by adding tricalcium phosphate (TCP), hydroxyethyl methacrylate (HEMA), and ethylene glycol dimethacrylate (EGDMA). The effects of the addition of TCP, HEMA, and EGDMA on the vinyl polymerization kinetics and thermal stability of the bone cement have been evaluated. The reaction rate constants (k) were determined from a kinetic analysis. The separate and combined effects of TCP, HEMA, and EGDMA contents on the rate and the heat of polymerization can be explained by the frequency factor and the activation energy. The decomposition temperture of the modified acrylic bone cement was studied by thermogravimetry. The decomposition temperature increased with TCP content, whereas HEMA and EGDMA had little effect on the decomposition temperature.     

The copolymerization of N-vinyl-2-pyrrolidone with 2-hydroxyethyl methacrylate

Summary The bulk free radical copolymerization of 2-hydroxyethyl methacrylate (HEMA) with N-vinyl-2-pyrrolidone (VP) was carried out to low conversions at 50 °C, using benzoyl peroxide (BPO) as initiator. The compositions of the copolymers were determined using ¹³C NMR spectroscopy. The conversion of monomers to polymers was studied using FT-NIR spectroscopy in order to predict the extent of conversion of monomer to polymer. From model fits to the composition data, a statistical F-test revealed that the penultimate model describes the copolymerization better than the terminal model. Reactivity ratios were calculated by using a non-linear least squares analysis (NLLS) and r _H = 8.18 and r _V = 0.097 were found to be the best fit values of the reactivity ratios for the terminal model and r _HH = 12.0, r _VH = 2.20, r _VV = 0.12 and r _HV = 0.03 for the penultimate model. Predictions were made for changes in compositions as a function of conversion based upon the terminal and penultimate models. Received: 27 Febuary 2001/Revised version: 5 November 2001/Accepted: 6 November 2001     

Monomer reactivity ratios for acrylonitrile/ammonium itaconate during aqueous‐deposited copolymerization initiated by ammonium persulfate

Monomer reactivity ratios of acrylonitrile/ammonium itaconate during aqueous‐deposited copolymerization initiated by ammonium persulfate were investigated. Kelen–Tudos method was used to examine the reactivity ratios. It was shown that the reactivity ratios were influenced by the conversions and temperatures of copolymerization. The reactivity ratios in aqueous‐deposited copolymerization system were similar to those in the solution polymerization system at polymerization conversions of less than 5% [reactivity ratio of acrylonitrile (r₁) 0.842 ± 0.02, reactivity ratio of ammonium itaconate (r₂) = 3.624 ± 0.02]. The reactivity ratio of AN rises and that of (NH₄)₂IA decreases, when the polymerization conversion increases till 13%. Aqueous‐deposited copolymerization initiated by AIBN was also studied. It was found that some polymers were formed in water phase and the monomers had different reactivity ratios by comparison with those initiated by ammonium persulfate. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4645–4648, 2006     

Free‐radical copolymerization kinetics of acrylonitrile and methyl acrylate in [BMIM]BF4

The copolymerization of acrylonitrile (AN) and methyl acrylate (MA) was carried out in ionic liquid [BMIM]BF₄ in the presence of azobisisobutyronitrile (AIBN) as an initiator to investigate the polymerization kinetic, including the copolymerization rate, reactivity ratios, and activation energy. The copolymerization rate equation was established according to the effect of initiator and monomer concentrations on the conversion. The copolymerization rate R_p can be noted as , when the copolymerization was in the steady state. The apparent activation energy is 87.94 kJ/mol, while the value of that in the conventional organic solvent (DMF) is ∼ 81 kJ/mol. The reactivity ratios of the investigate system are r_AN = 0.36 and r_MA = 0.68. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4254–4257, 2006     

Determination of monomer reactivity ratios using in situ FTIR spectroscopy for maleic anhydride/norbornene‐free‐radical copolymerization

Monomer reactivity ratios for maleic anhydride (MAH) and norbornene (Nb) free‐radical copolymerizations were estimated by using a linear graphical method, which is based upon the terminal model developed by Mayo and Lewis. Reactions were performed by using optimized reaction conditions that were previously determined. MAH/Nb copolymerizations (3 mol % AIBN initiator, 60% solids in THF, 65°C, 24 h). Copolymerization data were collected via in situ FTIR to low degrees of conversion (～ 10%) for copolymerizations of MAH and Nb. The following five different MAH/Nb comonomer feed molar ratios were analyzed: 40/60, 45/55, 50/50, 55/45, and 60/40. Conversion data that were measured with in situ FTIR were employed in the rearranged copolymer composition equation to estimate MAH and Nb reactivity ratios. Both of the reactivity ratios were determined to be near 0 (r_MAH = 0.02, r_Nb = 0.01), which was indicative of an alternating copolymerization mechanism. The highest observed rate constant for copolymerization was obtained at an equal molar concentration of monomers. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3240–3246, 2004     

Investigations of the copolymerization of acrylonitrile with vinyl acetate and sodium methallylsulfonate

The bulk copolymerizations of acrylonitrile (AN) with vinyl acetate (VAc) initiated by azobisisobutyronitrile (AIBN) and the suspension copolymerization of AN with VAc and sodium methallylsulfonate (SMAS) in water with a Na₂S₂O₅–Na₂ClO₃ redox initiator system at 65°C, were investigated. The copolymer compositions were determined by ¹H-NMR. The reactivity ratios (γs) for the two copolymerization systems were determined analytically, based on Mayo–Lewis equation, by fitting the calculated curves with the experimental data. The γs for the AN and VAc bulk copolymerization were found to be γ₁₂ = 2.85 and γ₂₁ = 0.11. The values of the apparent γs for the suspension copolymerization of AN, VAc, and SMAS were as follows: γ₁₂ = 3.58, γ₂₁ = 0.39, γ₁₃ = 1.45, γ₃₁ = 0, γ₂₃ = 0.92, and the rate constant ratio R₃ = k₃₁/k₃₂ = 0.04. A simulated result produced with the obtained γs agreed fairly well with experimental data of bulk copolymerization in a batch reactor. The apparent γs obtained were also successfully used to analyze the results of suspension polymerization in a continuous pilot reactor.© 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 854–860, 2001     

Radical polymerization and copolymerization behavior of 1-cyanoethanoyl-4-acryloylthiosemicarbzide

1-Cyanoethanoyl-4-acryloylthiosemicarbazide (CEATS) was synthesized for the first time as a new chelating monomer. Its structure was confirmed by both elemental and spectral analyses. Radical polymerization and copolymerization of CEATS was been carried out in dimethylformamide (DMF) in the presence of azobisisobutyronitrile (AIBN) as an initiator. Kinetic studies for the polymerization behavior of CEATS were performed. The complex formation of the CEATS monomer and polymer (PCEATS) with Cu II cation was investigated and its stability constant determined. The rate of copolymerization of CEATS with some conventional monomers, namely vinyl acetate, methyl methacrylate and acrylonitrile, was measured as a function of the mole fraction of the monomers. The reactivity ratios (r₁, r₂) for the various copolymer systems investigated together with the Q and e values of the CEATS monomer were determined. Moreover, the thermal gravimetric analysis of the prepared polymers and their copolymers with acrylonitrile were also studied.     

New functional copolymers of <Emphasis Type="Italic">N</Emphasis>-acryloyl-<Emphasis Type="Italic">N</Emphasis>′-methyl piperazine and 2-hydroxyethyl methacrylate: synthesis,determination of reactivity ratios and swelling characteristics of gels

Copolymers of N-acryloyl-N′-methylpiperazine (AcrNMP) and 2-hydroxyethyl methacrylate (HEMA) were synthesized by free radical solution polymerization in dioxane at 70 ± 1 °C, using 2,2′-azobisisobutyronitrile (AIBN) as initiator. The copolymer compositions were analyzed by the methods of FTIR spectroscopy and elemental analysis. Both the method of analysis yielded results that agreed reasonably well. The monomer reactivity ratios of the copolymerization were determined by the linearization methods of Finemann–Ross (FR) and Kelen–Tüdös (KT). The reactivity parameter results derived using FTIR analysis showed that the copolymerization yielded mainly alternating structure with reactivity ratios, r ₁(AcrNMP) = 0.263 ± 0.011 and r ₂(HEMA) = 0.615 ± 0.097 by F–R method and r ₁ = 0.227 ± 0.074 and r ₂ = 0.53 ± 0.15 by KT method. Microstructure data calculated by the method of Igarashi also supports the alternating structure (tendency) of the copolymer. Crosslinked polymer gels of this system exhibited remarkably high swelling of more than 500% in water at ambient temperature.     

Effect of stannous octoate on the thermal decomposition of 2,2′‐azobis(isobutyronitrile)

The thermal decomposition rate constant k_d of 2,2′‐azobis(isobutyronitrile) (AIBN) in ethyl acetate was determined at 60 °C in the presence of various amounts of stannous octoate (SnOc₂). The k_d values were found to be dependent on the concentration of SnOc₂ in the solution. This dependence is not a linear function of the concentration because k_d goes through a maximum when [SnOc₂]/[AIBN] = 1. These features were explained by assuming the formation of a 1:1 cyclic complex between the nitrile groups of AIBN and the tin atom of SnOc₂. This complex induces steric constraints in the azo bond of AIBN, thus increasing its rate of decomposition. © 2000 Society of Chemical Industry     

Semicontinuous emulsion copolymerization of acrylonitrile,butyl acrylate,and styrene

Semicontinuous emulsion copolymerization of acrylonitrile (M₁), butyl acrylate (M₂), and styrene (M₃) was investigated. The copolymerization proceeded under the conditions used with a high degree of conversion, whereby a stationary state characterized by a constant monomer mixture composition and a constant composition of the arising copolymer was achieved. From the analytically estimated free monomers and arising copolymer compositions, the reactivity ratios for the pair AN/BA r₁₂ = 0.71, r₂₁ = 1.17 and for the pair AN/Sty r₁₃ = 0.06, r₃₁ = 0.28 were calculated. The applicability of the reactivity ratios found was verified also for the ternary system acrylonitrile/butyl acrylate/styrene.     

Combination of nuclear magnetic resonance spectroscopy and nonlinear methods to analyze the copolymerization of phosphonic acid derivatives

We demonstrate in this study that the combination of modern inline monitoring methods [here: inline nuclear magnetic resonance (NMR)] with simulations gains more exact and profound kinetic results than previously used methods like linearization without that combination. The ¹H-NMR spectroscopic data (more than 100 data points) are used to construct the copolymerization diagram. The reactivity ratios are obtained applying the van Herks nonlinear least square method. The examination of the radical copolymerization of 2-hydroxyethyl methacrylate (HEMA) with (2-{[2-(ethoxycarbonyl)prop-2-en-1-yl]oxy}ethyl) phosphonic acid (ECPPA) as important adhesive monomer used in dentistry yields reactivity ratios of r_HEMA = 1.83; r_ECPPA = 0.42. The copolymerization diagram reflects nonideal, non-azeotropic copolymerization. The sequence distribution of the obtained by Monte Carlo simulation indicates the generation of statistical copolymers. As an important finding, it is demonstrated that the repeating units responsible for etching and adhesion are arranged over the whole polymer chain, which is necessary to achieve proper functionality. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48256.     

Synthesis and characterization of copolymers of bromoacrylated methyl oleate

In this study, methyl oleate was bromoacrylated in the presence of N‐bromosuccinimide and acrylic acid in one step. Homopolymers and copolymers of bromoacrylated methyl oleate (BAMO) were synthesized by free radical bulk polymerization and photopolymerization techniques. Azobisisobutyronitrile (AIBN) and 2,2‐dimethoxy‐2‐phenyl‐acetophenone were used as initiators. The new monomer BAMO was characterized by FTIR, GC‐MS, ¹H, and ¹³C‐NMR spectroscopy. Styrene (STY), methylmethacrylate (MMA), and vinyl acetate (VA) were used for copolymerization. The polymers synthesized were characterized by FTIR, ¹H‐NMR, ¹³C‐NMR, and differential scanning calorimetry (DSC). Molecular weight and polydispersities of the copolymers were determined by GPC analysis. Ten different feed ratios of the monomers STY and BAMO were used for the calculation of reactivity ratios. The reactivity ratios were determined by the Fineman–Ross and Kelen–Tudos methods using ¹H‐NMR spectroscopic data. The reactivity ratios were found to be r_sty = 0.891 (Fineman–Ross method), 0.859 (Kelen–Tudos method); r_bamo = 0.671 (Fineman–Ross method), 0.524 (Kelen–Tudos method). © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 2475–2488, 2004     

Copolymerization of 2-methyl-N-1,3-thiazole-2-ylacrylamide with glycidyl methacrylate: synthesis, characterization, reactivity ratios and biological activity

The free-radical copolymerization of 2-methyl-N-1,3-thiazole-2-ylacrylamide monomer (TMA) with glycidyl methacrylate (GMA) was carried out in 1,4-dioxane at 65 ± 1 °C using azobisisobutironitril (AIBN) as an initiator. The copolymers were characterized by FTIR, ¹³C-NMR and ¹H-NMR spectroscopic methods. The copolymer compositions were determined by elemental analysis. The weight-average and number-average molecular weights of the copolymers were obtained by gel permeation chromatography (GPC). The polydispersity indices of the polymers, determined with gel permeation chromatography, suggested a strong tendency for chain termination by disproportionation. Thermal properties of the polymers were also studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The monomer reactivity ratios were calculated according to the general copolymerization equation using Kelen–Tudos and Fineman–Ross linearization methods. The reactivity ratios indicated a tendency toward for alternation. The thermal decomposition activation energies of the polymers were evaluated by Ozawa method. The antibacterial and antifungal effects of the copolymers were also investigated on various bacteria and fungi. All the products showed moderate activity against different strains of bacteria and fungi.     

Synthesis of substituted polymethylenes from acenaphthylene by radical polymerization and copolymerization

Radical polymerization of acenaphthylene (Ace) as a 1,2-disubstituted ethylene was investigated. It was found that the polymerization rate (R_p) was expressed as follows: R_p = k[Ace]^1.0[AIBN]^0.68, and that the overall activation energy was 113 kJ/mol for polymerization with 2,2'-azobisisobutyronitrile (AIBN) in benzene at 50–70°C. Poly(Ace) obtained was characterized by NMR spectroscopy and GPC. Some substituted copolymethylenes were also prepared by radical copolymerization of Ace with other 1,2-disubstituted ethylenes, that is, maleic anhydride, diisopropyl fumarate, and N-cyclohexylmaleimide. The monomer reactivity ratios were determined from comonomer–copolymer composition curves.     

Organotin polymers. IV. Binary and ternary copolymerizations of tributyltin acrylate and methacrylate with styrene,allyl methacrylate,butyl methacrylate,butyl acrylate,and acrylonitrile

The monomer reactivity ratios for the copolymerization of tributyltin acrylate with styrene and allyl methacrylate have been found to be r₁ = 0.213, r₂ = 1.910 and r₁ = 0.195, r₂ = 2.257, respectively. Also, the copolymerization parameters of tributyltin methacrylate with styrene and allyl methacrylate were as follows: r₁ = 0.256, r₂ = 1.104 and r₁ = 2.306, r₂ = 1.013. Copolymerization reactions were carried out in solution at 70°C using 1 mole % AIBN, and the copolymer compositions were determined by tin analysis. Ternary copolymerization of the three systems butyl methacrylate–tributyltin methacrylate–acrylonitrile, butyl acrylate–tributyltin methacrylate–acrylonitrile, and styrene–tributyltin acrylate–acrylonitrile have been studied, and the terpolymer composition of each system was determined through tin and nitrogen analyses. The variation of instantaneous and average terpolymer composition with conversion fit satisfactorily the experimental results over a wide range of conversion.     

Copolymerizations of tetrafluoroethylene and perfluoropropylvinyl ether in supercritical carbon dioxide: Polymer synthesis,characterization, and thermal properties

Tetrafluoroethylene (TFE) and perfluoropropylvinyl ether (PPVE) were copolymerized in supercritical carbon dioxide (sc‐CO₂) with a perfluorodiacyl initiator bis(perfluoro‐2‐n‐propoxypropionyl) peroxide (BPPP). The resultant copolymers with stable perfluoroalkyl end groups were obtained, avoiding the decomposition during processing and applications. Reactivity ratios of TFE and PPVE were first reported. The r_TFE and r_PPVE values are about 8 and 0.08, respectively. Such parameters are significant for the modification of PTFE through copolymerization of TFE and PPVE. It is found that through increasing the reaction pressure from 8.5 to 25 MPa, while r_TFE increases by 12.0%, r_PPVE decreases by 9.0%, which should be ascribed to the enhancement of the polarity of CO₂ under high pressures. Because the reactivity of TFE is by two orders of magnitude higher than that of PPVE; on one hand, the copolymerization rate falls rapidly with the decrease of TFE feed ratio; on the other hand, TFE content in the copolymer decreases with the reaction time. All copolymers containing different fractions of PPVE enjoy outstanding thermal stability. The DSC result indicates that there exist two forms of crystals with highly regular molecular arrangement or less ordered chain packing which is disturbed by perfluoropropyl pendants. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012