Copolymerization of Methyl Methacrylate,Ethyl Acrylate,and Butyl Acrylate with N-2-Anisylmaleimide and Characterization of the Copolymers

The free radical copolymerizations of methyl methacrylate (MMA), ethyl acrylate (EA), and butyl acrylate (BA) with N-2-Anisylmaleimide (AMI), initiated by AIBN, were performed in THF solvent at 65°C. A series of copolymers of AMI-MMA, AMI-EA, and AMI-BA were prepared using different feed ratios of comonomers. The polymer samples have been characterized by solubility tests, intrinsic viscosity measurements, FT-IR, and ¹H-NMR spectral analysis, and thermo-gravimetric analysis. The values of monomer reactivity ratios r₁ and r₂ determined by Fineman-Ross and Kelen-Tudos methods are 0.43 and 0.42 in AMI/MMA, 0.72 and 0.62 in AMI/EA and 0.76 and 0.72 in AMI/BA systems. Alfrey-Price Q-e values for AMI are Q = 3.13 and e = 1.71 in AMI/MMA, Q = 1.10 and e = 1.46 in AMI/EA and Q = 1.02 and e = 1.63 in AMI/BA systems. It was found that the initial and final decomposition temperature increased with increasing the component of AMI in the copolymer.     

Synthesis and Characterization of Homo- and Copolymers of N-4-Azodiphenyl Maleimide with Methyl Methacrylate and Styrene

The synthesis and free radical homopolymerization of N-4-azodiphenylmaleimide (ADPMI) and copolymerization of methyl methacrylate (MMA) and styrene (ST) with ADPMI using an AIBN initiator were performed in THF solvent at 70°C. A series of copolymers, ADPMI-MMA and ADPMI-ST, were prepared using different feed ratios of comonomers. The polymer samples have been characterized by solubility tests, intrinsic viscosity measurements, FT-IR, ¹H-NMR spectral analysis, and thermo-gravimetric analysis. The values of monomer reactivity ratios r₁ and r₂ determined by Fineman-Ross and Kelen-Tudos methods are 0.16 and 0.63, and 0.26 and 0.25 in ADPMI/MMA and ADPMI/ST systems, respectively. Alfrey-Price Q-e values for ADPMI are Q = 2.27 and e = 1.92, and 0.41 and 1.949 for ADPMI/MMA and ADPMI/ST systems, respectively. It was found that the initial and final decomposition temperatures increased with the increase of ADPMI content in the copolymer samples.     

Synthesis and Radical Copolymerization of Ethyl Acrylate and Butyl Acrylate with N-[4-N'-(Phenylamino-carbonyl) phenyl] maleimide

Radical copolymerization of ethyl acrylate (EA) and butyl acrylate (BA) with 4-maleimidobenzanilide (MB), that is N-[4-N′-(phenylaminocarbonyl)phenyl]maleimide, initiated by AIBN was performed in THF solvent at 65°C. Nine copolymer samples of each type were prepared using different feed ratios of comonomers. All the polymer samples have been characterized by solubility test, intrinsic viscosity measurements, FT-IR and ¹H-NMR spectral analysis, and thermo-gravimetric analysis. The values of monomer reactivity ratios r₁ and r₂ are 1.13 and 0.48 in MB/EA system and 0.45 and 0.52 MB/BA system. Alfrey-Price Q-e values for MB were Q = 1.31 and e = 1.33 in MB/EA and Q = 2.04 and e = 2.06 in MB/BA systems. The initial decomposition temperature of copolymer samples were in the range 310 to 365°C.     

Radical Copolymerization of 2-(3′-Acryloxy)propoxythioxanthone and 1-Methyl-4-(3′-acryloxy)propoxythioxanthone with Methyl Methacrylate

Two new monomers based on thioxanthone, 2-(3′-acryloxy)propoxythioxanthone (M-2) and 1-methyl-4-(3′-acryloxy)propoxythioxanthone (M-4), were prepared and their radical copolymerization at 70°C with methyl methacrylate (MMA) was studied. By varying the conversion reached for a fixed feed composition, f_MMA=0·983, and using Jaacks method, the reactivity ratios were determined. Identical values of reactivity ratios were found for both systems, with values of r_MMA=2·46 and r_M-2=r_M-4=0·4. The homopolymerization of MMA in the presence of a model compound, 1-methyl-4-propoxythioxanthone, was also examined and confirmed that the thioxanthone chromophore does not have any influence on the free radical polymerization of MMA. © of SCI.     

Radiation-induced copolymerization of vinylphosphonic dichloride with methyl methacrylate and styrene

The γ-ray-induced copolymerization of vinylphosphonic dichloride (VPDC) with methyl methacrylate (MMA) and styrene (St) was studied at 25°C (liquid phase) and ?78°C (Solid phase). The reaction mechanisms are discussed. The reactivity ratios for the copolymerization of the VPDC–MMA system were determined as follows: The difference between the reactivity between the liquid-phase (25°C) and solid-phase (?78°C) copolymerization is mainly attributable to the r₂ value. The behavior of the liquid-phase copolymerization of the VPDC–St system was anomalous, the r₁ value being negative in the range from 0 to 80 mole-% of VPDC monomer. In the solid-phase (?78°C) copolymerization for the VPDC–St system, the reactivity ratios r₁ and r₂ were 0.097 and 1.6, respectively. The rate of copolymerization (R_p) at 25°C, for both the VPDC–MMA and VPDC–St systems, passes a maximum point at a certain monomer concentration, suggesting that the composition of copolymer is considerably affected by R_p. This phenomenon was interpreted by the assumption that an energy transfer reaction from VPDC monomer to the other vinyl compound can easily occur.     

Kinetic study of atom transfer radical homo- and copolymerization of styrene and methyl methacrylate initiated with trichloromethyl-terminated poly(vinyl acetate) macroinitiator

Atom transfer radical bulk copolymerization of styrene (St) and methyl methacrylate (MMA) was performed in the presence of CuCl/PMDETA as a catalyst system and trichloromethyl-terminated poly(vinyl acetate) telomer as a macroinitiator at 90 °C. The overall monomer conversion was followed gravimetrically and the cumulative average copolymer composition at moderate to high conversion was determined by ¹H NMR spectroscopy. Reactivity ratios of St and MMA were calculated by the extended Kelen–Tudos (KT) and Mao–Huglin (MH) methods to be r_St = 0.605 ± 0.058, r_MMA = 0.429 ± 0.042 and r_St = 0.602 ± 0.043, r_MMA = 0.430 ± 0.032, respectively, which are in good agreement with those reported for the conventional free-radical copolymerization of St and MMA. The 95% joint confidence limit was used to evaluate accuracy of the estimated reactivity ratios. Results showed that in the controlled/living radical polymerization systems such as ATRP, more reliable reactivity ratios are obtained when copolymer composition at moderate to high conversion is used. Good agreement between the theoretical and experimental composition drifts in the comonomer mixture and copolymer as a function of the overall monomer conversion was observed, indicating the accuracy of reactivity ratios calculated by copolymer composition at the moderate to high conversion. Instantaneous copolymer composition curve and number-average sequence length of comonomers in the copolymer indicated that the copolymerization system tends to produce a random copolymer.     

Synthesis and Characterization of Methylmethacrylate-alt-N-vinyl-2-pyrrolidone Initiated by Phosphorus Containing 1,2 Dipolar Compound

Copolymerization of methylmethacrylate (MMA) with 1-vinyl-2-pyrrolidone (N-VP), initiated by p-nitrobenzyl triphenyl phosphonium ylide in dioxane at 60°C for 60 min under inert atmosphere of nitrogen yields alternating copolymer as evidenced by the values of r ₁ = 0.01 and r ₂ = 0.02. The kinetic expression was R_p ∝ [I]^0.75[MMA]^1.2[VP]^1.2. The overall activation energy is 45.4 kJ/mol. The FTIR bands of OCH₃ of MMA at 1725 cm^?1 and –C=O of N-VP at 1679 cm^?1, confirms the incorporation of both the monomers in the copolymer. The glass transition temperature of the copolymer is 133°C. The GPC data shows the polydispersity index at about 1.5. The ESR spectroscopy confirm phenyl radical responsible for initiation.     

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     

Photo-induced controlled/living copolymerization of styrene and acrylic acid and determination of reactivity ratios

A controlled/living photopolymerization of styrene (St) and acrylic acid (AA) mediated by FeCl₃·6H₂O/tetramethylethylenediamine (TMEDA) was performed in N,N-dimethylformamide using 4-bromomethylbenzophenon (4-BMBP) as photoinitiator at room temperature under UV irradiation. 4-BMBP was first used as ATRP initiator and photoinitiator. A well-defined poly(styrene-co-acrylic acid) with predetermined molecular weight and narrow molecular weight distribution was obtained. The kinetic rule of controlled free radical photopolymerization of St and AA was studied. The kinetic results showed that the obtained random poly(St-co-AA) copolymers produced narrow polydispersity (PDI) within the range of 1.25–1.32 when the conversion was beyond 16.5 %, which was characterized by GPC. The plots of number average molecular weight versus conversion and ln([M]₀/[M]) versus time were linear, indicating a controlled/living photopolymerization process. The system proceeded under mild and environmentally friendly conditions. The effects of initiator, catalyst, ligand, and vitamin C(VC) concentrations on polymerization process were investigated. The copolymers were characterized by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (¹H NMR). The methods of Mayo-Lewis (ML), Kelen-Tudos (KT), and Yzrielev-Brokhina Roskin (YBR) were used to calculate the monomer reactivity ratios of controlled/living photopolymerization of St and AA at low conversions under selected conditions. The monomer reactivity ratios of St and AA were calculated to be r _St = 0.82 and r _AA = 0.30, respectively in this system. The living characteristics were demonstrated by chain extension experiment.     

Synthesis of imide‐based methacrylic monomers and their copolymerization with methyl methacrylate: monomer reactivity ratios and heat resistance properties

The newly designed methacrylic monomer series 4‐phthalimidocyclohexyl methacrylate (PCMA ), 4‐hexahydrophthalimidocyclohexyl methacrylate (HPCMA) and 4‐hexahydro‐3,6‐methanophthalimidocyclohexyl methacrylate (HMPCMA) were synthesized. Their homopolymers and methyl methacrylate (MMA) based copolymer series were polymerized by free‐radical polymerization. The copolymer compositions were characterized using ¹H NMR spectra. The monomer reactivity ratios were calculated employing the Fineman?Ross (F‐T) and Kelen?Tüdös (K‐T) methods at low conversion. The values of r₁ and r₂ obtained by the F‐T and K‐T methods appear to be in close agreement (their average values are r₁ = 1.3061 and r₂ = 0.7336 for poly(PCMA‐co‐MMA), r₁ = 1.5169 and r₂ = 0.6840 for poly(HPCMA‐co‐MMA), r₁ = 1.7748 and r₂ = 0.5664 for poly(HMPCMA‐co‐MMA)) . The thermal stabilities and thermomechanical characteristics of the homopolymer and copolymer series were investigated by differential scanning calorimetry, thermogravimetric analysis and dynamic mechanical thermal analysis. © 2018 Society of Chemical Industry     

Calculation of reactivity ratios of methacrylic acid-ethyl acrylate copolymer by on-line quantitative 1H NMR spectroscopy

The solution copolymerization of methacrylic acid (MAA) and ethyl acrylate (EA) was studied by online proton nuclear magnetic resonance spectroscopy (¹H NMR) using 2,2′–azobisisobutyronitrile as an initiator in deuterated dimethyl sulfoxide at 60 °C. The chemical compositions of the copolymer and the comonomer concentrations were determined from the conversion of comonomers to copolymer by quantitative in situ NMR monitoring to estimate the reactivity ratios of the comonomers at low conversion. This is a new and easy methodology to analyze radical copolymerization. In this research, it is shown that monomer reactivity ratios can be calculated by data collected only from one initial comonomer mixture composition via online monitoring progress of the copolymerization reaction. The reactivity ratios of MAA and EA are equal to 2.360 and 0.414, respectively. This approach is used to compute the monomer reactivity ratios in a nonlinear integrated form of the copolymerization equation which is described by Mayo and Lewis terminal model. The fairly good agreement between the results and the literature data reported for the emulsion system represent the accuracy of the reactivity ratios calculated by this new approach. The calculated reactivity ratios for emulsion copolymerization are r _MAA = 2.040 and r _EA = 0.470, and the previous literature data are r _MAA = 2.580 and r _EA = 0.157.     

Copolymerization of 4-cyanophenyl methacrylate with methyl methacrylate: Synthesis,characterization and determination of monomer reactivity ratios

Summary A novel methacrylic monomer, 4-cyanophenyl methacrylate (CPM) was synthesized by reacting 4-cyanophenol dissolved in methyl ethyl ketone (MEK) with methacryloyl chloride in the presence of triethylamine as a catalyst. Copolymers of CPM with methyl methacrylate(MMA) at different composition was prepared by free radical solution polymerization at 70±1 °C using benzoyl peroxide as initiator. The copolymers were characterized by FT-IR, ¹H-NMR and ¹³C-NMR spectroscopic techniques. The solubility of the polymers was tested in various polar and non polar solvents. The molecular weight and polydispersity indices of the copolymers were determined using gel permeation chromatography. The glass transition temperature of the copolymers increases with increase in mole fraction of MMA content. The thermal stability of the copolymer increases with increases in mole fraction of CPM content in the copolymer. The copolymer composition was determined by using ¹H-NMR spectroscopy. The monomer reactivity ratios estimated by the application of linearization methods such as Fineman-Ross (r₁=2.524±0.038, r₂=0.502±0.015), Kelen-Tudos (r₁=2.562±0.173, r₂=0.487±0.005) and extended Kelen-Tudos methods (r₁=2.735±0.128, r₂=0.4915±0.007).     

Thermal decomposition of diethyl ketone triperoxide in methyl methacrylate: Theoretical and experimental study of the initial solvation state and its influence on the polymerization process

The decomposition rate constant (k_d) of diethyl ketone triperoxide (DEKTP, 3,3,6,6,9,9‐hexaethyl‐1,2,4,5,7,8‐hexaoxacyclononane) in methyl methacrylate (MMA) was determined by the kinetic study of its thermal decomposition at temperatures from 110 to 140°C. The calculated k_d for DEKTP in MMA was 2.4 times lower (at 130°C) compared with that previously determined and reported in styrene (St). Density functional theory (DFT) calculations demonstrated that the decomposition of DEKTP molecule in MMA required higher interaction energy than in St, thus explaining its lower k_d value. Bulk polymerization kinetics of MMA using DEKTP as the initiator revealed the presence of an induction period, in contrast with St polymerization, providing clear evidence of the solvation state influence at early polymerization stages. This work provides mechanistic insights into the interactions among the multi‐functional cyclic peroxide DEKTP and vinyl monomers; St and MMA, and their influence on the polymerization kinetics. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42905.     

Synthesis,Characterization, Reactivity Ratio and Photo Crosslinking Properties of the Copolymer of 4-Cinnamoyl Phenyl Methacrylate with Butyl Methacrylate

Copolymers of 4-cinnamoyl phenyl methacrylate (4-CPMA) and n-butyl methacrylate (BMA) were prepared in a methyl ethyl ketone (MEK) solution with benzoyl peroxide (BPO) as an initiator at 70°C. They were characterized with UV, IR, ¹H-NMR, ¹³C-NMR, TGA, DSC and gel permeation chromatography. Copolymers were prepared by using different feed ratio of monomers. The monomer reactivity ratios determined by the method of Kelen-Tudos (K-T) were r₁ (CPMA) = 2.32, r₂ (BMA) = 0.56. The glass transition temperature of the copolymer shows a single Tg indicating the formation of random copolymer for all of the monomer feed composition. Thermogravimetric analysis in air has shown that the initial decomposition temperature of the copolymer was above 220°C. The photocrosslinking properties of the copolymer were examined by UV irradiation with polymer film.     

Free radical copolymerization of N,N‐dimethylaminoethyl methacrylate with styrene and methyl methacrylate: monomer reactivity ratios and glass transition temperatures

BACKGROUND: The properties of copolymers depend strongly on their composition; therefore in order to tailor some for specific applications, it is necessary to control their synthesis, and, in particular, to know the reactivity ratios of their constituent monomers. Free radical copolymerizations of N,N‐dimethylaminoethyl methacrylate (DMAEM) with styrene (ST) and methyl methacrylate (MMA) in toluene solution using 1‐di(tert‐butylperoxy)‐3,3,5‐trimethylcyclohexane as initiator at 70 °C were investigated. Monomer reactivity ratios were determined for low conversions using both linear and nonlinear methods. RESULTS: For the DMAEM/ST system the average values are r₁ = 0.43 and r₂ = 1.74; for the DMAEM/MMA system the average values are r₁ = 0.85 and r₂ = 0.86. The initial copolymerization rate, R_p, for DMAEM/ST sharply decreases as the content of ST in the monomer mixture increases up to 30 mol% and then attains a steady value. For the DMAEM/MMA copolymerization system the composition of the feed does not have a significant influence on R_p. The glass transition temperatures (T_g) of the copolymers were determined calorimetrically and calculated using Johnston's sequence length method. A linear dependence of T_g on copolymer composition for both systems is observed: T_g increases with increasing ST or MMA content. CONCLUSION: Copolymerization reactivity ratios enable the design of high‐conversion processes for the production of copolymers of well‐defined properties for particular applications, such as the improvement of rheological properties of lubricating mineral oils. Copyright © 2009 Society of Chemical Industry     

Hydrogels from 2-(dimethylamino)ethylacrylate with 2-acrylamido-2-methyl-1-propanesulfonic acid: synthesis,characterization, and water-sorption properties

A novel series of copolymer hydrogels of 2-(dimethylamino)ethylacrylate (DMAEA)/2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) were prepared by solution free radical polymerization at different feed monomer mol ratios. The monomer reactivity ratios were determined by Kelen–Tüdös method. According to that, the monomer reactivity ratios for poly(DMAEA-co-AMPS) were r₁ = 0.125 and r₂ = 2.85, (r₁ × r₂ = 0.356). The effect of reaction parameters, including the concentration of cross-linking reagent N,N′-methylene-bis-acrylamide (MBA) and initiator ammonium persulfate (APS), the monomer concentration, pH, temperature, salt solutions, and solvent polarity on the water absorption have been also studied. The hydrogels achieved water-absorption values of 430 g of water/g of xerogel for the copolymer 1:2 richest in AMPS moiety. This copolymer is also very stable to the temperature effect. The optimum pH for the copolymers is 7. Aqueous solutions of the copolymers showed lower critical solution temperature behaviour (LCST). The phase transition temperatures of aqueous solutions of these copolymer increased with increasing of hydrophilic AMPS unit content in the copolymers. The glass transition temperature (Tg) of hydrogels showed a decrease by increasing of comonomer DMAEA content.     

Atom transfer radical copolymerization of methyl methacrylate with N‐cyclohexylmaleimide

Atom transfer radical polymerization has been applied to simultaneously copolymerize methyl methacrylate (MMA) and N‐cyclohexylmaleimide (NCMI). Molecular weight behaviour and kinetic study on the copolymerization with the CuBr/bipyridine(bpy) catalyst system in anisole indicate that MMA/NCMI copolymerization behaves in a ‘living’ fashion. The influence of several factors, such as temperature, solvent, initiator and monomer ratio, on the copolymerization were investigated. Copolymerization of MMA and NCMI in the presence of CuBr/bpy using cyclohexanone as a solvent instead of anisole displayed poor control. The monomer reactivity ratios were evaluated as r_NCMI = 0.26 and r_MMA=1.35. The glass transition temperature of the resulting copolymer increases with increasing NCMI concentration. The thermal stability of plexiglass could be improved through copolymerization with NCMI. © 2000 Society of Chemical Industry     

Copolymerization of alkyl α-chloroacrylates with methyl methacrylate

Hexyl α-chloroacrylate (HCA) and cyclohexyl α-chloroacrylate (CCA) have been copolymerized with methyl methacrylate (MMA) in toluene at 55°C using azobisisobutyronitrile (AIBN) as initiator. Copolymer compositions have been determined both by ¹H NMR and elemental analyses. For copolymerization of MMA (M1) with HCA (M2), the reactivity ratios (RR) are r₁ = 0.47 ± 0.19 and r₂ = 0.81 ± 0.51 and with CCA the values are r₁ = 0.76 ± 0.31 and r₂ = 2.30 ± 1.73. Thermal properties of these copolymers have also been investigated.     

Preparation and microwave dielectric properties of BaLi1+xF3+x (x = 0–0.01) ceramics

BaLi_1+xF_3+x (x = 0–0.01) were successfully mechanosynthesized by a simple ball-milling process. The effects of excessive LiF and sintering method and/or annealing atmosphere on its sintering behavior, microstructure, and microwave dielectric properties have been investigated in this paper. The mechanosynthesized powder can be densified with relative densities of ∼95 % after sintering at 750–800 °C/2 h in N₂. The obtained ceramics exhibit excellent optimized microwave dielectric properties with ε_r of ∼11.46 ± 0.06, Q×f values of 83175 ± 1839 GHz and τ_f of ∼ − 70 ± 3 ppm/°C at the x = 0.006 composition. Its Q×f value could be improved to 94603 ± 2037 GHz) by post-annealing in N₂ after post annealing at 700 °C/2 h. The Q×f value could be further improved to (120,098 ± 2344 GHz) by hot-pressed sintering (HPS). Sintering in the ambient atmosphere or O₂ leads to lower Q×f values than those of the counterparts sintered in N₂ due to the introduction of F-vacancies by oxidation_, while little variation in ε_r andτ_f.     

Copolymerization of 2-Ethylhexyl Acrylate and D-Limonene

The bulk free radical copolymerization of D-limonene and 2-ethylhexyl acrylate (EHA) was conducted at 80°C using benzoyl peroxide (BPO) as initiator. Low conversion experiments were conducted to estimate the copolymer reactivity ratios. The reactivity ratios r₁ = 6.896 and r₂ = 0.032 (1 = EHA, 2 = d-limonene) were obtained using a non-linear, error-in-variables method with the RREVM computer program. High conversion experiments were performed and revealed that a degradative chain transfer mechanism for D-limonene dominated the polymerization.