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.     

Synthesis and characterization of methyl methacrylate/styrene hyperbranched copolymers via living radical mechanism

Free‐radical copolymerizations of N,N‐diethylaminodithiocarbamoylmethylstyrene (inimer: DTCS) with a methyl methacrylate (MMA)/zinc chloride (ZnCl₂) complex were carried out under UV light irradiation. DTCS monomers play an important role in this copolymerization system as an inimer that is capable of initiating living radical polymerization of the vinyl group. The reactivity ratios (r₁ = 0.56 and r₂ = 0.52: DTCS [M₁]; MMA [M₂]) obtained for this copolymerization system were different from a corresponding model system (alternating copolymer) of a styrene and MMA/ZnCl₂ complex (r₁ = 0.25 and r₂ = 0.056). It was found that the hyperbranched copolymers produced exhibited a random branching structure. It was found that the Lewis acid ZnCl₂ formed the complex not only with MMA but also with the carbamate group of inimer. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2490–2495, 2003     

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     

Radical polymerization of new functional monomers: Mono- and dimethacryloyl isocyanate containing bisphenol-A and its derivatives

New functional monomers mono-and dimethacryloyl isocyanate containing bisphenol-A were prepared on reaction of methacryloyl isocyanate (MAI) with bisphenol-A (BPA) and its derivatives at low temperature. The monomers thus obtained were characterized with IR, UV, and ¹H- and ¹³C-NMR spectra. Radical polymerization of mono-and dimethacryloyl isocyanate containing bisphenol-A and its derivatives was studied in terms of the rate of polymerization, solvent effect, copolymerization, thermal properties, and kinetic measurements of photocrosslinking. Polar solvents such as DMSO and NMP were found to slow the polymerization. Copolymerization of BPA-MAI (M₁) with MMA (M₂) in DMF was studied at 90°C. The monomer reactivity ratio was calculated to be r₁ = 0.17 and r₂ = 1.34 according to the method of Fineman–Ross. Functional polymers containing the allyl group were successfully modified and photocrosslinked on irradiation in the presence of benzoin isopropyl ether. The photocrosslinking process follows second-order kinetics. © 1996 John Wiley & Sons, Inc.     

Radical polymerization of mono- and di-methacrylic esters containing bisphenol-S

Radical polymerizations of mono- and di-methacrylic esters containing bisphenol-S (BPS-M and BPS-DM) were studied in terms of polymerization rate, solvent effect, copolymerization and kinetic measurements of photocrosslinking. The solvents were found to affect significantly the polymerization rate. Polar solvents such as DMSO and acetonitrile were found to slow down the polymerization rate. Copolymerization of BPS-M(M₁) with MMA(M₂) was studied in acetone at 60°C. The monomer reactivity ratios were calculated to be r₁ = 3.72 ± 0.01 and r₂ = 0.80 ± 0.01 by the Fineman-Ross method. The high reactivity of BPS-M observed in this copolymerization system may be due to the “matrix effect”. Functional polymers containing methacrylate side-groups were successfully modified and photocrosslinked by irradiation in the presence of benzoin isopropyl ether. The photocrosslinking process is found to be of second order kinetics.     

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     

Reactivity ratios and copolymer properties of 2‐(diisopropylamino)ethyl methacrylate with methyl methacrylate and styrene

Free radical copolymerization kinetics of 2‐(diisopropylamino)ethyl methacrylate (DPA) with styrene (ST) or methyl methacrylate (MMA) was investigated and the corresponding copolymers obtained were characterized. Polymerization was performed using tert‐butylperoxy‐2‐ethylhexanoate (0.01 mol dm^?3) as initiator, isothermally (70 °C) to low conversions (<10 wt%) in a wide range of copolymer compositions (10 mol% steps). The reactivity ratios of the monomers were calculated using linear Kelen–Tüd?s (KT) and nonlinear Tidwell–Mortimer (TM) methods. The reactivity ratios for MMA/DPA were found to be r₁ = 0.99 and r₂ = 1.00 (KT), r₁ = 0.99 and r₂ = 1.03 (TM); for the ST/DPA system r₁ = 2.74, r₂ = 0.54 (KT) and r₁ = 2.48, r₂ = 0.49 (TM). It can be concluded that copolymerization of MMA with DPA is ideal while copolymerization of ST with DPA has a small but noticeable tendency for block copolymer building. The probabilities for formations of dyad and triad monomer sequences dependent on monomer compositions were calculated from the obtained reactivity ratios. The molar mass distribution, thermal stability and glass transition temperatures of synthesized copolymers were determined. Hydrophobicity of copolymers depending on the composition was determined using contact angle measurements, decreasing from hydrophobic polystyrene and poly(methyl methacrylate) to hydrophilic DPA. Copolymerization reactivity ratios are crucial for the control of copolymer structural properties and conversion heterogeneity that greatly influence the applications of copolymers as rheology modifiers of lubricating oils or in drug delivery systems. © 2015 Society of Chemical Industry     

Spreadsheets in copolymerization studies

A Lotus spreadsheet (LS) was utilized as part of a copolymerization study of methyl methacrylate (MMA) with N-phenylmaleimide (MP) and with some derivatives of MP, namely N-o-chlorophenylmaleimide (MOCP), N-p-tolylmaleimide (MPT), and N-o-tolylmaleimide (MOT). The use of LS provided a very rapid method to obtain values of copolymerization parameters which were in very good agreement with non-spreadsheet reported values. Further, a novel LS macro was developed which could be employed to ascertain the shape of the copolymer composition curve (copolymer composition as a function of monomer composition). Monomer reactivity ratios, r₁ and r₂, were determined as well as values of semi-empirical copolymerization parameters Q and e. An attempt was made to correlate the monomer structures used with the values of Q and e. An empirical decomposition temperature index (DTI) was also devised to measure the thermal stability of copolymers of MMA and MP as a function of MP content. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 891–900, 1997     

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.     

Synthesis and characterization of perfluorinated acrylate–methyl methacrylate copolymers

A novel perfluorinated acrylic monomer 3,5‐bis(perfluorobenzyloxy)benzyl acrylate (FM) with perfluorinated aromatic units was synthesized with 3,5‐bis(perfluorobenzyl)oxybenzyl alcohol, acryloyl chloride, and triethylamine. Copolymers of FM monomer with methyl methacrylate (MMA) were prepared via free‐radical polymerization at 80°C in toluene with 2,2′‐azobisisobutyronitrile as the initiator. The obtained copolymers were characterized by ¹H‐NMR and gel permeation chromatography. The monomer reactivity ratios for the monomer pair were calculated with the extended Kelen–Tüdos method. The reactivity ratios were found to be r₁ = 0.38 for FM, r₂ = 1.11 for MMA, and r₁r₂ < 1 for the pair FM–MMA. This shows that the system proceeded as random copolymerization. The thermal behavior of the copolymers was investigated by thermogravimetric analysis and differential scanning calorimetry (DSC). The copolymers had only one glass‐transition temperature, which changed from 46 to 78°C depending on the copolymer composition. Melting endotherms were not observed in the DSC traces; this indicated that all of the copolymers were completely amorphous. Copolymer films were prepared by spin coating, and contact angle measurements of water and ethylene glycol on the films indicated a high degree of hydrophobicity. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Polymerization of methyl methacrylate with metal acetylacetonates and triethylaluminum catalysts

Polymerization of methyl methacrylate (MMA) with metal acetylacetonates, especially vanadium (III) acetylacetonate [V(acac)₃], in combination with AIEt₃ was studied. V(acac)₃–AIEt₃ catalyst could initiate the polymerization of MMA, although other Mt(acac)_xs are also effective. It was found that the polymerization of MMA with V(acac)₃–AIEt₃ catalyst proceeded through a coordination mechanism, from the results of copolymerization with styrene and polymerization in the presence of radical inhibitors. The resulting polymers were found to form stereocomplexes in acetone. Based on these results, it is concluded that multi-active sites in the polymerization of MMA with V(acac)₃–AIEt₃ catalyst were produced.     

Copolymerization of N‐aryl substituted itaconimide with methyl methacrylate: Effect of substituents on monomer reactivity ratio and thermal behavior

The article describes the synthesis and characterization of N‐(4‐methoxy‐3‐chlorophenyl) itaconimide (MCPI) and N‐(2‐methoxy‐5‐chlorophenyl) itaconimide (OMCPI) obtained by reacting itaconic anhydride with 4‐methoxy‐3‐chloroanisidine and 2‐methoxy‐5‐chloroanisidine, respectively. Structural and thermal characterization of MCPI and OMCPI monomers was done by using ¹H NMR, FTIR, and differential scanning calorimetry (DSC). Copolymerization of MCPI or OMCPI with methyl methacrylate (MMA) in solution was carried out at 60°C using AIBN as an initiator and THF as solvent. Feed compositions having varying mole fractions of MCPI and OMCPI ranging from 0.1 to 0.5 were taken to prepare copolymers. Copolymerizations were terminated at low percentage conversion. Structural characterization of copolymers was done by FTIR, ¹H NMR, and elemental analysis and percent nitrogen content was used to calculate the copolymer composition. The monomer reactivity ratios for MMA–MCPI copolymers were found to be r₁ (MMA) = 0.32 ± 0.03 and r₂ (MCPI) = 1.54 ± 0.05 and that for MMA–OMCPI copolymers were r₁ (MMA) = 0.15 ± 0.02 and r₂ (OMCPI) = 1.23 ± 0.18. The intrinsic viscosity [η] of the copolymers decreased with increasing mole fraction of MCPI/or OMCPI. The glass transition temperature as determined from DSC scans was found to increase with increasing amounts of OMPCI in copolymers. A significant improvement in the char yield as determined by thermogravimetry was observed upon copolymerization. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2391–2398, 2006     

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     

Copolymerization of methyl methacrylate with 4‐vinylpyridine initiated by a novel Ni(II)α‐Benzoinoxime complex

Copolymerizations of methyl methacrylate (MMA) with 4‐vinylpyridine (4VP) were performed from different monomer feed ratios in 1,4‐dioxan at 30°C under free radical initiation experimental conditions, using Ni(II)α‐Benzoinoxime complex as initiator. The obtained copolymers (PMMA4VP) were examined by FTIR and ¹H NMR spectroscopies. The composition of these copolymers was calculated, using ¹H NMR spectra and elemental analysis. Monomer reactivity ratios were estimated from Fineman–Ross (FR, r_m = 0.550, r_v = 1.165) and Kelen–Tudos (KT, r_m = 0.559, r_v = 1.286) linearization methods, as well as nonlinear error in variables model (EVM) method using the RREVM computer program (RREVM, r_m = 0.559, r_v = 1.264). These values suggest that MMA‐4VP pair copolymerizes randomly. ¹H NMR spectra provide information about the stereochemistry of the copolymers in terms of sequence distributions and configurations. These results showed that the age of the Ni complex has an impact not only on its activity towards polymerization reactions but also on the features of the corresponding copolymers, whereas the chemical composition was insensitive to this prominent factor. The mechanism of MMA‐4VP copolymerization is consistent with a radical process as supported by microstructure and molecular weight distribution studies. Thermal behaviours of these copolymers were investigated by differential scanning calorimetry and thermogravimetric analysis. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

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     

P[CF3(CF2)5CH2MA‐co‐MMA] and P[CF3(CF2)5CH2MA‐co‐BA] copolymers: Reactivity ratios and surface properties

This study aimed at reducing the surface energy of coatings by copolymerization of commonly used monomers with fluorine‐containing monomers. Copolymers of 1,1‐dihydroperfluoroheptyl methacrylate (FHMA) and methyl methacrylate (MMA) or butyl acrylate (BA) are prepared by low‐conversion polymerization in solution. Using ¹H‐NMR data and nonlinear least‐squares data fitting, reactivity ratios of these systems at 80°C are determined to be r_FHMA = 1.31, r_MMA = 0.76, and r_FHMA = 3.15, r_BA = 0.38, respectively. We assume that the penultimate unit effect plays an important role in these systems. Introduction of the perfluoroalkyl side chain lowers the polymer surface energy significantly; copolymers of MMA and FHMA show a reduction in total surface energy of about 50 % at a content of 15 mol % FHMA as compared with pure PMMA. The attainable reduction in surface energy is much larger than with, for example, Teflon. This is due to the preferential adsorption of the —CF₃ groups of the fluoroalkyl side chain, if compared to that of the —CF₂— groups of Teflon. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 159–165, 2001     

Radical copolymerization between methyl methacrylate and N‐cyclohexylmaleimide with thiol as an inifer

N‐dodecanethiol (RSH) was found efficient to initiate the radical copolymerization of methyl methacrylate (MMA) with N‐cyclohexylmaleimide (NCMI) at 40–60°C. The initial copolymerization rate, R_p, increases respectively with increasing [RSH] and the mol fraction of NCMI in the comonomer feed, f_NCMI. The molecular weight of the copolymer decreases with increasing [RSH]. The initiator transfer constant of RSH was determined to be C_I = 0.21. The apparent activation energy of the overall copolymerization was measured to be 46.9 kJ/mol. The monomer reactivity ratios were determined to be r_NCMI = 0.32 and r_MMA = 1.35. The glass transition temperature of the copolymer increases obviously with increasing f_NCMI, which indicates that adding NCMI may improve the heat resistance of plexiglass. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 74: 1417–1423, 1999     

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.     

A comparison of composition and sequence distribution of p(AM-MADQUAT) prepared by solution and inverse microemulsion polymerization

Acrylamide (AM)/2-(methacryloyloxy)ethyltrimethylammonium chloride (MADQUAT) copolymers were prepared by solution and inverse microemulsion polymerization using ammonium persulfate ((NH₄)₂S₂O₈)/sodium hydrosulfite (NaHSO₃) as redox initiator at 30 °C. The comonomer reactivity ratios, determined using the Kelen–Tudos (KT) method, were r _A = 0.30, r _M = 1.31 in solution and r _A = 0.63, r _M = 1.13 in the inverse microemulsion, respectively. The copolymer microstructure was deduced from the run number and the heterogeneity, based on reactivity ratios. It was found that copolymerization in the inverse microemulsion resulted in close to ideal copolymerization, giving almost random copolymers; copolymerization in solution resulted in some alternating copolymers. The copolymer compositions indicated that high-conversion samples obtained from the inverse microemulsion are much more homogeneous in composition compared with those obtained in solution. It was found that the composition distribution of the copolymer prepared by inverse microemulsion polymerization remained at approximately the feed ratio. The sequence distribution of the copolymer was predicted by first-order Markov statistical and Bernoulli statistical models, respectively. The results showed that the sequence distribution of the copolymer prepared by inverse microemulsion polymerization was almost random, which led to a wider cationic charge distribution and a microstructure that was coincident with the feed ratio.     

Radiation-induced copolymerization of α,β,β-trifluoroacrylonitrile with α-olefin

Homopolymerization and copolymerization of α,β,β-trifluoroacrylonitrile (FAN) with γ-olefins were carried out in bulk by γ-ray irradiation at 25°C. FAN gives very small quantities of brown and greasy low molecular weight polymer. Cyano groups in FAN polymer were found to be readily hydrolyzed to acid amide groups in the atmosphere. FAN was found to copolymerize with ethylene, propylene, and isobutylene via a radical mechanism to form equimolar copolymers in a wide range of monomer compositions. The polymerization rate increases linearly with FAN fraction in the monomer mixture. These copolymers are also hydrolyzed in the atmosphere, and the hydrolysis proceeds with more difficulty for the copolymer with higher α-olefin. The reactivity ratios r₁ (FAN) and r₂ (α-olefin) were determined to be 0.01 and 0.12 for the FAN/ethylene copolymerization and 0.01 and 0.07 for the FAN/propylene copolymerization. These results confirm that an alternating copolymerization takes place in the FAN/α-olefin system.