Copolymerization of 2-sulfoethyl methacrylate

Copolymers of 2-sulfoethyl methacrylate, (SEM) were prepared with ethyl methacrylate, ethyl acrylate, vinylidene chloride, and styrene in 1,2-dimethoxyethane solution with N,N′-azobisisobutyronitrile as initiator. The monomer reactivity ratios with SEM (M₁) were: vinylidene chloride, r₁ = 3.6 ± 0.5, r₂ = 0.22 ± 0.03; ethyl acrylate, r₁ = 3.2 ± 0.6, r₂ = 0.30 ± 0.05; ethyl methacrylate, r₁ = 2.0 ± 0.4, r₂ = 1.0 ± 0.1; styrene, r₁ = 0.6 ± 0.2, r₂ = 0.37 ± 0.03. The values of the copolymerization parameters calculated from the monomer reactivity ratios were e = +0.6 and Q = 1.4. Comparison of the monomer reactivities indicates that SEM is similar to ethyl methacrylate with regard to copolymerization reactivity in 1,2-dimethoxyethane solution. The sodium salt of 2-sulfoethyl methacrylate, SEM^?Na^⊕, was copolymerized with 2-hydroxyethyl methacrylate (M₂) in water solution. Reactivity ratios of r₁ = 0.7 ± 0.1 and r₂ = 1.6 ± 0.1 were obtained, indicating a lower reactivity of SEM^?Na^⊕ in water as compared to SEM in 1,2-dimethoxyethane. This decreased reactivity was attributed to greater ionic repulsion between reacting species in the aqueous medium.     

Synthesis of Graft Polymers by Copolymerization of Macromonomers. II. Copolymerization Kinetics of Styrene-and Methacrylate-Terminatedpoly(2-Acetoxyethyl Methacrylate) Macromonomers

Styrene-terminated poly(2-acetoxyethyl methacrylate) macromonomer (EBA), methacrylate-terminated poly(2-acetoxyethyl methacrylate) macromonomer (MPA), and methacrylate-terminated poly(methyl methacrylate) macromonomer (MPM) were synthesized and subjected to polymerization and copolymerization by a free-radical polymerization initiator (AIBN). EBA and MPA were homopolymerized at various concentrations. EBA exhibited higher reactivity than styrene. The reactivity of MPA, however, was almost equal to that of glycidyl methacrylate. Cumulative copolymer compositions were determined by GPC analysis of copolymerization products. The reactivity ratios estimated were r_a = 0.95 and r_b , = 0.90 for EBA macromonomer (a)-methyl methacrylate (b) copolymerization. These values were not consistent with literature values for the styrene-methyl methacrylate and p-methoxy-styrene-methyl methacrylate systems. The reactivity ratios estimated for MPA and 2-bromoethyl methacrylate were r_a - 0.95 and r_b , = 0.98; equal to the glycidyl methacrylate-2-bromoethyl methacrylate system. MPA or MPM was also copolymerized with styrene, and the reactivity ratios were r_a = 0.40, r_a = 0.60 and r_a = 0.39, r_a = 0.58, respectively. These estimates were in good agreement with the reactivity ratios for glycidyl methacrylate and styrene. Thus, no effect of molecular weight was observed for both copolymerization systems.     

Radical Copolymerization of Acrylic Monomers. II Effect of Solvent on Radical Copolymerization of Methyl Methacrylate and Styrene

The influence of various solvents on the copolymerization behavior of methyl methacrylate with styrene has been investigated. In these systems there is a significant solvent effect on both r_S and r_M which may be attributed to changes in the dielectric constant of the solvents used. The calculated relative reactivity of the polystyryl radical towards the methyl methacrylate monomer increases with increasing solvent polarity, whereas the reactivity of poly(methyl methacrylate) radical towards styrene monomer decreases. The results obtained are discussed taking into account the behavior of both monomers in homopolymerization with the same experimental conditions as in copolymerization.     

Anionic copolymerization of optically active α-methylbenzyl methacrylate and trityl methacrylate. I. Reactivity of monomers

The monomer reactivity ratios were determined in the anionic copolymerization of (S)- or (RS)-α-methylbenzyl methacrylate (MBMA) and trityl methacrylate (TrMA) with butyllithium at ?78°C, and the stereoregularity of the yielded copolymer was investigated. In the copolymerization of (S)-MBMA (M₁) and TrMA (M₂) in toluene the monomer reactivity ratios were r₁ = 8.55 and r₂ = 0.005. On the other hand, those in the copolymerization of (RS)-MBMA with TrMA were r₁ = 4.30 and r₂ = 0.03. The copolymer of (S)-MBMA and TrMA prepared in toluene was a mixture of two types of copolymer: one consisted mainly of the (S)-MBMA unit and was highly isotactic and the other contained both monomers copiously. The same monomer reactivity ratios, r₁ = 0.39 and r₂ = 0.33, were obtained in the copolymerizations of the (S)-MBMA–TrMA and (RS)-MBMA–TrMA systems in tetrahydrofuran (THF). The microstructures of poly[(S)-MBMA-co-TrMA] and poly-[(RS)-MBMA-co-TrMA] produced in THF were similar where the isotacticity increased with an increase in the content of the TrMA unit.     

Intramolecular charge transfer complexes. VIII. Poly[N-(2-hydroxyethyl) carbazolyl acrylate-co-2,4-dinitrophenyl methacrylate]

Radical copolymerization of N-(2-hydroxyethyl) carbazolyl acrylate (HECA, M₁) with 2,4-dinitrophenyl methacrylate (DNPM, M₂) can be described by a simple terminal mechanism having the relative reactivities r₁ = 0.14, r₂ = 1.10 (at 60°C); 0.28, 0.96 (80°C); and 0.41, 0.79 (100°C), respectively. The dependence of the reactivity ratio values on copolymerization temperature, analyzed by Arrhenius equation, takes place mainly through the frequency factor. The copolymers obtained are intramolecular charge transfer complexes. The intramolecular interaction is evidenced by the shift of the aromatic protons from the DNPM structural unit in the copolymers' ¹H-NMR (nuclear magnetic resonance) spectra. This shift depends on sequence distribution and chain conformation, but is not affected by the copolymerization temperature.     

Monomer reactivity ratio and Q–e values for copolymerization of hydroxyalkyl acrylates and 2-(1-aziridinyl)ethyl methacrylate with styrene

Copolymers of 2-hydroxyethyl acrylate, hydroxypropyl acrylate, and 2(1-aziridinyl)-ethyl methacrylate (M₂) with styrene (M₁) were prepared in benzene solution at 60°C. Benzoyl peroxide, 0.1–0.2 mole-%, was used as initiator. Copolymer samples with the molar concentrations of M₂ feed ranging from 0.10 to 0.85 were used to determine the reactivity ratios. Elemental analysis and nuclear magnetic resonance spectroscopy (NMR) were used to determine copolymer compositions. There was a solubility problem when the latter technique was applied. When samples which were completely soluble were analyzed, the results obtained from NMR and elemental analysis were in excellent agreement. The monomer reactivity ratios and the corresponding parameters for the copolymerization of (M₁) with 2-hydroxyethyl acrylate are: r₁ = 0.38 ± 0.02, r₂ = 0.34 ± 0.03; Q₂ = 0.85, e₂ = 0.64; with hydroxypropyl acrylate are: r₁ = 0.45 ± 0.03, r₂ = 0.36 ± 0.03; Q₂ = 0.75, e₂ = 0.56; with 2(1-aziridinyl)ethyl methacrylate are: r₁ = 0.53 ± 0.02, r₂ = 0.63 ± 0.04; Q₂ = 0.82, e₂ = 0.25.     

Effect of solvent on the copolymerization of ethylene and vinyl acetate

The ethylene (M₁)–vinyl acetate (M₂) copolymerization at 62°C and 35 kg/cm² with α,α′-azo-bisisobutyronitrile as initiator has been studied in four different solvents, viz., tert-butyl alcohol, isopropyl alcohol, benzene, and N,N-dimethylformamide. The experimental method used was based on frequent measurement of the composition of the reaction mixture throughout the copolymerization reaction by means of quantitative gas chromatographic analysis. Highly accurate monomer reactivity ratios have been calculated by means of the curve-fitting I procedure. The observed dependence of the r values on the nature of the solvent is surprisingly large and can be correlated with the volume changes (= excess volumes) observed on mixing vinyl acetate (VAc) with the relevant solvent. An increased hydrogen bonding or dipole–dipole interaction through the carbonyl moiety of the acetate side group of VAc, induces a decreased electron density on the vinyl group of VAc, which in turn leads to a decreased VAc reactivity. The differences among the overall rates of copolymerization in the various solvents can be interpreted in terms of a variable chain transfer to solvent and the rate of the subsequent reinitiation by the solvent radical. In the case of benzene, complex formation is believed to play an important part.     

Radical polymerization of new functional monomer: Methacryloyl isocyanate containing 4‐chloro‐1‐phenol

New functional monomer methacryloyl isocyanate containing 4‐chloro‐1‐phenol (CPHMAI) was prepared on reaction of methacryloyl isocyanate (MAI) with 4‐chloro‐1‐phenol (CPH) at low temperature and was characterized with IR, ¹H, and ¹³C‐NMR spectra. Radical polymerization of CPHMAI was studied in terms of the rate of polymerization, solvent effect, copolymerization, and thermal properties. The rate of polymerization of CPHMAI has been found to be smaller than that of styrene under the same conditions. Polar solvents such as dimethylsulfoxide (DMSO) and N,N‐dimethyl formamide (DMF) were found to slow the polymerization. Copolymerization of CPHMAI (M₁) with styrene (M₂) in tetrahydrofuran (THF) was studied at 60°C. The monomer reactivity ratio was calculated to be r₁ = 0.49 and r₂ = 0.66 according to the method of Fineman—Ross. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 469–473, 2000     

Copolymerization of optically active N-bornylmaleimide with vinyl monomers

Optically active N-bornylmaleimide (NBMI) was copolymerized with styrene, methyl methacrylate, and vinylidene chloride with a free-radical catalyst to obtain optically active copolymers. The monomer reactivity ratios for the radical copolymerization of NBMI (M₂) with styrene, methyl methacrylate, and vinylidene chloride were: ST-NBMI, r₁ = 0.13, r₂ = 0.05; MMA-NBMI, r₁ = 2.02, r₂ = 0.16; VCl₂-NBMI, r₁ = 1.15, r₂ = 0.47. The Q-e values for NBMI were Q₂ = 0.48 and e₂ = +1.47. The specific rotation and optical rotatory dispersion of these copolymers were measured. The correlation between the specific rotation and composition of these copolymers was not linear. The value of λ_c for each copolymer was independent of the copolymer composition and the comonomer, being 260 mμ for the St-NBMI system, 262 mμ for the MMA-system, and 260 mμ for the VCl₂-NBMI system. The effects of solvents and temperature on the specific rotation of these copolymers were investigated.     

Photosensitized copolymerization of optically active N-l-menthylmaleimide with styrene and methyl methacrylate

Photosensitized copolymerization of optically active N-l-menthylmaleimide (NMMI) with styrene (Sty) and methyl methacrylate (MMA) was carried out in tetrahydrofuran (THF) at 30°C with benzoyl peroxide (BPO). The monomer reactivity ratios for the copolymerization of NMMI (M₂) with Sty (M₁) and MMA (M₁) were r₁ = 0.08 ± 0.10, r₂ = 0.20 ± 0.05 and r₁ = 2.85 ± 0.06, r₂ = 0.07 ± 0.06, respectively. Copoly-MMA–NMMI and poly-NMMI showed positive circular dichroism(CD) curves of equal intensity and shape over the wavelength region from 230 to 270 nm; copoly-Sty–NMMI also showed a positive CD curve which was similar in shape but was different in intensity from that of poly-NMMI. The correlation between monomer unit ellipticity of the copolymers and their composition would suggest the alternating and stereoregular copolymerization of NMMI with Sty.     

Aminimides. V. Preparation and polymerization studies of trimethylamine-4-vinylbenzimide

Trimethylamine-4-vinylbenzimide (TAVBI) has been homo- and copolymerized with styrene, methyl methacrylate, and hydroxypropyl methacrylate by free-radical initiators to soluble, low molecular weight polymers containing pendant aminimide groups along the backbone of the polymer molecules. The reactivity ratios in the copolymerization of TAVBI (M₁) with styrene (M₂) were determined: r₁ = 0.63 ± 0.07, r₂ = 0.47 ± 0.05. The Alfrey-Price Q and e values for TAVBI were also calculated: Q = 0.88, e = 0.31. This introductory work indicates that TAVBI has potential for the preparation of a wide variety of reactive polymers.     

Reactivity ratios in conventional and nickel-mediated radical copolymerization of methyl methacrylate and functionalized methacrylate monomers

Copolymerization of an excess of methyl methacrylate (MMA) relative to 2-hydroxyethyl methacrylate (HEMA) was carried out in toluene at 80 °C according to both conventional and controlled Ni-mediated radical polymerizations. Reactivity ratios were derived from the copolymerization kinetics using the Jaacks method for MMA and integrated conversion equation for HEMA (r_MMA = 0.62 ± 0.04; r_HEMA = 2.03 ± 0.74). Poly(ethylene glycol) α-methyl ether, ω-methacrylate (PEGMA, M_n = 475 g mol⁻¹) was substituted for HEMA in the copolymerization experiments and reactivity ratios were also determined (r_MMA = 0.75 ± 0.07; r_PEGMA ∼ 1.33). Both the functionalized comonomers were consumed more rapidly than MMA indicating the preferred formation of heterogeneous bottle-brush copolymer structures with bristles constituted by the hydrophilic (macro)monomers. Reactivity ratios for nickel-mediated living radical polymerization were comparable with those obtained by conventional free radical copolymerization. Interactions between functional monomers and the catalyst (NiBr₂(PPh₃)₂) were observed by ¹H NMR spectroscopy.     

Copolymerization of styrene and methyl methacrylate. Reactivity ratios from conversion–composition data

A method for the determination of reactivity ratios from conversion–composition data has been outlined. The conversion–composition changes during the copolymerization of styrene (M₁) and methyl methacrylate (M₂) have been studied at 60°C. By a method of graphical intersection, the integrated form of Skeist's equation has been used to determine the reactivity ratios (r₁ = 0.54 ± 0.02 and r₂ = 0.50 ± 0.06) in reasonably good agreement with values reported in the literature. The area of intersection was used as a measure of the precision of the data.     

Radical polymerization of N-phenyl-α-methylene-β-lactam

N-phenyl-α-methylene-β-lactam (PML), a cyclic analog of N,N-disubstituted methacrylamides which do not undergo radical homopolymerization, was synthesized and polymerized with α,α′-azobis (isobutyronitrile) (AIBN) in solution. Poly (PML) (PPML) is readily soluble in tetrahydrofuran, chloroform, pyridine, and polar aprotic solvents but insoluble in toluene, ethyl acetate, and methanol. PPML obtained by radical initiation is highly syndiotactic (rr = 92%), exhibits a glass transition at 180°C, and loses no weight upto 330°C in nitrogen. The kinetics of PML homo-polymerization with AIBN was investigated in N-methyl-2-pyrrolidone. The rate of polymerization (R_p) can be expressed by R_p = k[AIBN]^0.55[PML]^1.2 and the overall activation energy has been calculated to be 87.3 kJ/mol. Monomer reactivity ratios in copolymerization of PML (M₂) with styrene (M₁) are r₁ = 0.67 and r₂ = 0.41, from which Q and e values of PML are calculated as 0.60 and 0.33, respectively.     

Synthesis of substituted polymethylenes by radical polymerization of N,N,N′,N′-tetraalkylfumaramides and their characterization

Radical polymerization of N,N,N′,N′-tetraalkylfumaramides (TRFAm) bearing methyl, ethyl, n-propyl, isopropyl, and isobutyl groups as N-substituents (TMFAm, TEFAm, TnPFAm, TIPFAm, and TIBFAm, respectively) was investigated. In the polymerization of TEFAm initiated with 1,1′-azobiscyclohexane-1-carbonitrile (ACN) in benzene, the polymerization rate (R_p) was expressed as follows: R_p = k [ACN]^0.28 [TEFAm]^1.26, and the overall activation energy was 102.1 kJ/mol. The introduction of a bulky alkyl group into N-substituent of TRFAm decreased the R_p in the following order: TMFAm > TEFAm > TnPFAm > TIBFAm > TIPFAm ～ 0. The relative reactivities of these monomers were also investigated in radical copolymerization with styrene (St) and methyl methacrylate (MMA). In copolymerization of TRFAm (M₂) with St (M₁), monomer reactivity ratios were determined to be r₁ = 1.07 and r₂ = 0.20 for St–TMFAm, and r₁ = 1.88 and r₂ = 0.11 for St–TEFAm, from which Q₂ and e₂ values were estimated to be 0.35 and 0.44 for TMFAm, and 0.19 and 0.47 for TEFAm, respectively. The other TRFAm were also copolymerized with St, but copolymerization with MMA gave polymers containing a small amount of TRFAm units. The polymer from TRFAm consists of a less-flexible poly(N,N-dialkylaminocarbonylmethylene) structure. The solubility and thermal property of the polymers were also investigated.     

Copolymers of 2-hydroxyethyl methacrylate and alkyl methacrylates. I. Synthesis and characterization

Copolymerization of 2-hydroxyethyl methacrylate (HEMA) with ethyl methacrylate (EMA) and n-butyl methacrylate (BMA) was carried out in bulk at 70°C ± 1°C using 0.2% benzoyl peroxide as initiator in nitrogen atmosphere. Number average molecular weight (M _n) of the copolymers was determined by dynamic osmometry. Intrinsic viscosity [η] of HEMA-BMA copolymers was evaluated at 35°C in dimethyl formamide. These copolymers were also characterized by infrared spectroscopy and density measurements. Cohesive energy densities (CED) of these polymers were determined by observing their swelling behavior in different solvents. It was found that a decrease in alkyl methacrylate content resulted in an increase in the CED values of the copolymers.     

Quantitative Determination of the Contribution of Charge‐Transfer Complex in the Microemulsion Copolymerization of N‐Butyl Maleimide and Styrene

By using sodium dodecyl sulfate (SDS) and pentanol (PTL) as emulsifiers, the oil‐in‐water microemulsion containing N‐butyl maleimide (NBMI, M₁) and styrene (St, M₂) was prepared. The microemulsion copolymerization using potassium persulfate (KPS) as an initiator was investigated. On the basis of kinetic model proposed by SHAN Guo‐Rong, the reactivity ratios of free monomers and the charge‐transfer complex (CTC) in the copolymerization were found to be r₁₂ = 0.0420, r₂₁ = 0.0644, r_1C = 0.00576 and r_2C = 0.00785, respectively. A kinetic treatment based on this model was used to quantitatively estimate the contribution of CTC to the total copolymerization rate in the NBMI/St copolymerization. It was about 17.0–20.0% for a wide range of monomer feed ratios.     

Free-radical homopolymerization and copolymerization of vinylferrocene

The benzene solution homopolymerization of vinylferrocene, initiated by azobisisobutyronitrile, gave a series of benzene-soluble homopolymers. Thus, free-radical copolymerization studies were performed with styrene, methyl acrylate, methyl methacrylate, acrylonitrile, vinyl acetate, and isoprene in benzene. With the exception of vinyl acetate and isoprene, which did not give copolymers with vinylferrocene under these conditions, smooth production of copolymers occurred. The relative reactivity ratios, r₁ and r₂, were obtained for vinylferrocene–styrene copolymerizations by using the curve-fitting method for the differential form of the copolymer equation, by the Fineman-Ross technique, and by computer fitting of the integrated form of the copolymer equations applied to higher conversion copolymerizations. In styrene (M₂) copolymerizations, the curve-fitting and Fineman-Ross methods both gave r₁ = 0.08, r₂ = 2.50, while the integration method gave r₁ = 0.097, r₂ = 2.91. Application of the integration method to methyl acrylate and methyl methacrylate (M₂) gave values of r₁ = 0.82, r₂ = 0.63; r₁ = 0.52, r₂ = 1.22, respectively. The curve-fitting method gave r₁ = 0.15, r₂ = 0.16 for acrylonitrile (M₂) copolymerizations. From styrene copolymerizations, vinylferrocene exhibited values of Q = 0.145 and e = 0.47.     

Vinylhydroquinone. III. Copolymerization of vinylhydroquinone and vinyl monomers by tri-n-butylborane

The copolymerization of vinylhydroquinone (VHQ) and vinyl monomers, e.g., methyl methacrylate (MMA), 4-vinyl-pyridine (4VP), acrylamide (AA), and vinyl acetate (VAc), by tri-n-butylborane (TBB) was investigated in cyclohexanone at 30°C under nitrogen. VHQ is assumed to copolymerize with MMA, 4VP, and AA by vinyl polymerization. The following monomer reactivity ratios were obtained (VHQ = M₂): for MMA/VHQ/TBB, r₁ = 0.62, r₂ = 0.17; for 4VP/VHQ/TBB, r₁ = 0.57, r₂ = 0.05; for AA/VHQ/TBB, r₁ = 0.35, r₂ = 0.08. The Q and e values of VHQ were estimated on the basis of these reactivity ratios as Q = 1.4 and e = ?;1.1, which are similar to those of styrene. This suggests that VHQ behaves like styrene rather than as an inhibitor in the TBB-initiated copolymerization. No homopolymerization was observed either under nitrogen or in the presence of oxygen. The reaction mechanism is discussed.