Studies of the polymerization of diallyl compounds. XXXVII. Copolymerizations of diallyl phthalate with dialkyl fumarates

Diallyl phthalate (DAP) was copolymerized with dialkyl fumarates, including diethyl fumarate (DEF), di-n-butyl fumarate (DBF), and di-n-octyl fumarate (DOF) by using 2,2′-azobisisobutyronitrile as an initiator at 60°C. Both rate and degree of copolymerization were quite enhanced compared with the homopolymerization of DAP and the maximum rate was found at the molar ratio of 1:1 in the monomer feed. The cyclization of DAP was almost exclusively suppressed in the Copolymerization. Gelation was promoted from 25% of the gel-point conversion for the DAP homopolymerization to 9% of the minimum one observed. Copolymerizability of DAP (M₁) with dialkyl fumarates (M₂) was quite high, with the following monomer reactivity ratios M₂, r₁, r₂: DEF, 0.01, 1.25; DBF, 0.02, 1.01; DOF, 0.02, 0.96. These results are discussed in mechanistic detail.     

Copolymerization of isopropenyl and isopropylidene oxazolones with styrene

2-Isopropenyl-4-isopropyl-2-oxazolin-5-one (M₂), was copolymerized with styrene (M₁), and the monomer reactivity ratios were determined to be r₁ = 0.31 ± 0.03, r₂ = 1.12 ± 0.10. New isomerized oxazolones (M₂), 2-isopropylidene-4-methyl-3-oxazolin-5-one, 2-isopropylidene-4-isopropyl-3-oxazolin-5-one, and 2-isopropylidene-4-isobutyl-3-oxazolin-5-one were prepared and copolymerized with styrene. The monomer reactivity ratios were: r₁ = 0.36 = 0.07, r₂ = 0.0; r₁ = 0.39 ± 0.06, r₂ = 0.00 ± 0.10; r₁ = 0.39 ± 0.10, r₂ = 0.0, respectively. The isomerized oxazolones showed no tendency towards homopolymerization by radical initiator. From the results of infrared and NMR spectra and hydrolysis of the copolymer, it was indicated that the isomerized oxazolones participated in copolymerization in the form of 1–4 polymerization of the conjugated dienes (exo double bond at C₂ and the C?N in the ring). Copolymers reacted with nucleophilic reagents such as amines and alcohols.     

Vinylhydroquinone. IV. Preparation and polymerization behavior of 2-methyl-5-vinylhydroquinone derivatives

As in the case of vinylhydroquinone (I), its alkyl-substituted derivative, 2-methyl-5-vinylhydroquinone (II) was found to copolymerize with methyl methacrylate by tri-n-butylborane in cyclohexanone at 30°C. II was prepared from the O,O′-bisether compound, 2-methyl-5-vinyl-O,O′-bis(1′-ethoxyethyl)hydroquinone (III). The monomer reactivity ratios (M₂ = II) were determined to be r₁ = 0.37 and r₂ = 0. No homopolymerization proceeded under the same conditions. Ordinary free-radical initiators, such as azobisisobutyronitrile and benzoyl peroxide, were not effective in the homopolymerization of II. 1:1 Copolymers were obtained from II and maleic anhydride by using tri-n-butylborane as an initiator. The copolymers exhibited no definite melting range and decomposed at 370–375°C endothermally (DSC). The polymerization behavior of III was also investigated. Although tri-n-butylborane did not initiate the homopolymerization of the monomer, azobisisobutyronitrile was capable of initiating the homopolymerization and copolymerization of III. The monomer reactivity ratios (M₁ = styrene) were determined to be r₁ = 0.83 and r₂ = 0.18. The ratios gave the following Q and e values; Q = 0.15 and e = ?2.2.     

Molecular structure of hexafluorobicyclo [2.2.0]hexa-2,5-diene (hexafluoro-dewar-benzene) in the vapour phase

Hexafluoro-Dewar-benzene has been studied by the electron-diffraction method. A model with C_2v symmetry gives excellent agreement between experimental and theoretical data. The structural parameters with error limits are (cf. Fig. 1): r(C₁-C₄)= 1.598 ±0.017 Å, r(C₁-C₂) = 1.505 ±0.005 Å, r(C₂-C₃) = 1.366 ± 0.015 Å, r(C₁-F₁) = 1.328±0.015 Å, r(C₂-F₂) = 1.319±0.007 Å, ∠F₁C₁C₄ = 118.7±0.7°, ∠F₂C₂C₃ = 133.6±0.7°, τ= 121.8±2.0°, and δ = -7.5±2.0°. Molecular orbital calculations by the CNDO/2 method gave τ = 119.8° and δ = ?4.2°.     

Quantum wave packet and quasiclassical trajectory studies of the reaction H(2S) + CH(X2Π; v = 0, j = 1) → C(1D) + H2(X1 ): Coriolis coupling effects and stereodynamics

The quantum mechanics (QM) and quasiclassical trajectory (QCT) calculations have been carried out for the title reaction with the ground minimal allowed rotational state of CH (j = 1) on the 1 ¹A′ potential energy surface. For the reaction probability at total angular momentum J = 0, a similar trend of the QM and QCT calculations is observed, and the QM results are larger than the latter almost in the whole considered energy range (0.1–1.5 eV). The QCT integral cross sections are larger than the QM results with centrifugal sudden approximation, while smaller than those from QM method including Coriolis coupling for collision energies bigger than 0.25 eV. The quantum wave‐packet computations show that the Coriolis coupling effects get more and more pronounced with increasing of J. In addition to the scalar properties, the stereodynamical properties, such as the average rotational alignment factor <P₂( j′?k )>, the angular distributions P(θ_r), P(?_r), P(θ_r,?_r), and the polarization‐dependent generalized differential cross sections have been explored in detail by QCT approach. © 2013 Wiley Periodicals, Inc.     

An alternating copolymer of maleimide and atropic acid with narrow molecular weight distribution prepared by radical mechanism

Three basic conditions for preparation of alternating copolymer with narrow molecular weight distribution were derived from the element kinetic equations of binary radical copolymerization. Using maleimide (MI) and atropie acid (ATA) as model monomer pairs and dioxane as the solvent the alternating copolymer with molecular weight distribution in the range of 1.09--1.20 was prepared successfully by charger transfer complex (CTC) mechanism in the presence of benzoyl peroxide at 85℃. The monomer reactivity ratioes r_1(MI)=0.05±0.01 and r_2(ATA)=0.03±0.02 were measured. The alternating eopolymerization was carried out through formation of a contact-type CTG and then alternating addition of MI and ATA monomers. The molecular weight of the copolymers is nearly independent of the feed ratio in a large range and the polymerization rate dropped with an increase in ATA in feed ratio.     

Determination of the reactivity ratios of methyl acrylate with the vinyl acetate,vinyl 2,2-dimethyl-propanoate,and vinyl 2-ethylhexanoate

The course of composition drift in copolymerization reactions is determined by reactivity ratios of the contributing monomers. Since polymer properties are directly correlated with the resulting chemical composition distribution, reactivity ratios are of paramount importance. Furthermore, obtaining correct reactivity ratios is a prerequisite for good model predictions. For vinyl acetate (VAc), vinyl 2,2-dimethyl-propanoate also known as vinyl pivalate (VPV), and vinyl 2-ethylhexanoate (V2EH), the reactivity ratios with methyl acrylate (MA) have been determined by means of low conversion bulk polymerization. The mol fraction of MA in the resulting copolymer was determined by ¹H-NMR. Nonlinear optimization on the thus-obtained monomer feed–copolymer composition data resulted in the following sets of reactivity ratios: r_MA = 6.9 ± 1.4 and r_VAc = 0.013 ± 0.02; r_MA = 5.5 ± 1.2 and r_VPV = 0.017 ± 0.035; r_MA = 6.9 ± 2.7 and r_V2EH = 0.093 ± 0.23. As a result of the similar and overlapping reactivity data of the three methyl acrylate–vinyl ester monomer systems, for practical puposes these data can be described with one set of reactivity data. Nonlinear optimization of all monomer feed–copolymer composition data together resulted in r_MA = 6.1 ± 0.6 and r_VEst = 0.0087 ± 0.023. © 1994 John Wiley & Sons, Inc.     

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.     

Polymerization of meta-naphthoquinone methide: 3,4-benzo-6-methylenebicyclo [3.1.0] hex-3-ene-2-one

Polymerization behavior of meta-naphthoquinone methide, 3,4-benzo-6-methylenebicyclo[3.1.0]hex-3-ene-2-one ( 1 ), was studied. Radical initiator 2,2′-azobis(isobutyronitrile) (AIBN) induced polymerization of 1 , but ionic initiators potassium tert-butoxide, butyllithium, and boron trifluoride etherate did not. Polymerization of 1 proceeded via ring-opening and aromatization to give a polymer with head-to-tail monomer unit placement. Compound 1 copolymerized with methyl methacrylate (MMA) in the presence of AIBN to obtain the monomer reactivity ratios r₁ ( 1 ) = 0.28 ± 0.07 and r₂(MMA) = 0.39 ± 0.02 at 60°C and Q and e values of Q = 1.04 and e = −1.03, indicating that 1 is a conjugative and electron-donating monomer. Ring-opening and aromatization of 1 also took place in the copolymerization. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 741–746, 1997     

Mechanism of charge-transfer polymerization. XI. Radical copolymerization of N-vinylindole with electron-accepting monomers

N-Vinylindole (NVI) was copolymerized with such electron-accepting monomers as fumaronitrile (FN) or diethyl fumarate (DEF) under initiation with a radical catalyst. The compositions of the copolymers varied from 1:1.1 to 1:1.85 (NVI:FN or DEF). The FN or DEF content in the copolymer increased with increase in the molar fraction of the FN or DEF monomer in the monomer feed. It was suggested that both copolymers have a 1:1 recurring unit of NVI and the electron-accepting monomer, thus being alternating copolymers, and that further addition of the electron-accepting monomer to the indole ring occurred at its electron-rich β-carbon atom.     

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.     

Radical copolymerization of novel trifluorovinyl ethers with ethyl vinyl ether and vinyl acetate: Estimating reactivity ratios and understanding reactivity behavior of the propagating radical

Two novel trifluorovinyl ether (TFVE) monomers were copolymerized with either ethyl vinyl ether (EVE) or vinyl acetate (VAc) in a redox‐initiated aqueous emulsion: 1‐(2‐phenoxyethoxy)‐1,2,2‐trifluoroethene (Ph‐TFVE) and 1‐[2‐(2‐ethoxyethoxy)ethoxy]‐1,2,2‐trifluoroethene (Et‐TFVE). Previous studies demonstrated a propensity for radical hydrogen abstraction from the oligoether pendant group during the homopolymerization of Et‐TFVE with continued propagation of the resulting radical, thereby providing the rationale to investigate the copolymerization of our new TFVEs with EVE or VAc. Reactivity ratios were estimated using the error‐in‐variables model from a series of bulk free radical copolymerizations of Ph‐TFVE with EVE or VAc. The reactivity ratios were r_Ph‐TFVE = 0.25 ± 0.07, r_EVE = 0.016 ± 0.04; r_Ph‐TFVE = 0.034 ± 0.04, r_VAc =0.89 ±0.08. Partial hydrolysis of polymers containing VAc to vinyl alcohol (VA) resulted in two terpolymers: poly(Ph‐TFVE‐co‐VAc‐co‐VA) and poly(Et‐TFVE‐co‐VAc‐co‐VA), respectively. We investigated the possibility of hydrogen abstraction from VAc during polymerization by comparing the molar mass before and after hydrolysis. Abstraction from VAc was not apparent during polymerization; however, abstraction from the oligoether pendant group of Et‐TFVE was again evident and was more significant for those copolymers having a greater fraction of Et‐TFVE in the monomer feed. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 1344–1354, 2000     

Effect of monomer/nanoclay interaction on the kinetics of atom transfer radical homo- and copolymerization of styrene and methyl acrylate

Atom transfer radical homo- and copolymerization of styrene and methyl acrylate initiated with CCl₃-terminated poly(vinyl acetate) macroinitiator were performed at 90°C in the presence of nanoclay (Cloisite 30B). Controlled molecular weight characteristics of the reaction products were confirmed by GPC. It was shown that nanoclay slightly decreased the rate of styrene polymerization, while it significantly enhanced the rate of methyl acrylate polymerization and its copolymerization with styrene. The reactivity ratios of the monomers in the presence and in the absence of nanoclay were calculated (r _St = 1.002 ± 0.044, r _MA = 0.161 ± 0.018 by extended Kelen-Tudos method and r _St = 1.001 ± 0.038, r _MA = 0.163 ± 0.016 by Mao-Huglin method), confirming that the presence of nanoclay has no influence on monomer reactivity. The enhancement in the homopolymerization rate of methyl acrylate as well as its copolymerization rate with styrene was attributed to nanoclay effect on the dynamic equilibrium between active (macro)radicals and dormant species. Dipole moments of the monomers were successfully used to predict structure of the polymer/clay nanocomposites prepared via in situ polymerization.     

Synthesis and radical polymerization of 2-vinyldibenzothiophene

A monomer having dibenzothiophene moiety, 2-vinyldibenzothiophene (1), was prepared by the Ni-catalyzed cross-coupling reaction of vinyl bromide with the Grignard reagent of 2-bromodibenzothiophene. The radical homopolymerization of 1 and the copolymerization with styrene were carried out at 60°C in toluene (1.0M) for 20 h using AIBN (5 mol %) as an initiator to obtain the corresponding polymers in high yields. Thermal analyses of the copolymers showed that both 10% weight loss and glass transition temperatures increase when increasing the content of 1 unit. The monomer reactivity ratio was evaluated as r₁ = 2.55 (1) and r₂ = 0.16 (styrene). © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 2813–2819, 1997     

Alternating Copolymerization of Styrene and N-(4-Bromophenyl)Maleimide

Abstract

Free radical copolymerization of styrene (St) and N(4-bro-mophenyl)maleimide (4BPMI) in dioxane solution gave an alternating copolymer in all proportions of feed comonomer compositions. The monomer reactivity ratios were found to be r ₁, = 0.0218 ± 0.0064 (St) and r ₂, = 0.0232 ± 0.0112 (4BPMI), and the activation energy of the copolymerization reaction for the equimolar ratios of comonomer was E _a, = 51.1 kJ/mol. The molecular weights of the copolymers obtained are relatively high, the T _g's showed similar values (490 K), and the thermal stability is higher than that of polystyrene. The initial rate of copolymerization depends on the total concentration of the comonomers and the maximum occurred at higher 4BPMI mol fractions; however, the overall conversion is highest at equimolar comonomer composition. It has been shown that a charge-transfer complex participates in the process of copolymerization. The initial reaction rate was measured as a function of the monomer molar ratios, and the participation of the charge-transfer complex monomer and the free monomers was quantitatively estimated.     

Cationic copolymerization of β-pinene and epichlorohydrin

β-Pinene and epichlorohydrin (ECH) have been copolymerized cationically using BF₃(C₂H₅)₂O and SnCl₄ as catalysts. Polymerizations were carried out at ?80°C in methylenechloride. Monomer reactivity ratios were determined in both catalysts which were r₁(ECH) = 1.06 ± 0.15 and r₂ (β-pinene) = 0.32 ± 0.08 in BF₃(C₂H₅)₂O and r₁(ECH) = 0.33 ± 0.11 and r₂(β-pinene) = 2.03 ± 0.44 in SnCl₄. Copolymers of different composition were soluble in acetone and insoluble in methanol. This characteristic was taken to indicate that the polymeric products were real copolymers and not a mixture of two homopolymers of epichlorohydrin and β-pinene.     

Homo- and copolymerization of N-(2-thiazolyl)methacrylamide with different vinyl monomers: Synthesis,characterization, determination of monomer reactivity ratios and biological activity

N-(2-thiazolyl)methacrylamide (TMA) monomer was synthesized from 2-aminothiazole by two different methods. The homo- and copolymerization of this monomer with methyl methacrylate (MMA), styrene (St), acrylonitrile (AN), and vinyl acetate (VA) were performed in dimethyl formamide using 1 mol% AIBN at 70°C. The copolymerization behavior was studied in a wide composition interval with the mole fractions of TMA ranging from 0.1 to 0.7 in the feed. Characterization using FTIR and 1HNMR techniques confirmed the structure of the monomer and the prepared homo- and copolymers, but the copolymers compositions were determined from sulphur analysis. The monomer reactivity ratios were computed using Fineman and Ross and Kelen and Tüdös methods for the systems TMA-MMA, TMA-St, TMA-AN and TMA-VA and were found to be r ₁ = 0.59 ± 0.05, r ₂ = 2.72 ± 0.03; r ₁ = 0.39 ± 0.02, r ₂ = 0.90 ± 0.01; r ₁ = 0.77 ± 0.06, r ₂ = 1.99 ± 0.04 and r ₁ = 0.80 ± 0.08, r ₂ = 0.40 ± 0.05 respectively (r ₁ corresponds to monomer reactivity ratio of TMA). The Q and e values for TMA monomer were found to be 1.079 and ?0.054. The synthesized monomer and polymers were tested in vitro for biological activity against some microorganisms, using the disk diffusion technique. Generally, all the polymers were effective against the tested microorganisms, but their growth-inhibition effects varied.     

Reactivity ratios and sequence structures of the copolymers prepared using photo‐induced copolymerization of MMA with MTMP

4‐Methacryloyl‐2,2,6,6‐tetramethyl‐piperidine (MTMP) was applied as reactive hindered amine piperidine. Photo‐induced copolymerization of methyl methacrylate (MMA, M₁) with MTMP (M₂) was carried out in benzene solution at ambient temperature. The reactivity ratios for these monomers were measured by running a series of reactions at various feed ratios of initial monomers, and the monomer incorporation into copolymer was determined using ¹H NMR. Reactivity ratios of the MMA/MTMP system were measured to be r₁ = 0.37 and r₂ = 1.14 from extended Kelen‐Tüdos method. The results show that monomer MTMP prefers homopolymerization to copolymerization in the system, whereas monomer MMA prefers copolymerization to homopolymerization. Sequence structures of the MMA/MTMP copolymers were characterized using ¹H NMR. The results show that the sequence structure for the main chain of the MMA/MTMP copolymers is mainly composed of a syndiotactic configuration, only with a little heterotactic configuration. Three kinds of the sequences of rr, rr′, and lr′ in the syndiotactic configuration are found. The sequence‐length distribution in the MMA/MTMP copolymers is also obtained. For f₁ = 0.2, the monomer unit of MMA is mostly separated by MTMP units, and for f₁ = 0.6, the alternating tendency prevails and a large number of mono‐sequences are formed; further up to f₁ = 0.8, the monomer unit of MTMP with the sequence of one unit is interspersed among the chain of MMA. Copyright © 2012 John Wiley & Sons, Ltd.     

Copolymerization of glycidyl methacrylate with alkyl acrylate monomers

A newer approach to obtaining acrylic thermoset polymers with adequate hydrophilicity required for various specific end uses is reported. Glycidyl methacrylate (GMA) was copolymerized with n-butyl acrylate (n-BA), isobutyl acrylate (i-BA), and 2-ethylhexyl acrylate (2-EHA) in bulk at 60°C. with benzoyl peroxide as free radical initiator. The copolymer composition was determined from the estimation of epoxy group. Reactivity ratios were calculated by the Yezrielev, Brokhina, and Roskin method. For copolymerization of GMA (M₁) with n-BA (M₂) the reactivity ratios were r₁ = 2.15 ± 0.14, r₂ = 0.12 ± 0.03; with i-BA (M₂) they were r₁ = 1.27 ± 0.06, r₂ = 0.33 ± 0.031; and with 2-EHA (M₂) they were r₁ = 2.32 ± 0.14, r₂ = 0.13 ± 0.009. The reactivity ratios were the measure of distribution of monomer units in a copolymer chain; the values obtained are compared and discussed.     

Synthesis and Polymerization of N-(L-Menthylcarboxylatomethyl)maleimide

A new type of optically active N-(L-menthylcarboxylatomethyl)maleimide (MGMI) was synthesized from maleic anhydride, glycine, and L-menthol. Radical homopolymerization of MGMI was performed at 50°C for 24 h to give optically active polymer having [α]_D = -57°. Radical copolymerizations of MGMI (M ₁) were performed with styrene (ST, M ₂), methyl methacrylate (MMA, M ₂) in benzene at 50°C. From the results, the monomer reactivity ratios (r ₁, r ₂) and the Alfrey-Price Q, e values were determined as follows: r ₁ = 0.16, r ₂ = 0.006 for the MGMI-ST system; r ₁ = 0.15, r ₂ = 1.65 for the MGMI-MMA system, and Q ₁ = 0.72, e ₁ = 1.59 calculated from the MGMI-MMA system. Anionic homopolymerizations of MGMI were also carried out. Chiroptical properties of the polymers were investigated.