Copolymerization of vinyl acetate with benzylidenemalononitrile

Vinyl acetate was copolymerized with benzylidenemalononitrile in bulk by radical initiation at 80°C up to low conversions. Alternating copolymers were formed over a wide range of monomer feed ratios. The copolymerization parameters were determined by the conventional scheme. The copolymers were characterized by IR, proton, and ¹³C spectroscopy and their basic properties, solubility, viscosity, and thermal behavior were determined.     

Copolymerization of studies. Copolymerization of methyl α-cyanocrotonate with styrene,acrylonitrile, and vinyl acetate

Copolymers of methyl α-cyanocrotonate with styrene, acrylonitrile, and vinyl acetate were prepared in bulk by free radical initiation. The copolymerization parameters were determined for each pair by several methods. The basic properties, that is, intrinsic viscosity, solubility, melting range, and glass transition temperature of the obtained copolymers, were determined.     

Copolymerization of acrylonitrile. I. Copolymerization with styrene derivatives containing nitrile groups in the side chain

Acrylonitrile was copolymerized in bulk with cinnamonitrile (I), ethyl benzylidenecyanoacetate (II), and benzylidenemalononitrile (III) by radical initiation up to low conversions. The conventional scheme of copolymerization fitted all the three copolymer pairs.     

Copolymerization of acrylonitrile. III. Copolymerization with α-cyanocinnamamide

Acrylonitrile was copolymerized in solution with α-cyanocinnamamide up to low conversions. The conventional scheme of copolymerization fitted this copolymer. The basic properties, such as solubility, viscosity, and thermal behavior, of the copolymer prepared in bulk and in solution were determined.     

Kinetics of Free Radical Copolymerization. IV. Rate of Initiation in the Copolymerization System Ethyl Acrylate-Styrene-Benzene

Dependence of the rate constant of initiation on the overall concentration and composition of monomer has been investigated in the free radical copolymerization of ethyl acrylate and styrene in bulk and in benzene solution at 50° C. The rate constant of initiation has been determined by the inhibition method using triphenyl-verdazil as the stable free-radical inhibitor. An equation has been derived to calculate the rate constant of initiation in a copolymerization system, where both monomers undergo a pseudounimolecular side reaction with the inhibitor. The rate constant of initiation in the copolymerization mixture is a linear composition of rate constants determined separately in the pure constituents of the system.     

Copolymerization of 2-hydroxypropyl methacrylate with alkyl acrylate monomers

2-Hydroxypropyl methacrylate has been copolymerized with methyl acrylate, ethyl acrylate, n-butyl acrylate, and methyl methacrylate in bulk at 60°C using benzoyl peroxide as initiator. The compositions of copolymers have been determined by the estimation of the hydroxyl group by acetylation process. The copolymerization parameters have been determined by conventional scheme of copolymerization.     

Copolymerization of styrene with vinyltriethoxysilane and vinyltriacetoxysilane

Styrene was copolymerized in bulk with vinyltriethoxysilane at 80°C and vinyltriacetoxysilane at 60, 80, and 100°C with the use of benzoyl peroxide as an initiator at low conversions. Copolymer composition was determined from the silicon content and reactivity ratios were calculated by the conventional scheme of copolymerization. The low r₁ value (styrene) in the styrene-vinyltriacetoxysilane system (St–VTAS) as compared to styrene-vinyltriethoxysilane (St–VTES) copolymerization may be attributed to higher reactivity of VTAS towards the polystyryl radical. Further, in the St–VTAS system, r₁ tends to decrease with increasing polymerization temperature. The influence of silicon comonomer on properties of the copolymers (intrinsic viscosity, solubility, dielectric and thermal behavior) was studied.     

Temperature and pH Dependency of Copolymerization Parameters of Acrylic Acid and 2-Hydroxypropyl Acrylate

Summary: Since copolymerization parameters of acrylic acid (AA) and 2-hydroxypropyl acrylate (HPA) in aqueous solutions are scarcely investigated a new method and different experimental setups were developed to run copolymerization experiments at different temperatures and pH values. The experiments were done with UV- or azo- initiation and analyzed by residual monomer analytics with HPLC and GPC methods. Based on the data obtained the conversion and copolymerization parameters were calculated with different mathematical models.     

Donor-Acceptor Complexes in Copolymerization. LIX. Alternating Diene-Dienophile Copolymers. 13. Copolymerization of Dicyclopentadiene and Maleic Anhydride

The solution and bulk copolymerization of dicyclopentadiene (DCP) and maleic anhydride (MAH) occurs over the temperature range 80–240°C, upon the addition of a free-radical catalyst which has a short half-life at the reaction temperature. An unsaturated 1/1 MAH/DCP copolymer, derived from the copolymerization of MAH with the norbornene double bond, followed by a Wagner-Meerwein rearrangement, is obtained in the presence of a large excess of DCP at 80° C, while a saturated 2/1 MAH/ DCP copolymer, derived from the cyclocopolymerization of the residual cyclopentene unsaturation, is obtained at higher temperatures or in the presence of excess MAH. The copolymers prepared under other conditions with intermediate MAH/DCP mole ratios contain both 1/1 and 2/1 repeating units. The copolymer obtained from bulk copolymerization above 170° C contains units derived from cyclopentadiene-MAH cyclocopolymerization as well as DCP-MAH copolymerization.     

Study of the Isothermal Bulk Copolymerization of Acrylic and Methacrylic Acid Esters

The course and kinetics of the isothermal bulk polymerization of ethyl acrylate, 2-ethylhexyl acrylate, and methyl methacrylate and their copolymerization in different mol ratios were studied by differential scanning calorimetry at 363 K. The initiator used was 2,2′-azoisobutyronitrile. The courses of reaction, the copolymerization enthalpies, the copolymerization parameters, and the specific constants of the rate of polymerization were determined.     

Copolymerization of N-vinylpyrrolidone with 3-methacryloyloxytetrahydrothiophene 1,1′-dioxide

Radical copolymerization of N-vinylpyrrolidone with 3-methacryloyloxytetrahydrothiophene 1,1′-dioxide in the bulk and in dimethyl sulfoxide in the range of low conversions was studied. The kinetic features of copolymerization were examined. The relative activities of monomers and the structure and some characteristics of the copolymers were determined.     

Copolymerization of styrene and diethyl fumarate with ZnBr2. IV. Comparison between photoinitiation and electroinitiation

A comparative analysis of photoinitiation and electroinitiation can help elucidate initiation processes in donor-acceptor charge-transfer copolymerization. The technique has been applied to the zinc bromide-catalyzed copolymerization of styrene and diethyl fumarate in methanol. The photocopolymer product was analyzed by GPC, NMR, and elemental analysis. The results showed that 1:1 copolymers were formed initially, but changes occurred in both the kinetics and products after the early stages of the reaction. Significant correlations found between the two initiation methods included the initial kinetic order with respect to the initiating process and the effect on product yield of equivalent increases in total initiation energy. The limiting value of zinc bromide for both initiation methods was found to be the same. The data obtained support the contention that the copolymerization proceeds through a donor–acceptor process and that photoactivation of the preformed complex, inducing electron transfer, is a likely initiation process.     

Equilibrium Copolymerization. III. Sequence Distribution in Equilibrium Copolymer

The sequence distributions for the copolymers generated in three cases of binary equilibrium copolymerization, including the effect of the ultimate unit, are studied theoretically. From the equilibrium sequence distribution functions, the copolymer sequence structure, the number- and weight-average sequence lengths of monomer units, the run number, the randomness parameter, and the fractions of different diads in the copolymer are derived. According to the relation between the parametric variables introduced in the formulas and the equilibrium copolymerization conditions, all of the structural sequence parameters of the resulting copolymers can be predicted from the comonomer feed composition and the equilibrium constants for initiation and propagation. Finally, the relation between the reaction temperature and the structural sequence parameters is given.     

Copolymerization of 2,2-diallyl-1,1,3,3-tetraethylguanidinium chloride and alkyl methacrylates

Radical copolymerization of 2,2-diallyl-1,1,3,3-tetraethylguanidinium chloride with methyl methacrylate and allyl methacrylate in the bulk and methanol solution in the presence of azobis-isobutyric acid dinitryle at 70–90°C has been studied. Copolymerization of 2,2-diallyl-1,1,3,3-tetraethylguanidinium chloride with methyl methacrylate or allyl methacrylate in the bulk proceeds with formation of random copolymers enriched in methacrylate units; in the copolymerization of 2,2-diallyl-1,1,3,3-tetraethylguanidiny chloride with methyl methacrylate in methanol, the copolymerization constants of the monomers become close. The kinetic parameters of the reaction have been studied, the relative activities of the monomers have been determined. It has been found that 2,2-diallyl-1,1,3,3-tetraethylguanidinium chloride is copolymerized with allyl methacrylate or methylmethacrylate to form pyrrolidinium structures in the cyclolinear polymer chain. At high degrees of conversion of the copolymerization of 2,2-diallyl-1,1,3,3-tetraethylguanidinium chloride with allyl methacrylate, the viscosity increases and the side polymer chains are crosslinked by “allyl bonds” to form insoluble copolymers, swelling in benzene and DMSO.     

Kinetics of Free Radical Copolymerization. VII. Kinetic Analysis of Ethyl Acrylate-Styrene Copolymerization in Inert Solvent

The copolymerization kinetics of the ethyl acrylate/styrene/azo-bis-isobutyronitrile/benzene/50°C system was found to deviate from the classical rate equation of copolymerization. The experimental results could not be interpreted by the diffusion theory, the penultimate effect, or the theory of electron donor-acceptor complexes. Our kinetic data were consistently described by the theory of hot radicals, and the 13 parameters characteristic for the copolymerization system were determined from an adequate number of data at different compositions by a nonlinear least-squares method.     

Radiation-Induced Copolymerization of Tetrafluoroethylene and Propylene. 2. Copolymerization in Solution

Copolymerization of tetrafluoroethylene and propylene in chlorofluorohydrocarbon solvents was carried out below room temperature with γ-rays from a ⁶⁰Co source. A remarkable rate-accerelating effect was observed in these solution systems, although the activation energies and the compositions of copolymers were almost the same as those in bulk system. The most effective solvent was found to be trichlorotrifluoroethane. Kinetic results of the copolymerization in trichlorotrifluoroethane solution system revealed the role of solvent to be complicated, with the possibility of affecting almost all reaction steps of the polymerization.     

Plasma Copolymerization of Pyrrole with Si-Compounds

The plasma copolymerization of pyrrole with hexamethyldisiloxane, hexamethyldisilane and hexamethyldisilazane was investigated with regard to the polymer deposition characteristics and the properties of the product films. Deposition rates were evaluated by monitoring the weight increase of the deposits over time, and the effect of varying the experimental set up parameters was determined. The results of deposition rates and quantitative IR analysis suggested that the increasing amounts of Si-components were incorporated into the polymer matrix as the supply ratio of the Si-monomer was increased. The Si-component in the copolymer brought some dramatic effects on the physical properties of the films and changed the hydrophobicity of the surfaces, as reflected in the advancing and receding contact angle measurements. The experimental results obtained are discussed in terms of the contribution of the polar and dispersion components of surface energy.     

Copolymerization kinetics of methyl methacrylate-styrene obtained by PLP-MALDI-ToF-MS

The combination of MALDI-ToF-MS and pulsed laser polymerization has been used to study the propagation rate coefficients for the copolymer system styrene-methyl methacrylate. For the first time, complete information regarding mode of termination, reactivity of photoinitiator-derived radicals, copolymer molecular mass, chemical composition, and copolymerization rates is obtained interrelated. The polymerizations were carried out in bulk with varying styrene concentrations at a temperature of 15.2 degrees C by an excimer pulsed laser with varying frequencies. Both chemical composition distributions and molecular weight distributions were determined by MALDI-ToF-MS. The data were fitted to the implicit penultimate unit model and have resulted in new point estimates of the monomer and radical reactivity ratios for the copolymer system styrene-methyl methacrylate: r(St) = 0.517, r(MMA) = 0.420, s(St) = 0.296, s(MMA) = 0.262. Comparison between Monte Carlo simulations and the obtained results further confirmed the very successful combination of pulsed laser copolymerization experiments with MALDI-ToF-MS. The obtained results are believed to be the most accurate and complete set of copolymerization parameters to date.     

Kinetics of Copolymerization. III. Determination of the Rate of Initiation in the Copolymerization System Acrylonitrile/Methyl Acrylate/Dimethylformamide

For the AIBN-initia ted copolymerization System acryionitriie/methyl methacrylate/dimethylformamide, the dependence of the composition of the monomer mixture on the rate constant of initiation and that of the initiator decomposition has been inves-tigated at 313, 323, and 333° K. It was established that the rate constant of initiator decomposition is independent of, while that of the initiation is dependent on, the composition of the monomer mixture. The efficiency of initiation has been calculated and its value was found to be somewhat altered not only by the composition of the monomer mixture but also decreased siightiy with an increase of temperature.