Effect of solvent nature on free-radical copolymerization of N,N-diallyl-N,N-dimethylammonium chloride and maleic acid

The free-radical copolymerization of N,N-diallyl-N,N-dimethylammonium chloride with maleic acid in DMSO proceeds to yield statistical copolymers. When the reaction is carried out in methanol, the copolymers of constant compositions (N,N-diallyl-N,N-dimethylammonium chloride: maleic acid = 2: 1) are formed over a wide range of comonomer ratios in the starting mixture. The formation of alternating copolymers in this case may be attributed to formation of donor-acceptor complexes between the comonomers in the methanol solution, as evidenced by UV spectrophotometry. The kinetic features of the process have been investigated, and the relative activities of the monomers have been assessed. ¹³C NMR studies have demonstrated that, regardless of the solvent nature, both double bonds of N,N-diallyl-N,N-dimethylammonium chloride are involved in copolymerization via intermolecular cyclization accompanied by formation of pyrrolidinium structures.     

Copolymerization of N,N-diallyl-N,N-dimethylammonium chloride with ethylene glycol vinyl ether in aqueous medium

The radical copolymerization of N,N-diallyl-N,N-dimethylammonium chloride (AMAC) (M₁) with ethylene glycol vinyl ether (M₂) in an aqueous medium proceeds at a high rate to afford random copolymers. The reactivity ratios equal to r ₁ = 2.18 and r ₂ = 0.01 indicate that AMAC is a more active comonomer. The overall reaction order in comonomers is 2.4, and the effective activation energy is 97.4 ± 2 kJ/mol. The monomer M₁ enters into copolymerization by both of the double bonds with the formation of pyrrolidinium structures in the chain through the cyclization stage.     

Radical copolymerization of N,N-Diallyl-N,N-dimethylammonium chloride and fumaric acid

The copolymerization of N,N-diallyl-N,N-dimethylammonium chloride and fumaric acid under conditions of radical initiation is studied. The reaction yields copolymers that exhibit a random distribution of comonomer units in the macrochain. Fumaric acid is highly active in the copolymerization of the above system. A significant effect on the relative activity of the comonomers is exerted by the type of solvent. The kinetics of the copolymerization is studied; the structuring of the copolymers is determined.     

Radical copolymerization of <Emphasis Type="Italic">N,N</Emphasis>-diallyl-<Emphasis Type="Italic">N,N</Emphasis>-dimethylammonium chloride and maleic acid in various solvents

Radical copolymerization of N,N-diallyl-N,N-dimethylammonium chloride with maleic acid in various solvents was studied. The solvent effect on the relative activity of the monomers and the possibility of preparing copolymers of preset composition were examined.     

Effect of Chemical Structure and Charge Distribution on Behavior of Polyzwitterions in Solution

Summary: The hydrodynamic and conformational properties of polyelectrolyte poly(N,N-diallyl-N,N-dimethylammonium chloride) and its corresponding polybetaine poly(2-diallyl(methyl)ammonio)acetate) molecules in aqueous solutions with various ionic strength and pH, were studied by viscometry, static and dynamic light scattering methods. It was established that a 1 M NaCl solution is a thermodynamically good solvent for poly(N,N-diallyl-N,N-dimethylammonium chloride). In water solutions conformation of poly(2-diallyl(methyl)ammonio)acetate) molecules corresponds to polymer coil under θ–conditions. An increase in the concentration of NaCl in water and 0.1M NaOH solutions from 0 to 1 mol/l brings about a sharp gain in the intrinsic viscosity of the polymer and in the hydrodynamic radius of molecules. This effect results from the decomposition of zwitterion pairs responsible for the compact conformation of polymer molecules in water and 0.1 M NaOH. The Kuhn segment length for poly(2-diallyl(methyl)ammonio)acetate) molecules A = 6.3 nm determined in water and in 0.1 M NaOH solutions practically coincided with A value 6.6 nm, received in 1 M NaCl and in 0.1 M NaOH/1M NaCl. For poly(N,N-diallyl-N,N-dimethylammonium chloride) molecules in 1 M NaCl solutions A = 3.9 nm.     

Molecular properties of the copolymers of <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-diallyl-<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-dimethylammonium chloride and maleic acid

The hydrodynamic and conformational properties of molecules of poly(N,N-diallyl-N,N-dimethylammonium chloride) and N,N-diallyl-N,N-dimethylammonium chloride-maleic acid copolymers of different compositions in solutions with various ionic-strength and pH values, as well as of the polyelectrolyte complex based on the copolymer with dodecyl sulfate anions in chloroform, are studied. For poly(N,N-diallyl-N,N-dimethylammonium chloride) molecules in a 1 M NaCl solution, the Kuhn segment length and the hydrodynamic diameter of the chain are estimated as A = 3.9 nm and d = 0.48 nm, respectively. In acidic solutions with pH 3.5, the copolymers demonstrate behavior typical for polyelectrolytes. In an alkaline solution with pH 13, when 1 M NaCl is added to the solution of the copolymer containing 29 mol % maleic acid units, there is an antipolyelectrolyte effect that manifests itself as an increase in the intrinsic viscosity of the copolymer and in the hydrodynamic radius of its molecules. It is found that an increase in the fraction of maleic acid units in the copolymer from 12 to 42 mol % brings about a reduction in the equilibrium rigidity of its macromolecules from 4.1 to 2.2 nm. The equilibrium rigidity of polyelectrolyte-complex molecules is higher than that of initial copolymer molecules owing to steric interactions arising between the aliphatic chains of dodecyl sulfate anions. In an electric field, the molecules of the complex are oriented owing to the induced dipole moment resulting from the displacement of dodecyl sulfate anions along the chain contour.     

N-vinylpyrazole copolymers

Copolymers of N-vinylpyrazole with N-vinyl-4,5,6,7-tetrahydroindole and vinyl acetate were prepared by radical copolymerization. The composition, structure, and properties of the copolymers were studied. The reactivity constants of the monomers were calculated. Copolymer films were prepared from solutions by casting, and the proton conductivity of the films was determined.     

Complexation of sodium 2-acrylamido-2-methylpropanesulfonate-monoethanolamine vinyl ether copolymer with polyelectrolytes in aqueous medium

A new water-soluble polyelectrolyte—the copolymer of sodium 2-acrylamido-2-methylpropanesulfonate and monoethanolamine vinyl ether—has been synthesized by free-radical copolymerization. The concentration behavior of the reduced viscosity of copolymer solutions that is typical for polyelectrolytes has been revealed. The reactivity ratios of the monomers have been measured. These values indicate a lower reactivity of monoethanolamine vinyl ether than that of sodium 2-acrylamido-2-methylpropanesulfonate. The complexation of this copolymer with poly(acrylic acid) and poly(N,N-dimethyl-N,N-diallylammonium chloride) has been studied. It has been found that the copolymer demonstrates the polyampholytic behavior and is able to form interpolymer complexes both with polycations and polyanions. It has been established that the polycomplex of the copolymer with polyacrylic acid has the unfolded structure due to the presence of sulfonate groups uninvolved in complexation, while the complex of the copolymer with poly(N,N-dimethyl-N,N-diallylammonium chloride) is compact owing to enhancement of hydrophobic interactions, and the sizes of its species are of the order of 80 nm.     

Determination of the reactivity parameters for the copolymerization of butyl acrylate with vinyl acetate

The composition of vinyl acetate–butyl acrylate copolymers obtained with batch emulsion polymerization have been studied by ¹H-NMR. Using the integrated copolymerization Meyer–Lowry equation, the apparent reactivity ratios of the two monomers were calculated as 10.67 for r₁, the reactivity ratio of butyl acrylate (BA), and 0.024 for r₂, the reactivity ratio of vinyl acetate (VAC). These results were compared with those obtained by other methods.     

Remote Unit Effects in the Copolymerization of Unconjugated Monomers

The kinetics of the radical copolymerization of the three binary systems vinyl chloride (C)-vinyl acetate (Ac), vinylidene chloride (V)-vinyl acetate, and vinyl chloride-vinylidene chloride have been investigated in the whole range of monomer feed composition using the chromatographic method. Penultimate or antepenultimate effects have been observed in all cases. The better values of the corresponding reactivity ratios are: For C-Ac copolymers, r_Ac = 0.29, r_CCC = 1.67, r_AcCC. = 4.60, and r_AcC = 2.05. For V-Ac copolymers, r_Ac = 0.07, r_VVV = 5.30, r_AcVV = 11.5, r_AcAcV = 8.0, and r_VAcV = 6.0. For C-V copolymers, r_VAcV = 0.22, r_VV = 2.94, and r_CV = 4.31. An internal transfer mechanism is suggested for the antepenultimate effect in the vinyl acetate copolymers.     

13C-NMR study of chlorinated ethylene–vinyl acetate copolymers

¹³C-NMR has been used to analyze the microstructures of a series of experimental chlorinated ethylene–vinyl acetate copolymers (15–56% CI). Previously established line assignments for EVA copolymers and substituent effect parameters for chlorine have enabled us to tentatively assign partial structures up to five carbon atoms in length. The ¹³C-NMR analyses of a commercial vinyl chloride–vinyl acetate copolymer, a commercial vinyl chloride–vinyl acetate–ethylene terpolymer, and a commercial chlorinated polyethylene support the structural assignments. Data obtained for the experimental resins indicate that the acetate groups influence the way in which chlorine is added to the polymer chain. furthermore, the data indicate the acetate groups undergo little, if any, chlorination.     

Dilute solutions of polyelectrolytes—IV. Unperturbed dimensions of N,N-diethylacrylamide-N,N-dimethyldiallylammonium chloride copolymers

The behaviour of copolymers of N,N-diethylacrylamide with N,N-dimethyldiallylammonium chloride in aqueous NaCl solution has been studied by light-scattering. The parameters characterizing the short- and long-range interactions have been calculated. The influence of copolymer composition on the gyration radius and unperturbed dimensions shows that the macromolecules have maximum flexibility for a composition near equimolar. This behaviour was attributed to decrease of both the electrostatic repulsions and the steric hindrance of the structural units, as a result of pronounced alternation.     

Radical reactions involving esters of fumaric acid—I. Copolymerizations

¹⁴C-labelled samples of diethyl-, ethyl n-hexyl- and di-n-hexyl fumarates have been used in studies at 60° of their radical copolymerizations with styrene and with vinyl acetate. Changing the diluent from benzene to dimethylformamide in some of the copolymerizations had no effect on the compositions of the copolymers. Monomer reactivity ratios have been calculated for most of the systems; comparisons have been made of the reactivities of the fumarate esters towards the polyvinyl acetate radical.     

Homopolymers and vinyl chloride copolymers of vinyl esters of chlorinated fatty acids from umbelliferae and limnanthes douglasii

Homopolymers and copolymers of vinyl esters of chlorinated C₁₈, C₂₀, and C₂₂ fatty acids with vinyl chloride have been prepared and evaluated. The incorporation of the vinyl ester of chlorinated C₁₈, C₂₀, and C₂₂ acids as comonomers with vinyl chloride produced more flexible copolymers than have other comonomers, yet none have imparted the plasticization that can be obtained by an equal amount of external plasticizer.     

Copolymer of N,N-diallyl-N,N-dimethylammonium chloride with sulfur dioxide as carrier of drugs

Immobilization of drugs on macromolecules of copolymer N,N-diallyl-N,N-dimethylammonium chloride with sulfur dioxide using ion exchange technique was investigated. Ways of producing polymer-drug conjugates of preset compositions were developed. Their structure was found by NMR and IR spectroscopy.     

Copolymers of 1-methylcyclopropene

1-Methylcyclopropene (MCP) copolymerizes rapidly with acrylic and vinyl monomers to form soluble, high molecular weight products containing enchained cyclopropane rings. The high electron availability in the cyclopropene double bond promotes one-to-one alternating copolymerization with sulfur dioxide, maleic anhydride, acrylic acid, acrylonitrile, dialkyl fumarates and acrylic esters. Nonalternating copolymers are obtained with vinyl chloride and vinyl acetate, and attempted copolymerization fails entirely with styrene, α-methylstyrene and isoprene. This pattern of copolymerization reactivity resembles that of highly compressed ethylene. Methylcyclopropene copolymers have high glass temperatures in spite of the small size of the MCP unit. The combination of high T_g and small size allows preparation of copolymers with high T_g having a wide range of ductilities and cohesive energy densities.     

Novel supramolecular block copolymer containing organic–inorganic pentablock copolymer by ATRP of styrene and vinyl acetate using polydimethylsiloxane/cyclodextrin inclusion complexes as macroinitiator

Organic–inorganic pentablock copolymers have been synthesized via atom transfer radical polymerization (ATRP) of styrene (St) and vinyl acetate (VAc) monomers at 60 °C using CuCl/N,N,N′,N″,N″-pentamethyldiethylenetriamine as a catalyst system initiated from boromoalkyl-terminated poly(dimethylsiloxane) (PDMS)/cyclodextrins macroinitiator (Br-PDMS/γ-CD). Br-PDMS-Br was reacted with γ-CD in different conditions with inclusion complexes being characterized through hydrogen nuclear magnetic resonance (¹H NMR) and differential scanning calorimetry (DSC). Resulting Br-PDMS-Br/γ-CD inclusion complexes were taken as macroinitiators for ATRP of St and VAc. Well-defined poly(styrene)-b-poly(vinyl acetate)-b-poly(dimethylsiloxane/γ-cyclodextrin)-b-poly(vinyl acetate)-b-poly(styrene) (PSt-b-PVAc-b-PDMS/γ-CD-b-PVAc-b-PSt) pentablock copolymer was characterized by ¹H NMR, gel permeation chromatograph (GPC) and DSC. There was a good agreement between the number-average molecular weight calculated from ¹H NMR spectra and that of theoretically calculated. Pentablock copolymers consisting of Br-PDMS-Br/γ-CD inclusion complex as central blocks (inorganic block) and PVAc and PSt as terminal blocks were synthesized by this technique. PSt-b-PVAc-b-PDMS/γ-CD-b-PVAc-b-PSt pentablock copolymer can undergo a temperature-induced reversible transition upon heating of the copolymer complex from white complex at 22 °C to green complex in 55 °C which characterized with XRD and ¹H NMR. XRD showed a change in crystallinity percent of St peak with changing the temperature which calculated by Origin75 software.     

Thermal stability of copolymers of vinyl acetate and methyl acrylate

The thermal degradation of a series of copolymers of vinyl acetate and methyl acrylate and the two homopolymers poly(vinyl acetate) and poly(methyl acrylate) obtained using Ce(IV) as initiator has been investigated using differential thermal analysis (DTA) and thermogravimetry (TGA) in dynamic nitrogen. The kinetic parameters E, n, and A have been obtained following several methods of thermogravimetric analyses. The stability increases as the methyl acrylate content in the copolymer composition increases. The incorporation of 5 mol % of vinyl acetate in the copolymer produces a marked decrease in stability compared to the homopolymer poly(methyl acrylate). There is evidence for an intramolecular lactonization process in vinyl acetate—methyl acrylate copolymers.     

Copolymerization of Allilidene Diacetate with Vinyl Acetate

Abstract

The monomer reactivity ratios for vinyl acetate (VAc)-allilidene diacetate (ADA) copolymerization have never been obtained. The composition of VAc-ADA copolymers was determined by NMR spectroscopy, measuring CH protons corresponding to ADA at 3.1τ and VAc at 5.1τ. The monomer reactivity ratios were evaluated; r₁ = 1.34 ± 0.05 and r₂ = 0.48 ± 0.03, where M₁ = ADA and M₂ = VAc. From these values the Q and e values for ADA were calculated: Q = 0.047 and e = 0.44 by taking Q = 0.026 and e = ?0.22 for VAc. The H value [1] for copolymerization of ADA, VAc, and vinyl chloride (VC) is 0.87.     

Miniemulsion polymerization of styrene using well-defined cationic amphiphilic comblike copolymers as the sole stabilizer

Well-defined, positively charged, amphiphilic copolymers containing long alkyl side chains were used as stabilizers in the miniemulsion polymerization of styrene. The copolymers were prepared by controlled free-radical copolymerization of styrene and vinyl benzyl chloride using either the reversible addition-fragmentation chain transfer method or TEMPO-mediated polymerization. The benzyl chloride moities were modified by two different long alkyl chain tertiary amines (N,N-dimethyldodecyl amine and N,N-dimethylhexadecyl amine) to yield the amphiphilic copolymers with vinylbenzyl dimethyl alkyl ammonium chloride units. Owing to their high structural quality, only a small amount of these copolymers was required to stabilize the latex particles (0.5–2 wt% vs styrene). Moreover, in the absence of any hydrophobic agent, the amphiphilic comblike copolymer preserved the colloidal stability of both the initial liquid miniemulsion and the final latex. Ill-defined, analogous copolymers were synthesized by conventional free-radical polymerization and in comparison, exhibited poor stabilization properties.