Influence of hydrophobe content on the solution rheology of hydrophobically modified terpolymer of SO2, N,N-diallyl-N-carboethoxymethylammonium chloride

Rheological properties of hydrophobically modified copolymer of SO₂, N,N-diallyl-N-carboethoxymethylammonium chloride and the hydrophobic monomer N,N-diallyl-N-octadecylammonium chloride were studied. The influence of hydrophobe content (HP) and polymer concentration was investigated. Polymers with HP content in the range 1.5-5% were examined and the concentration was varied in the range 2-5 wt%. Both dynamic and steady-shear experiments were performed in ARES rheometer. Copolymers were observed to exhibit typical viscoelastic behavior even with low HP content. Both the dynamic viscosity, η′ and storage modulus, G′, increase with the increase of both the polymer concentration and the HP content of the system. The viscosity of the high HP content polymer showed a strong shear dependency, while G′ was a weak function of frequency and gel-like behavior was observed. The zero-shear viscosity, η₀, showed a strong concentration dependency (η₀ ∼ ?^α; 1.1 < α < 5.9). The concentration dependency of η₀ suggests that intermolecular association is dominant in the high HP content polymer. Control of the HP content and polymer concentration of this class of polymers can lead to a wide range of interesting rheological properties.     

Rheological behavior of associating ionic polymers based on diallylammonium salts containing single-, twin-, and triple-tailed hydrophobes

The cycloterpolymerizations of N,N-diallyl-(4-octyloxy)benzyl-, N,N-diallyl-(3,5-dioctyloxy)benzyl-, and N,N-diallyl-(3,4,5-trioctyloxy)benzyl-ammonium chloride (0-8 mol%) with hydrophilic monomer N,N-diallyl-N-carboethoxymethylammonium chloride and sulfur dioxide afforded a series of cationic polyelectrolytes (CPE). The CPEs were treated with HCl and NaOH to produce the corresponding pH-responsive cationic acid salts (CAS) and polybetaines (PB), anionic polyelectrolytes (APE) as well as polymers PB/APE containing various proportions of zwitterionic (PB) and anionic fractions (APE) in the polymer chain. Likewise, the cycloterpolymerizations of these single-, twin-, and triple-tailed hydrophobes (0-12 mol%) with hydrophilic monomer diallyldimethylammonium chloride and sulfur dioxide afforded a series of CPE in excellent yields. The polymers were characterized by different techniques including NMR and IR. The solution properties of the series of CPE were investigated by rheological techniques. The studied water soluble polymers showed different rheological behavior depending on their structure (hydrophobe type and content) as well as salinity and pH. The high shear thinning and the formation of networks at low shear would likely promote the use of such polymers in enhanced oil recovery applications.     

Aggregation behaviour of hydrophobically modified poly(allylammonium) chloride

 The behaviour of hydrophobically modified poly(allylammonium) chloride having octyl, decyl, dodecyl and hexadecyl side chains has been studied in aqueous solution using fluorescence emission techniques. Micropolarity studies using the I ₁/I ₃ ratio of the vibronic bands of pyrene show that the formation of hydrophobic microdomains depends on both the length of the side chain and the polymer concentration. The I ₁/I ₃ ratio of the polymers with low hydrophobe content (less than 5% mol) changes substantially when reaching a certain concentration. These changes are assigned to aggregation originating from interchain interactions. This behaviour is also confirmed by the behaviour of the monomer/excimer emission intensities of pyrenedodecanoic acid used as a probe. For polymers having dodecyl side chains and hydrophobe contents higher than 10%, aggregates are formed independently of the polymer concentration. Anisotropy measurements show that microdomains resulting from the inter- and/or intramolecular interactions are similar to those observed for cationic surfactants. Viscosity measurements show that the coil dimensions are substantially decreased for the polymers having high hydrophobe contents, indicating intramolecular associations. Received: 10 November 1999/Accepted: 7 April 2000     

SYNTHESIS CHARACTERIZATION AND REMEDIATION POTENTIAL OF POLYMERIZABLE SURFACTANT MONOMERS OF N,N-DIALLYL-N,N-DIALKYL AMMONIUM CHLORIDE

The amphiphilic polymerizable surfactants N,N-diallyl-N,N-dioctylammonium chloride, N,N-diallyl-N,N-didecylammonium chloride and N,N-diallyl-N,N-didodecylammonium chloride have been synthesized. Experimental techniques including dynamic light scattering, fluorescence spectroscopy, nuclear magnetic resonance, and atomic force microscopy indicate the monomers form large, well-organized structures similar to vesicles of naturally occurring lipids. Studies of the sequestration of a model foulant by the didodecyl monomer revealed a strong interaction with a high degree of binding. The loading of higher amounts of cresol causes a change in the properties of the monomer assemblies indicating the formation of mixed micellar aggregates. The large monomer aggregates are retained by the dialysis membrane and present a potential alternative to small micellar assemblies.     

Rheological properties of multisticker associative polyelectrolytes in semidilute aqueous solutions

Multisticker associative polyelectrolytes of acrylamide (≈86 mol %) and sodium 2‐acrylamido‐2‐methylpropanesulfonate (≈12 mol %), hydrophobically modified with N,N‐dihexylacrylamide groups (≈2 mol %), were prepared with a micellar radical polymerization technique. This process led to multiblock polymers in which the length of the hydrophobic blocks could be controlled through variations in the surfactant‐to‐hydrophobe molar ratio, that is, the number of hydrophobes per micelle (N_H). The rheological behavior of aqueous solutions of polymers with the same molecular weight and the same composition but with two different hydrophobic block lengths (N_H = 7 or 3 monomer units per block) was investigated as a function of the polymer concentration with steady‐flow, creep, and oscillatory experiments. The critical concentration at the onset of the viscosity enhancement decreased as the length of the hydrophobic segments in the polymers increased. Also, an increase in the N_H value significantly enhanced the thickening ability of the polymers and affected the structure of the transient network. In the semidilute unentangled regime, the behavior of the polymer with long hydrophobic segments (N_H = 7) was studied in detail. The results were well explained by the sticky Rouse theory of associative polymer dynamics. Finally, the viscosity decreased with an increase in the temperature, mainly because of a lowering of the sample relaxation time. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 1640–1655, 2004     

Microphase separated structures based on N-substituted polydiallylamines

The ionogenic polymers namely poly(N,N-diallyl-N-cetylammonium hydronitrate) (PDACA · HNO₃) and poly(N,N-diallyl-N,N-dimethylammonium chloride)-block-poly(cetyl acrylate) (PDADMACl-block-PA-16) were synthesized via activation of the terminal double bond of the PDADMACl precursor and initiation of the polymerization of the acrylic monomer in alcohol solution. The microphase separated structure of a blend of both homopolymers and of the block copolymer was proved by differential scanning calorimetry (DSC) and X-ray diffraction measurements. Side chain crystallization in PDA-CA · HNO₃ completely restricts the crystallization of the ionogenic backbones which, however, control the layered structure and the crystallization of the aliphatic chains. In PDADMACl-block-PA-16 crystalline polyacrylate blocks coexist with crystalline ionogenic blocks. The length of the polyacrylate block influences the ability of the ionogenic block to form the crystalline structure.     

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.     

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.     

新型疏水缔合丙烯酰胺/2-苯氧乙基丙烯酸酯共聚物的合成与性质

采用胶束共聚方法合成了一种新型的疏水缔合共聚物 ,它由丙烯酰胺 (AM)和少量的 2 苯氧乙基丙烯酸酯 (POEA) (<1 0mol% )组成 ,具有良好的水溶性 .当溶液浓度超过一定值c 后 ,由于分子间的疏水缔合 ,产生很大的增粘作用 .研究了不同聚合条件下包括单体浓度、投料比和SMR值对聚合物的结构和性能的影响 .实验结果表明 ,聚合物的粘度性质和缔合行为取决于其分子量的大小、疏水单体含量及其嵌段的长度和分布 .     

Preparation and Solution Characteristics of a Novel Hydrophobically Associating Terpolymer for Enhanced Oil Recovery

Hydrophobically associating terpolymers were prepared by the micellar copolymerization technique using acrylamide (AM), 2-trimethylammonium ethyl methacrylate chloride (TMAEMC) as a cationic monomer, and small amounts of 5,5,5-triphenyl-1-pentene (TP<0.5 mol-%) as the hydrophobe. The structure of the copolymer was characterized by FT-IR and ¹H-NMR. The aqueous solution properties of the terpolymers were also investigated as functions of polymer concentration, salinity, temperature and shear rate. The results showed that the thickening behavior of these terpolymers are remarkably dependent on both the number and length of hydrophobic segments in the copolymer chains. As expected, the terpolymers exhibited improved viscosity enhancement properties as the concentration exceeded 0.25 g⋅dL⁻¹, due to intermolecular hydrophobic association. Additional evidence for hydrophobic microdomains was obtained utilizing pyrene-probe fluorescence. Additionally, the ternary copolymers showed favorable salt tolerance, temperature resistance, and recoverable viscosity after shearing.     

Network and thermodynamic properties of hydrogels of poly[1-(3-sulfopropyl)-2-vinyl-pyridinium-betaine]

Samples of poly[1-(3-sulfopropyl)-2-vinyl-pyridinium-betaine] (PSPV) have been synthesized to high conversion by free radical polymerization in aqueous solution of the zwitterionic monomer SPV with several concentrations of the crosslinker N,N′-methylene-bis-acrylamide (MBA). Hydrogels obtained by swelling them in water and aqueous KSCN solution were examined by gravimetric and dimensional analysis, and by compression-strain measurements. The derived effective crosslinking density ν_e was only ca. 11% of the theoretical value, indicating low efficiency of chemical crosslinking by MBA. At 298 K increasing content of MBA produces increases in the values of ν_e, elastic moduli and polymer-water interaction parameter χ. At a fixed MBA content, increasing temperature led to decreases in the values of ν_e, elastic moduli and χ, but an increase in water content of hydrogel. For swelling in aq. KSCN solution the mechanical properties are insensitive to content of salt. Experimental and theoretical analysis afforded values of the water/polymer, salt/water and salt/polymer interaction parameters. Where appropriate the findings are compared with those reported for a different zwitterionic hydrogel and a neutral non-zwitterionic hydrogel.     

Plasma polymerization of some organic compounds and properties of the polymers

Plasma polymerizations (under 13.5-MHz radiofrequency inductively coupled glow discharge) of some organic compounds are investigated by their properties (elemental analysis, surface energy, and infrared spectra) and their relations to the concentrations of free radicals in the polymers as detected by electron spin resonance (ESR) spectroscopy. Monomers that have been investigated are hexamethyldisiloxane, tetrafluoroethylene, acetylene, acetylene/N₂, acetylene/H₂O, acetylene/N₂/H₂O, allene, allene/N₂, allene/H₂O, allene/N₂/H₂O, ethylene, ethylene/N₂, ethylene oxide, propylamine, allylamine, propionitrile, and acrylonitrile. Plasma-polymerized polymers generally contain oxygen, even if the starting monomers do not contain oxygen. This oxygen incorporation is related to the free-radical concentration in the polymer. Molecular nitrogen copolymerizes with other organic monomers such as acetylene, allene, and ethylene, and their properties are very similar to those of plasma-polymerized polymers from nitrogen-containing compounds such as amines and nitriles. The addition of water to the monomer mixture reduces in a dramatic manner the concentration of free radicals in the polymer and consequently the oxygen-incorporation after the polymer is exposed to air. The concentrations of free radicals (by ESR) are directly correlated to the change of the properties of plasma-polymerized polymers with time of exposure to the atmosphere. These changes are primarily the introduction of carbonyl (and possibly hydroxyl) groups. The addition of water to the plasma introduces these groups during the polymerization.     

Dynamic Light Scattering Characterization of a Water-Soluble Terpolymer with Vinyl Biphenyl in Unsalted and Brine Solutions

The sizes and distributions of polymer chains and associating aggregates, hydrophobic associations, and apparent viscosities were investigated with dynamic light scattering (DLS), fluorescence spectroscopy and viscometry for the hydrophobically associating terpolymer poly[acrylamide(AM)/vinyl biphenyl(VP)/sodium 2-acrylamido-2-methylpropane sulphonate(NaAMPS)] (PAAP) in unsalted and brine solutions. The effects of polymer, NaCl concentration, and temperature on the conformation of polymer chains and the formation of associating structures in aqueous solutions were studied. Intra- and inter-molecular hydrophobic associations were formed and the polymer chains were coiled in unsalted solutions below a critical association concentration (C _p *): 0.05 g·dL^?1, and the apparent viscosity was very low and varied slightly with polymer concentration, but a large number of large aggregates were formed because of the presence of dominant intermolecular associations above C _p *, and the apparent viscosity increased abruptly with increasing polymer concentration. The PAAP chains were comparatively expanded (R _h: 21–92 nm) in brine solutions, resulted from the simultaneous incorporation of the bulky pendant side groups, including the biphenyl and 2-acrylamido-2-methylpropane sulphonate groups. With the addition of NaCl, large associative aggregates in unsalted solutions were destroyed to form comparatively expanded mono-macromolecules and smaller aggregates. However, as the NaCl concentration was increased from to 15 to 80 g·L^?1, more large aggregates were again formed, leading to the obvious salt-thickening behavior. The variation of R _h with temperature proved that intermolecular hydrophobic association is an endothermic process.     

Synthesis of high-molecular-weight polyamine by radical polymerization ofN,N-diallyl-N-methylamine

The first synthesis of high-molecular-weight poly(N,N-diallyl-N-methylamine) by thermal (at 30 and 50°C) and photoinduced (at 21 °C) radical polymerization ofN,N-diallyl-N-methylamine (DAMA) in aqueous solution in the presence of an equimolar amount of trifluoroacetic acid (TFA) and by polymerization of the newly synthesized equimolar DAMA·TFA salt is reported. Data of¹H NMR spectroscopy indicate that the molecules of the monomer under chosen conditions are in the protonated form. This leads to a decrease in the contribution of the reaction of degradative chain transfer to the monomer and its transformation into effective chain transfer to the monomer. A bimolecular chain termination mechanism was estabilished and the possibility of controlling the polymerization rate and the molecular weight of the polymer was demonstrated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 430–436, March. 2000.     

Synthesis and characterization of hydrophobically modified polyacrylamides and some observations on rheological properties

Hydrophobically modified polyacrylamide (PAM) polymers were synthesized by means of an aqueous micellar copolymerization, the di-alkyl substituted acrylamides di-n-propylacrylamide (DPAM) and di-n-octylacrylamide (DOAM) being used as hydrophobic comonomers. The number of hydrophobic blocks was varied using three different comonomer contents (f=1, 3 and 5 wt.%). The length of hydrophobic blocks, i.e. the number of hydrophobes per micelle, N_H, was controlled by the sodium dodecyl sulphate surfactant concentration. The effect of the type of hydrophobic comonomer and the number and length of hydrophobic units on the composition of the copolymer and its solubility and rheological properties were studied. The results indicate that the average copolymer composition is independent of the degree of conversion and surfactant concentration. Solubility and rheological measurements lead to a number of conclusions. First, DPAM is a weak hydrophobic monomer, all DPAM/AM (AM=acrylamide) copolymers being water soluble. Second, there is no strong hydrophobic interaction between DPAM units, in particular for low polymer concentration and N_H, and thus no strong associative thickening behaviour. Third, DOAM is a strong hydrophobic comonomer. Incorporation of a small amount of DOAM into PAM causes a dramatic enhancement in viscosity due to hydrophobic interactions. The properties of the copolymers are strongly dependent on the N_H values, most DOAM/AM copolymers being insoluble in water.     

Effect of filler networking on the response of thermosensitive composite hydrogels

Several composite hydrogels of poly(N-isopropylacrylamide) (pNIPAAm) with sodium montmorillonite (NaMM) have been synthesized using a fixed polymer/NaMM ratio (4:1 wt./wt.), but various monomer concentrations, in order to obtain hydrogels with different degrees of swelling, and thus different clay contents in the swollen state. For comparison, unfilled pNIPAAm gels have been also prepared at the same concentrations. The equilibrium swelling behaviour of the gels has been studied both in the swollen and in the shrunk state. In the swollen state, the polymer volume fraction increases with the initial monomer concentration C₀. In the shrunk state, the polymer fraction in pNIPAAm hydrogels is dependent on the specimen size and on C₀, whereas in the composite gels a constant polymer content is observed. When subjected to stepwise heating from 25 to 45 °C, unfilled gels undergo only poor deswelling. By contrast, complete deswelling takes place in composite gels. The latter show half-shrinking times varying over two orders of magnitude, depending on the monomer concentration and on the procedure followed to disperse NaMM, which determine the overall dispersion state of the filler, as evidenced by transmission electron microscopy (TEM). In particular, TEM observations show clay networking above a percolation threshold near 2.5 wt.% of NaMM. The effect of the incorporation of clay on the response to thermal stimuli is discussed in terms of the ability of NaMM to hinder the hydrophobic association of pNIPAAm segments and in terms of its dispersion state. It is suggested that, above the percolation threshold, NaMM forms a hydrophilic, physical network, through which water can flow also above the volume transition temperature, where pNIPAAm acquires a hydrophobic character.     

Immobilization of microbial cells by radiation-induced polymerization of glass-forming monomers and immobilization ofStreptomyces phaeochromogenes cells by polymerization of various hydrophobic monomers

The immobilization ofStreptomyces phaeochromogenes cells was studied by the radiation-induced polymerization of various hydrophobic glass-forming monomers at low temperatures. The glucose isomerase activity of cells immobilized in hydrophobic polymers showed no decrease in activity with repeated use (batch enzyme reaction). Activity increased with increasing monomer concentration in contrast to results with the immobilized enzyme. The hydrophobic polymer composite was microspheric in form. The particle diameter of the composite increased with the increasing monomer concentration.K _m values of the immobilized cells were close to that of intact cells. It was deduced that the cells were trapped on the surface part of the hydrophobic polymer ready to react with the substrate, and not within the matrix where diffusion would play an important role in reaction rates.     

Magnetic hollow poly(N-isopropylacrylamide-co-N,N′-methylenebisacrylamide-co-glycidyl acrylate) particles prepared by inverse emulsion polymerization

To prepare functionalized magnetic polymer particles that are thermally responsive, inverse emulsion copolymerization of N-isopropylacrylamide, N,N′-methylenebisacrylamide and glycidyl acrylate (GA) was investigated in paraffin oil in the presence of γ-Fe₂O₃ nanoparticles dispersed in a water/glycerol mixture. The resulting polymer particles were characterized regarding the morphology, size, polydispersity, iron content, and the temperature-dependent phase transition using optical microscopy, transmission electron microscopy, scanning electron microscopy, atomic absorption spectroscopy, and differential scanning calorimetry. Magnetic properties were examined using hysteresis loop measurements and by analyzing the magnetic susceptibility with respect to temperature. We have also investigated the influence of the concentration of γ-Fe₂O₃ and GA in monomers on properties of the particles (morphology, size, and presence of oxirane groups). The particles possessed a hollow structure as a result of phase separation between water/glycerol hydrophilic solvents in the polymerization feed and the forming polymer. Depending on the concentration of γ-Fe₂O₃ in the monomer phase, the magnetic hollow particles contained 5–24 wt% iron. In water, the particles gradually collapsed when the temperature was raised to 40 °C because the elevated temperature weakened hydration and the PNIPAAm chains gradually became more hydrophobic.     

Optically active polymeric salts prepared from amino acids and polysulfonylpyrrolidinium chloride

Possibility of preparing optically active polymers from N,N-diallyl-N,N-dimethylammonium chloride-sulfur dioxide copolymer and optically active acids was studied by the ion-exchange method.     

Synthesis and solution properties of amphiphilic cycloterpolymers of 1,1-diallyl-4-formylpiperizinium chloride, diallyloctadecylammonium chloride and sulfur dioxide

The cycloterpolymerizations of hydrophilic monomer (1,1-diallyl-4-formylpiperizinium chloride) with hydrophobic monomer (diallyloctadecylammonium chloride) and sulfur dioxide in dimethyl sulfoxide using azobisisobutyronitrile (AIBN) as the initiator afforded a series of water-soluble monocationic polyelectrolytes (MCPEs) in well over 90% yields. Acidic (HCl) hydrolysis of the N-formyl groups in MCPEs to NH₂⁺Cl⁻ groups gave the dicationic polyelectrolytes (DCPEs), which on treatment with one equivalent of NaOH furnished the basic cationic polyelectrolytes (BCPEs) containing basic as well as quaternary nitrogens. The solution properties of the resultant series of interconverting polyelectrolytes (MCPE → DCPE ↔ BCPE) were investigated by viscometric techniques. The polymer concentration C∗_HA of 0.2 g/dL was required for the manifestation of hydrophobic associations in a MCPE containing 4.5 mol% octadecyl pendents. The DCPEs exhibited sharp increase in viscosity in salt (NaCl)-added solution as compared to salt-free water. The pH-responsive BCPE is shown to demonstrate better associative properties in the absence of HCl; upon addition of HCl, the charge density increases in the polymer chains thereby resulting in increased electrostatic repulsions and decreased associations. Polymer-surfactant interactions were investigated using cationic surfactant cetyltrimethylammonium chloride (CTAC); tremendous increase in the viscosity values of the DCPE was observed in the presence of the surfactant.