Dilute solution properties of anionic poly(potassium-2-sulphopropylacrylate)

The dilute solution properties of an anionic polyelectrolyte, poly(potassium-2-sulphopropylacrylate) (poly(SPA)) are studied by measurements of intrinsic viscosity, degree of binding, ionic strength and critical micelle concentration. The intrinsic viscosity of this polyelectrolyte is related to the type and concentration of the salt added. The intrinsic viscosity behaviour of an anionic polyelectrolyte resulting from the electrostatic repulsive force of the polymer chain is in contrast to that of a polyampholyte. The polyelectrolyte in high concentration of NaCl has a low degree of binding, indicating that the proton ion (H⁺) is relatively difficult to bind to the sulphonate group (SO⁻₃) at the polymer end. An increase in ionic strength causes the pK_a to decrease at the half-neutralization point. The monomer solutions exhibit a plot typical of those observed for detergents, with a break in the curve occurring at the critical micelle concentration. For the polymer solutions, no break in the equivalent conductance curve was found for the concentrations studied.     

Dilute solution properties of poly(benzyl methacrylate)

A series of fractions of poly(benzyl methacrylate) have been prepared with weight-average molecular weights ranging from 0.19 × 10⁶ to 1.74 × 10⁶ g/mol. A theta temperature of 73.2°C was obtained from phase separation studies in cyclopentanol. Intrinsic viscosities have been measured in toluene and methyl ethyl ketone over a range of temperatures, as well as under theta conditions. Unperturbed dimensions and their temperature coefficient have been determined by a number of procedures. A value for the polymer solubility parameter has been calculated from the enthalpy parameter obtained from phase separation data.     

Dilute solution properties of randomly branched poly(methyl methacrylate)

Randomly branched poly(methyl methacrylate) samples were prepared by copolymerization with different amounts of ethylene dimethacrylate. The molecular weight distributions, radius of gyration distributions, and intrinsic viscosity distributions were measured by size exclusion chromatography with refractive index, multiangle light-scattering, and viscosity detectors. The effect of branching on the radius of gyration was compared with the effect on the intrinsic viscosity. It was found that the intrinsic viscosity contraction factor gⁱ scales with the radius of gyration contraction factor g, with the exponent, ϵ, having a value in the range 0.8–1.0. © 1996 John Wiley & Sons, Inc.     

Dilute solution properties of poly(2-methoxycyanurate) of bisphenol F and bisphenol A

Poly(2-methoxycyanurate) of bisphenol F and bisphenol A (PMCBFA) was synthesized and fractionated by a fractional precipitation method. The fractions were characterized by viscometry, osmometry and gel permeation chromatography. The Mark–Houwink–Kuhn–Sakurada (MHKS) parameters were established in four solvents and at four different temperatures. The unperturbed dimensions and their coefficients in different solvents were computed using the Stockmayer–Fixman excluded volume theory. From the solution study it was found that PMCBFA is highly flexible. This may be due to the ether linkage present in the main chain.     

Dilute solution properties of poly(3-dimethyl acryloyloxyethyl ammonium propiolactone)

The aqueous solution properties of an ampholytic poly(3-dimethylacryloyloxyethyl ammonium propiolactone), poly(DMAEAPL), are examined in this study by measuring reduced viscosity, intrinsic viscosity, degree of binding and dynamic light scattering. This polyampholyte's intrinsic viscosity is related to the type and concentration of the salt added. The intrinsic viscosity behaviour for the polyampholyte resulting from the associations of the polymer chains is in contrast with cationic and anionic polyelectrolyte. The polyampholyte in high concentration of NaCl has a low degree of binding, indicating that the proton ion (H⁺) has difficulty in binding to the carboxylate group (COO⁻) at the polymer end. The carboxybetaine, DMAEAPL, has a higher degree of binding than the corresponding sulfobetaine, DMAPS. Dynamic light scattering measurements indicate that the poly(carboxybetaine) diffusion coefficients decrease and the chain dimensions increase with an increasing salt concentration. The models proposed in this study can account for the poly(DMAEAPL) solution viscometrics and the degree of binding. © 1997 Elsevier Science Ltd.     

Dilute solution properties of cationic poly(dimethyl sulfate quaternized dimethylaminoethyl methacrylate)

The dilute solution properties of a cationic polyelectrolyte, poly(dimethyl sulfate quaternized dimethylaminoethyl methacrylate) [poly(DMAEM · C₂H₆SO₄)], are studied by measurements of intrinsic viscosity, degree of binding, and flocculation application. The intrinsic viscosity of this polyelectrolyte is related to the type and concentration of added salt. The intrinsic viscosity behavior for cationic polyelectrolyte resulting from the electrostatic repulsive force of the polymer chain is contrasted with polyampholyte. The polyelectrolyte in the presence of KCl has a lower degree of binding, indicating that the proton ion (H⁺) is relatively difficult to bind to the CH₃SO₄^? at the polymer end. The polymerization of DMAEM · C₂H₆SO₄ in 0.5M KCl aqueous solution proceeded more easily than that of DMAEM · C₂H₆SO₄ in pure water. The polymerization rate of DMAEM · C₂H₆SO₄ is found to pass through an extreme value as a function of pH. Optimum flocculation, corresponding to the complete removal of turbidity in the supernatant, is achieved. Beyond the optimum flocculation, high polymer dosages redisperse the bentonite suspensions.     

Poly(sulphopropylbetaines): 2. Dilute solution properties

Solution properties of a series of aromatic ($\text{5 × 10}{}^3\text{<}\text{M}\text{?}{}_{\mathrm{w}}\text{< 2.5 × 10}{}^5$) and aliphatic ($\text{10}{}^6\text{<}\text{M}\text{?}{}_{\mathrm{w}}\text{< 1.2 × 10}{}^7$) poly(sulphopropylbetaines) have been investigated by examining three complementary phenomena: (a) solubility in organic protic solvents; (b) water solubility promoted by various (cloud point titrations), with special emphasis on the influence of the anion polarizability and a comparison between Na⁺ and Ca⁺⁺; (c) hydrodynamic and morphological properties in aqueous NaCl solutions at 25°C, as derived from the Mark-Houwink-Sakurada relations. Chain expansion is a slightly increasing function of the NaCl concentration (≤1 M) but it remains, however, relatively low, even for high molecular weights (α_η < 1.15). With respect to the polymeric amino precursors, the zwitterionic group

enhances chain rigidity (steric factor σ), as a result of its steric hindrance and specific dipolar interactions between neighbouring units.     

Nucleophilic substitution onto poly(methylmethacrylate): 4. Dilute solution properties of substituted polymethacrylates

The morphological and hydrodynamic properties of a series of homogeneous fractions of substituted poly(methylmethacrylate) (A units) bearing keto-β-functional groups (B units) of the general structureCOCH₂R, with R = SO_xCH₃ (x = 1,2) or SO₂N(CH₃)₂, were investigated by intrinsic viscosity, light scattering and partial specific volume measurements in dimethylformamide (DMF) solution at 25°C. For molar substitution degrees $\text{DS}{}_{\mathrm{m}}\text{< 0.5}$, the copolymers behave as flexible random coils. The Stockmayer-Fixman-Yamakawa analysis of the $\text{[η]-}\text{M}\text{?}{}_{\mathrm{w}}$ data leads to slightly higher unperturbed dimensions K_o and steric factor σ than those for PMMA, and to stronger chain expansion as a result of the weak hydrogen bonding between DMF and COCH₂R units and a positive X_AB interaction parameter. For $\text{DS}{}_{\mathrm{m}}\text{> 0.5}$ however, copolymers bearing COCH₂SO₂N(CH₃)₂ groups behave as worm-like chains, as derived from the Fujii-Yamakawa analysis of the $\text{[η]-}\text{M}\text{?}{}_{\mathrm{w}}\text{-}\text{v}\text{?}$ data: the persistence length increases from 380 to 570 Å within the $\text{DS}$_m range 0.57–0.75. This transition from a random coil to a worm-like chain for $\text{DS}{}_{\mathrm{m}}\text{> 0.5}$ was tentatively correlated with the accumulation of B units in sterically hindered and self-associated short blocks of average length l_B ? 1.6 which provide drastically increased rigidity to the copolymer chain.     

Dilute solution properties of naphthalene-labeled cationic poly(dimethyl sulfate quaternized acrylamide/N,N-dimethylaminopropylmaleimide copolymer)

The properties of a novel cationic, naphthalene-labeled cationic poly(dimethyl sulfate quaternized acrylamide/N,N-dimethylaminopropylmaleimide copolymer), poly-(DSQADMAPM)/NA in aqueous solution are examined in this study, measuring intrinsic viscosity, reduced viscosity, and ionic strength. This cationic poly(DSQADMAPM)/NA’s intrinsic viscosity is dependent on the type and concentration of salt added to the aqueous solution. The intrinsic viscosity behavior of the cationic poly(DSQADMAPM)/NA resulting from the electrostatic repulsive force of the polymer chain is contrasted with polyampholyte. Smaller anions such as F⁻ with a common cation (K⁺) are found to be the most difficult to be bound to the end group, indicating that a higher intrinsic viscosity of the poly(DSQADMAPM)/NA would be in KF salt aqueous solution. Smaller cations such as Li⁺ with a common anion (Cl⁻) are found to be the most difficult to be bound to the quaternary ammonium group, indicating that a higher intrinsic viscosity of the poly(DSQADMAPM)/NA would also be in LiCI salt aqueous solution. Models are proposed to account for the poly(DSQADMAPM)/NA solution viscometrics.     

Dilute solution viscosity properties of high molar mass poly(acrylonitrile‐co‐itaconic acid)

The intrinsic viscosities [η] and viscosity constants of high molar mass poly(acrylonitrile‐co‐itaconic acid) copolymer in DMF were obtained by the methods of Huggin, Fuoss, Martin and Schulz‐Blaschke. The values of [η] by averaging procedures suggested by Sakai were close to those from Huggins method. There was an abnormal positive deviation from the rectilinearity of the reduced viscosity (η_red) versus concentration (c) plot in all the cases in the dilute regime, which was attributed to the polyelectrolytic effect. This was further confirmed by the analysis by Fuoss method. The deviation from the Huggins dependence is discussed for a good solvent (DMF) alone and in the presence of a non‐solvent, methanol. The deviation cross‐over points c′ and c″ changed with molecular weight, and the concentration range greater than c″ and less than c* was taken for a more reliable determination of intrinsic viscosity. The non‐solvent played a key role in determining the polymer–polymer interactions. The Huggins coefficient increased and the cross‐over points c′ and c″ shifted to higher concentration regime as the mixed solvent became poorer. The inter‐ and intra‐polymer interactions increased in the presence of methanol. In poor solvent, the enhanced intramolecular interactions caused the polymer to shrink in size, causing a reduction in [η] and hydrodynamic volume. Copyright © 2003 Society of Chemical Industry     

Dilute solution properties of hydroxyethyl starch

The dilute solution properties of hydroxyethyl starch (HES) were examined by using the techniques of osmometry, light scattering, and viscometry. The molecular weight range was approximately 2 × 10⁶–0.06 × 10⁶. Since HES is a branched molecule, its properties were compared with those of two linear counterparts, ethyl hydroxyethyl cellulose and hydroxyethyl cellulose. The branching index g was estimated to be about 0.3 when calculated from the intrinsic viscosity, radii of gyration, and second virial coefficients.     

Dilute solution properties of methyl methacrylate—acrylonitrile copolymer (MA1)

This paper deals with studies on the dilute solution properties of methyl methacrylate—acrylonitrile copolymer of 0.289 mole fraction (mf) of acrylonitrile composition. Mark—Houwink parameters for this copolymer have been evaluated in acetonitrile (MeCN), 2-butanone (MEK), dimethylformamide (DMF) and γ-butyrolactone (γ-BL). The solvent power is found to be in the order of MEK < MeCN < DMF < γ-BL at 30°C. Herein, probably for the first time, the steric factor for the copolymer is found to be lower than that for the parent homopolymers and the excess interaction parameter, χ_AB is found to be negative. This probably suggests that the units are compatible to each other.     

Molecular weight distributions and solution properties of poly(2-trimethylammoniumethyl methacrylate chloride)

Solution properties of the cationic polyelectrolyte poly(2-trimethylammoniumethyl methacrylate chloride), PTMAC, in aqueous sodium chloride solutions of varying ionic strength were investigated with unfractionated samples in the molecular weight range 7, 7 × 10³ ≤ M?_W ≤ 1, 1 × 10⁷ by light scattering, viscometry, and sedimentation velocity analysis. Molecular weight distributions were determined by size exclusion chromatography and sedimentation velocity experiments. The influence of polydispersity on static and dynamic solution properties was eliminated by appropriate correction procedures. The results show that solutions of PTMAC in 1 n NaCl can be essentially treated like those of uncharged polymers in organic solvents with classical theories.     

Aqueous solution properties of a poly(vinyl imidazolium sulphobetaine)

In this investigation the aqueous solution properties of an ampholytic poly(vinyl imidazolium sulphobetaine) are discussed. This class of polymer is water insoluble and its solubilization is related to the type and concentration of added salt. Cloud point determinations, intrinsic viscosity and light scattering studies are presented to illustrate the solution behaviour of this polyampholyte as a function of the type of cation and anion present. An explanation of its solubility in certain salt solutions is presented.     

Synthesis and solution properties of a new poly(electrolyte-zwitterion)

A novel electrolytic-zwitterionic (EZ) monomer, Sodium N-(3-sulfopropyl)-3-(N,N-diallylamino)propanesulfonate, on homopolymerization in aqueous solution using tert-butylhydroperoxide, afforded the poly(electrolyte-zwitterions) (PEZ). The copolymer of the above monomer and sulfur dioxide was also synthesized in excellent yield. The EZ monomer as well as the PEZs contains structural features common to both polyzwitterions and conventional polyelectrolytes. The solution properties of these polymers were studied in detail. The PEZ, as the name implies, possess dual type of structural character and it is the electrolytic portion of the structure that dictates the solubility and viscosity behavior of the polymers.     

CaCl2对聚间二苯砜对苯二甲酰胺/DMF溶液特性的影响

为了研究CaCl₂对聚间二苯砜对苯二甲酰胺(mt-PSA)在DMF中分子构象和形态的影响,采用流变仪测定了mt-PSA/DMF/CaCl₂浓溶液的流变行为,并通过乌氏黏度计和激光光散射研究其稀溶液的溶液黏度和高分子形态尺寸。结果表明:CaCl₂的加入增大了大分子与溶剂在mt-PSA/DMF/CaCl₂浓溶液和其稀溶液中的相互作用,同时CaCl₂使大分子链段得到舒展。但大分子的重均分子量没有发生明显的变化,说明CaCl₂未使mt-PSA高分子链段发生聚集或者坍塌。     

Viscosity properties of aqueous solution of poly(allylamine)-metal complexes

Poly(allylamine)-metal complexes with Co(II), Cu(II), and Ni(II) in conjunction with an ultrafiltration membrane were prepared. They were obtained varying the polymer/metal ion ratio and the pH (1, 3, 5, 7).     

Aqueous solution properties of poly(trimethyl acrylamido propyl ammonium iodide) [poly(TMAAI)]

The aqueous solution properties of a cationic poly(trimethyl acrylamido propyl ammonium iodide) [poly(TMAAI)] were studied by measurements of reduced viscosity, intrinsic viscosity, and flocculation test. The reduced viscosity and intrinsic viscosity of this cationic polyelectrolyte were related to the types and concentration of added salt. “Soft” salt anions were more easily bound on the quaternary ammonium (R₄N⁺) of poly(TMAAI) than those of “hard” salt anions. Halide anions are hard anions; consequently, hard cations were more easily attracted to halide anions for reducing the binding degree of halide anion on the quaternary ammonium group (R₄N⁺). Some salt ions were observed to strongly attract the quaternary ammonium of the cationic polymeric side chain for coagulation of the polymers. This effect would make the polymeric aqueous solution become turbid. The intrinsic viscosity behavior for cationic polyelectrolyte resulting from the electrostatic repulsive force of the polymer chain is contrasted with polyampholyte. A comparison of various flocculants as to the effect of flocculation was also studied. © 1994 John Wiley & Sons, Inc.     

Dilute solution properties of carboxymethylchitins in high ionic-strength solvent

The hydrodynamic characteristics in aqueous solution at ionic strength I=0.2  of carboxymethylchitins of different degrees of chemical substitution have been determined. Experimental values varied over the following ranges: the translational diffusion coefficient (at 25.0°C), 1.1<10⁷×D<2.9 cm² s⁻¹; the sedimentation coefficient, 2.4<s<5.0 S; the Gralen coefficient (sedimentation concentration-dependence parameter), 130<k_s<680 mL g⁻¹; the intrinsic viscosity, 130<[η]<550 mL g⁻¹. Combination of s with D using the Svedberg equation yielded ‘sedimentation–diffusion' molecular weights in the range 40 000<M<240 000 g mol⁻¹. The corresponding Mark–Houwink–Kuhn–Sakurada (MHKS) relationships between the molecular weight and s, D and [η] were: [η]=5.58×10⁻³ M^0.94; D=1.87×10⁻⁴ M^−0.60; s=4.10×10⁻¹⁵ M^0.39. The equilibrium rigidity and hydrodynamic diameter of the carboxymethylchitin polymer chain is also investigated on the basis of wormlike coil theory without excluded volume effects. The significance of the Gralen k_s values for these substances is discussed.