Abstract: A method for preparing microcapsules comprising polymerizing urea and formaldehyde in the presence of an anionic polyelectrolyte and an ammonium salt of an acid and forming a wall membrane of a urea/formaldehyde resin around droplets of a hydrophobic oily liquid.

Abstract: A change in electrodialytic transport properties of various cation exchange membranes was observed after the membranes had been adsorbed or ion-exchanged with various cationic polyelectrolytes. Transport properties measured in this report were the relative transport number of calcium ion to sodium ion PCaNa, the current efficiency of cations, and the electric resistance of the membrane during the electrodialysis. Weakly basic and strongly basic cationic polyelectrolytes of various molecular weights were used. Though PCaNa of any cation exchange membrane decreased by the adsorption or ion exchange of any cationic polyelectrolyte, the degree of the decrease in PCaNa changed with species and molecular weight of polyelectrolytes and species of cation-exchange membranes. Weakly basic polyelectrolytes and low molecular weight, strongly basic polyelectrolytes were effective in producing a marked decrease in PNaCa of any cation exchange membrane. The effect of strongly basic polyelectrolytes of high molecular weight on PCaNa was weak in most cases. However, if it was possible to make the polyelectrolyte adhere to the surface of the membrane to form a compact coiled structure, any cationic polyelectrolyte was effective in producing a remarkable decrease in PCaNa of any cation-exchange membrane.

Abstract: Flow field-flow fractionation (flow FFF) is introduced as a chromatographic-like method with a potential for separating and characterizing water soluble polymers. The theory of the method is summarized, showing that one gets a size distribution curve based on the Stokes diameter, d. Problems in interpreting the elution profile in both flow FFF and gel permeation chromatography are discussed in the light of complications arising from electrostatic chain expansion in polyelectrolytes. The experimental approach is described using a channel of 2.00 ml volume. Sulfonated polystyrenes of three different molecular weights are separated from one another with and without added salts. The dependence of retention on sample size is shown to be least in the salt solution, indicating that this is most suitable for analytical work. The sodium salts of polyacrylic acid are also investigated. Distinct elution profiles are noted for two of these polydisperse polymers. Size distribution curves for the 2,000,000 MW ...

Abstract: The equilibrium thicknesses and drainage have been measured of free liquid films, stabilized only by poly(vinylalcohol)(PVA) or partially esterified poly(methacrylic acid)(PMA-pe). The equilibrium thickness of PVA-films considerably exceeds twice the ellipsometric or the hydrodynamic thickness of one adsorbed layer. This is attributed to the dominant steric repulsion of isolated tails, a conclusion that is substantiated by theoretical arguments. The change in drainage behaviour of PMA-pe films as a function of pH correlates well with the conformational transition that this polyelectrolyte undergoes in the bulk and in the adsorbed state.

Abstract: Kinetic theories of crystallization of polymers do not apply to high supercooling. The thickness of the crystalline lamellae becomes independent of the crystallization temperature and is a characteristic parameter of the polymer. We relate this limiting thickness to the flexibility of the polymer chain in the pure liquid or in solution before crystallization. The folded chain in the crystalline state is analogous to the coiled chain before crystallization. Flexibility and limiting thickness depend in a similar way on the solvent, defect concentration in the polymer chains, pressure, pH, and salt concentration in case of crystallization of polyelectrolytes. Folded chains appear also in oligomer crystals when the oligomers have a coiled shape in the liquid state. The limiting fold period of crystalline polymers and oligomers is found to be an order of magnitude greater than the persistence length of the Gaussian chain in the liquid state.

Abstract: Mixing of chitosan with sodium carboxymethyldextran having opposite charge gave rise to the formation of novel water-insoluble precipitates. The mole ratios of N/COO− in the polyelectrolyte complexes thus prepared were estimated to be 0.248–1.658. It was found that pH, mole ratio of N/Na and the order of mixing play an important role in determining the composition ratio of N/COO− in the polyelectrolyte complexes. IR spectroscopic studies, blood clotting test, elementary analyses, the color reaction with Toluidine Blue and studies on solubility of polyelectrolyte complexes revealed that there is no noticeable interactions between –COOH groups and –OH groups. However, the –NH3+ groups in chitosan participate in the binding with carboxymethyldextran, probably through its –COO− groups, in the polyelectrolyte complexes. It seems that the number of binding sites between –NH3+and -COO− groups in the polyelectrolyte complexes at pH 3.0 is smaller than those prepared at pH 6.5. Both the polyelectrolyte complexes p...

Abstract: The invention related to a heterogeneous cation exchange membrane comprised of particles of sulfonated polyphenylene sulfide polyelectrolyte in a fluorocarbon polymeric binder and to the method of making the same.

Abstract: For a number of weak polyelectrolytes potentiometric titration data are interpreted on the basis of the dependence of the pK on the degree of ionization σ by considering the separate contributions for a) the mean electrostatic potential field, b) interactions between neighbouring functional groups, c) the distribution of the functional groups over the macromolecule, d) specific conformational aspects and branching. For the various polyelectrolytes this procedure leads at low ionic strength to a satisfactory picture of the charging process. However, on increasing the ionic strength definite discrepancies between the two weak polybases with strong neighbour interactions, poly(ethylene-imine) and poly(vinylamine), and the other polyelectrolytes are found. The very strong dependence of pK on σ in these two cases even at high ionic strength can only be explained by concluding that the electrostatic potential at the site of reaction in these molecules is much higher than expected on the basis of additivity of the various specific effects.

Abstract: The study of semi-dilute polyelectrolyte solutions by small-angle neutron scattering shows that the correlation function S(q) of all the chains presents a peak for a value q = qh of the scattering vector q. This is taken as evidence for some organization among the elongated polyions. This phenomenon has been observed for a fraction of polymethacrylic acid of very low molecular weight. The experiments show essentially: (1) the progressive vanishing of the peak with the addition of a neutral salt at constant polyelectrolyte concentration; (2) the variation of qh with the polyelectrolyte concentration c, qh ∝ c1/2; (3) the decrease of the peak intensity as the charge density of the chain increases. These results, which indicate the important role of the electrostatic interactions on this organization phenomenon, are discussed in terms of a lattice model and a recently proposed isotropic model.

Abstract: Conformaitons of poly(L-arginine)/polyanion complexes were studies by CD measurements. The polyanions were the homoplolypeptides poly(L-glutamic acid) and poly(L-aspartic acid); the synthetic polyelectrolytes and polyethylenesulfonate; and the polynucleotides were native DNA, denatured DNA, and poly(U). It was found that poly(L-arginine) forms the α-helical conformation by interacting with the acidic homopolypeptides and the synthetic anionic polyelectrolytes. In each complex, poly(L-glutamic acid) is in the α-helical conformation, whereas poly(L-aspartic acid) is mostly in the random structure. The poly(L-glutamic acid) complex changed into the β-sheet structure at the transition temperature about 65°C in 0.01M cacodylate buffer (pH 7). Even in the presence of 5M urea, this complex remained in the α-helical conformation at room temperature. The existence of the stable complex of α-helical poly(L-arginine) and α-helical poly(L-glutamic acid) was successfully supported by the model building study of the complex. The α-helix of poly(L-arginine) induced by binding with polyacrylate was the most stable of the poly(L-arginine)-polyanion complexes examined as evidenced by thermal and urea effects. The lower helical content of the polyethylenesulfonate-complexed poly(L-aginine) was explained in terms of the higher charge density of the polyanion. On the other hand, native DNA, denatured DNA, and poly(U) were not effective in stabilizing the helical structure of poly(L-arginine). This may be due to the rigidity of polyanions and to the steric hindrance of bases. Furthermore, the distinitive structual behavior of poly(L-arginine) and poly(L-lysine) regarding polyanion interaction has been noticed throughout the study.

Abstract: An investigation of the conditions for monolaver or multilayer formations of cationic polyelectrolyte on cellulose fibers using adsorption, hydrodynamic permeability, and electrokinetic measurements is described. ζ-potential measurements by streaming current method were made on polymer-treated fiber pads. Monolayer formations on cotton linter (CT) fibers and dissolving pulp (DP) and multilayer formation on carboxymethyl cellulose (CMC) fibers were demonstrated. Monolayer formation proceeds by electrostatic interaction and Van der Waals force until all the negative charges of the fibers are neutralized. After charge neutralization, adsorption proceeds by Van der Waals force until formation of a saturated monolayer is completed. Multilayer formation proceeds mainly by electrostatic force until all the carboxyls of the fibers are neutralized. The presence of excess negative charge due to unneutralized carboxyls at the point of monolayer formation on CMC is the prerequisite for further adsorption to form a saturated multilayer. Affinity of the interactions, configurations of the adsorbed polymer chains, thickness of monolayer and multilayer, the effect of polymer molecular weights, and the stoichiometry of charge neutralization are discussed. A multilayer adsorption model is proposed to account for the experimental data.

Abstract: Case 1-11308/+ Canada PROCESS FOR PRODUCING SIZED PAPER AND CARDBOARD WITH POLYELECTROLYTES AND EPOXIDE-AMINE-POLYAMIDE REACTION PRODUCTS Abstract of the Disclosure A process for producing paper or cardboard sized in the pulp with epoxide-amine-polyamide reaction products is disclosed. This process comprises adding to the fibre suspension, which has a pH value of 5 to 8, (A) at least one water-soluble higher molecular poly-electrolyte, which is cationic if the pH value of the fibre suspension is 6.5 to 8 and anionic if the pH value of the fibre suspension is 5 to 7, followed by (B) at least one water-soluble or water-dispersible salt of an epoxide-amine-polyamide reaction product, and further processing the fibre suspension into the form of paper or cardboard.

Abstract: In water and waste treatment, cationic polyelectrolytes can function as either primary coagulant or coagulant aid because they are positively charged. It has been known that most of the colloidal and suspended impurities in natural water have negative surface charges. Cationic polyelectrolyte will neutralize the impurities or pollutants, then agglomerate them into larger masses for rapid solid-water separation by sedimentation, flotation, centrifugation, filtration, or reverse osmosis. Anionic polyelectrolyte are negatively charged and function as coagulants in water and waste treatment. They must be applied along with positively charged coagulants which neutralizes the negative charge on the colloidal and suspended impurities. In a water softening process, where precipitation particles are positively charged, however, anionic polyelectrolytes alone can coagulate. Nonionic organic polymers, however, can only function as coagulant aids which should be introduced at a point shortly after flocculation first occurs. Nonionic polymers will coat the existing floc particles so that when the flocs collide, they will adhere to one another, thus forming larger and heavier masses.

Abstract: Electrodialytic transport properties of cation exchange membrane are changed by adhesion of polyethylene imine on the membrane surface The effect of conformation of polyethylene imine molecules on the transport properties of the membrane, thickness of adherent layer and mechanism of adhesion were discussed Observed were relative transport numbers of calcium ions to sodium ions,P Na Ca , current efficiency, electric resistance of the membrane during electrodialysis and pH-shift of anolyte after electrodialysis

Abstract: The neglect of chain flexibility in Manning's theory of polyelectrolytes is assessed. For a flexible polyelectrolyte-the uniformly charged wormlike chain-counterion condensation is unaffected but colligative properties need to be modified. The relevant dimensionless parameter is (κLT)-1 where κ-1 is the Debye-Huckel radius and LT is the sum of the bare and electrostatic persistence lengths.

Abstract: The solution of charged sodium dextran sulfate (molecular weight 6000) co-reacted with that of oppositely charged chitosan to form a water-insoluble hydrous complex, whose clot-inhibiting property was sensitive to such reaction conditions as the order of mixing, the kind of acid species used for the adjustment of pH, and the concentration of hydrogen ion at which the preparation of polyelectrolyte complex was carried out, although all the polyelectrolyte complexes were prepared from the same starting materials. In order to clarify the relationship between the molecular conformation of the polyelectrolyte complex and its clot-inhibiting property, ir spectroscopic studies, in vitro blood-clotting tests, color reaction with toluidine blue, elemental analyses, and so on, were performed. Consequently, it was suggested that the polyelectrolyte complexes consisting of sodium dextran sulfate of lower molecular weight are more clot-inhibiting than those with higher molecular weight. It was also found that polyelectrolyte complexes prepared under the mixing order of sodium dextran sulfate solution added to chitosan solution are also more clot-inhibiting than those prepared under the reverse mixing order, chitosan solution added to sodium dextran sulfate solution. Furthermore, it has become apparent that the anticlotting polyelectrolyte complexes have some characteristic ir absorption bands, and that they displayed color reaction with toluidine blue. A new possibility may be anticipated from our experimental results, providing important information relating to realizing a functional polymer, antithrombogenic material, whose property may be ordered.

Abstract: A study has been made of the properties of polyelectrolyte complexes (PEC) of nonequimolar composition as exemplified by those formed by poly(N-ethyl-4-vinyl-pyridinium bromide) (PVP C2H5Br) and polymethacrylic acid (PMAA) in acid media. It has been found that such PEC have a property in common in that they dissolve in neutral and weakly basic media, whereas simple mixing of polyelectrolytes in any ratios at pH at which both polymer components are completely charged (pH ≈ 7) leads only to formation of equimolar PEC that are insoluble in water. The dissolution of PEC is observed over a sufficiently wide composition range 2·5 < PVPB:PMMA < 5, and does not involve dissociation of PEC into components. The mechanism of formation of water-soluble polycomplexes is considered, and a model of such polycomplexes is suggested.

Abstract: Kinetic studies of the pH-induced conformational transition of the hydrophobic copolyelectrolyte of maleic acid and styrene in aqueous NaCl at ionic strength 0.09 were performed by an optical method at 25.0°C with a rapid reaction analyzer of high resolving power. A pH jump applied to a solution, in which the molecule is in the compact form, gives a kinetic trace from which, by appling the general kinetic theory of cooperative transitions, two mean relaxation times are determined. Plots of these relaxation times against the degree of ionization of the primary carboxyl groups of the maleic acid units agree well with theoretical predictions from the linear Ising model, where the molecule in the compact form is described as a random coil with hydrophobic “pockets.” The initiation parameter for a pocket obtained from the kinetic data is 0.036. On the other hand, the parameter calculated from the previous pH-titration results by applying Zimm–Rice theory is 0.015 at the ionic strength 0.09 and 25.0°C. Such values are compared with those determined from pH-titration data on other hydrophobic polyelectrolytes.

Abstract: Polymers comprising quaternary phosphonium counter-ion salts of acids having anionic groups covalently bonded to carbon atoms comprising a backbone chain of a polymer, or to acrylic, alicyclic or aromatic radicals which are pendant to the backbone chain of the polymer are novel compositions of matter. Such polymers vary in properties from water-soluble polyelectrolytes useful as thickening agents to thermoplastic elastomers which can be extruded, injection molded, vacuum formed, etc. at elevated temperatures. The elastomeric ionomers are useful as specialty and general purpose rubbers. The ionomers of the instant invention are plasticized with a select group of plasticizers thereby improving the rheological properties of the ionomers.

Abstract: Poly(N-acetyl-α-amino acrylic acid) was prepared by a free radical polymerization reaction. Mild alkaline hydrolysis of the polymer product yielded a second polymer poly(α-amino acrylic acid) (polydehydroalanine). Both polymers exhibited certain polyelectrolyte behavior, although the latter did not behave as expected for an amphoteric polyelectrolyte.

Abstract: Counterion distributing coefficients obtained from isopiestic and electromotive force experiments are presented for solutions of poly(acrylic acid), poly(vinylamine) and poly(ethyleneimine) with and without added salt. The observations lead to the conclusion that a number of factors determining the dependence of the dissociation equilibrium of the functional groups on the degree of ionization, do not affect or scarcely affect the counterion condensation. The very strong counterion binding by the branched poly(ethyleneimine) in comparison with linear polyelectrolytes indicates that the macromolecular structure is of great importance. The values found for the counterion distribution coefficient in salt-free solutions of both linear polyelectrolytes are compared with values calculated from the theories of Lifson-Katchalsky and Manning. The “additivity rules” for polyelectrolyte-salt mixtures as formulated by Lifson-Katchalsky are not obeyed.

Abstract: It has been shown by high-velocity sedimentation that BSA forms soluble complexes with polyacrylic acid (PAA) and sodium polystyrene sulfonate (PSSNa) with neutral water solutions. Factors responsible for polyanion binding of similarly charged BSA molecules are analysed. It has been found that occupation of PAA and PSSNa chains with BSA globules proceeds steadily. BSA-PAA and BSA-PSSNa complexes are compared with the earlier described products of BSA sorption on poly-4-vinyl-N-ethylpyridine bromide, where the occupation of polycations with protein globules proceeds unevenly. Reasons for the existence of two types of soluble BSA-polyelectrolyte complexes are described; probable structural model of BSA complex with polyacids and polyanions is suggested.