Solubility parameter various water-soluble polymers

The intention of this paper is to identify the molecular parameters, which are of particular relevance for the qualitative and quantitative understanding of the flow phenomena caused especially by water soluble polymer additives. The parameters can be classified with respect to primary, secondary, tertiary and quarternary structure. These structure parameters do not only refer to the average molecular weight, molecular weight distribution and co-polymer compositions, but also to the coil dimensions, flexibility and to intermolcular interactions. Some experimental examples will be used to illustrate the applicability of the various methods with special emphasis on high molecular weight water soluble polymers. 

In an inverse emulsion polymerization, a hydrophilic monomer, frequently in aqueous solution, is emulsified in a continuous oil phase using a water-in-oil emulsifier and polymerized using either an oil-soluble or water-soluble initiator the products are viscous latices comprised of submicroscopic, water-swollen, hydrophilic polymer particles colloidally suspended in the continuous oil phase. The average particle sizes of these latices are as small as 0.05 microns. The technique is applicable to a wide variety of hydrophilic monomers and oil media. The inverse emulsion polymerization of sodium p-vinylbenzene sulfonate initiated by both benzoyl peroxide and potassium persulfate was compared to the persulfate-initiated polymerization in aqueous solution. Hypotheses for the mechanism and kinetics of polymerization were developed and used to calculate the various kinetic parameters of this monomer. 

Environmental risk assessment has to address all compartments of the environment like air, water, sediment and soil. The partition of a substance between the various compartments is controlled by the physico-chemical parameters of a substance. Water-soluble or dispersible surfactants and emulsifiers will predominantly affect the water and sediments. As surfactants are widely used not only in manifold industrial applications but also in consumer products the pollution is widely dispersed. The contribution of surfactants used in polymer production is comparably rather small but has nevertheless to be controlled and monitored. 

The value represents the pounds of a chemical that will dissolve in 100 pounds of pure water. Solubility usually increases when the temperature increases. The following terms are used when numerical data are either unavailable or not applicable The term Miscible means that the chemical mixes with water in all proportions. The term Reacts means that the substance reacts chemically with water thus, its solubility has no real meaning. Insoluble usually means that one pound of the chemical does not dissolve entirely in 100 pounds of water. (Weak solutions of Insoluble materials may still be hazardous to humans, fish, and waterfowl, however.) Table 1 provides solubility parameters of polymers and various solvents. 

Polymerisation of vinyl toluene in quaternary microemulsions containing cetyltrimethylammonium bromide as the cationic surfactant was studied using laser Raman spectroscopy and dilatometry. The influences of water soluble (potassium peroxodisulphate, ammonium peroxodisulphate) and oil-soluble (azobisisobutyronitrile, benzoyl peroxide) initiators, monomer, surfactant, cosurfactants (n-alcohol and bifunctional alcohols) and temperature on the rates of polymerisation, energy of activation, particle diameter, number of polymer particles, molecular weight of polyvinyl toluene and number of polymer chains per latex particle were investigated. The dependencies of the kinetic and latex size parameters on the initiators and co-surfactants are discussed in terms of the efficiency of the initiators in initiating the polymerisation and on the interfacial partitioning behaviour of various co-surfactants. 19 refs. 

If the seed latex particles can barely be swollen by the second-stage monomer and a water-soluble initiator is used, then the subsequent seeded emulsion polymerization will be localized near the particle surface layer. Thus, the postformed polymer tends to form a surface layer around the seed latex particle. An example of this kind of morphological structure of latex particles is the seeded emulsion polymerization of methyl methacrylate in the presence of a polyvinylidene chloride seed latex. On the other hand, free radical polymerization can take place inside the seed latex particles. In this manner, various morphological structures of latex particles such as the perfect core/shell, inverted core/shell, dumbbell-shaped, and occluded structures can be achieved, depending on various physical parameters and polymerization conditions. 

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