Water-soluble polymers with dilute

Interaction of Water-Soluble Polymers with Dilute Lamellar Surfactants... 

Therefore, methods of stabilizing dispersions against water injection (e.g., use of other surfactants, lamellar liquid crystals, use of very dilute solutions of water-soluble polymers with surfactants) might aid commercialization by reducing surfactant costs. 

In a novel process, FIPI was also applied to the emulsiflcation of polymer melts in water, thus providing an alternative method to emulsion polymerization for the production of latexes. " " In fact, some thermoplastic melts (such as polyethylene) cannot be obtained through the emulsion polymerization route hence, the present technique is an example of PI providing a novel product form. To achieve the emulsiflcation of thermoplastics, it is necessary to operate near or above 100°C and at elevated pressures, which necessitates the use of polymer processing equipment fitted with a MFCS mixer at the outlet. It was found that molecular surfactants could not be used to obtain the initial (water-in-polymer melt) emulsion. Instead, hydrophobically modified water-soluble polymers were used as the surface active material. After the phase inversion in the MFCS mixer, the resulting emulsion was diluted to the level required. This also freezes the molten latexes. The important attributes of FIPI emulsification include a low level of surfactant use, low temperature processing, production of submicrometer particles with a narrow size distribution, and production of novel products. 

Dilute solution properties in water are very important for water-soluble polymers [27], not only in their characterization but also in determining their performance under actual use conditions. These polymers include the acrylamide polymers, namely polyacrylamide and its structural variants, whose range of applications encompasses their use as soil modifiers. The results of calculations [28] of the specific refractive index increments of random copolymers of acrylamide with N-benzyl methacrylamide and with N-methyl methacrylamide are shown in Figure 8.3. (See Section 17.E for the method used to calculate the properties of random copolymers.) The details of the calculations (not shown) indicate that (a) the specific volumes of the homopolymers are in the order polyacrylamide < poly(N-benzyl methacrylamide) < poly(N-methyl methacrylamide), and (b) the refractive indices are in the order polyacrylamide poly(N-methyl methacrylamide) poly(N-benzyl methacrylamide). The results shown for the copolymers in Figure 8.3 arise from the multiplicative combination of these trends. 

In order to emphasize the role of the inter facial films and to highlight the most recent viewpoints on the stability of microemulsions, sponge phases, and dilute lamellar phases, some of the experimental facts about phase behavior of microemulsion systems containing alcohol are reviewed in this chapter. The systems investigated consist of water, oil, alcohol, and sodium dodecylsulfate (SDS). In the next section, the theoretical aspects of the stability of surfactant phases are briefly discussed. Then in Secs. Ill and IV the effects of varying alcohol and oil chain lengths and the addition of a water-soluble polymer are examined. The examination of multiphase regions provides the location of lines of critical points or critical endpoints. This chapter also deals with the study of several physical properties in the vicinity of critical points. 

Self-doped PABA has been prepared in water in the presence of excess fructose, and one equivalent of fluoride to monomer, under ambient conditions (for details see Chapter 3, Section 3.2.2) [37]. The resulting water-soluble polymer was precipitated by dilution in pure water. Following filtration and rinsing with water, the precipitate was washed with 0.5 M F3C1 to remove D-fructose, and dried in air. Pellets of air-dried PABA were produced at 10 000 psi for 5 min and crosslinked at 100 °C under vacuum for 24 h. The atomic percent of boron and fluorine in a heat treated pellet as determined by X-ray photoelectron spectroscopy... 

High molecular-weight polypeptides were synthesized by the standard N-carboxy-o-amino acid anhydride (NCA) method. The u-carbobenzoxy groups of the polypeptide in dioxane solution were removed with hydrogen bromide gas. The water-soluble polymers were then dialyzed repeatedly against dilute HCl and finally water. The concentrations of the polypeptides were determined by microKjeldahl analyses. All CD spectra were measured on a Jasco J-10 or, more recently, J-500A spectropolarimeter (for its calibration, see Ref. 8). 

For most polymers soluble in organic (nonpolar) solvents, the solubility increases upon heating. For water-soluble polymers, the situation is more delicate the solubility may either increase or decrease as a function of temperature. The solubility limit is often called upper (or lower) critical solubility temperature (UCST or LOST, respectively). For many water-soluble polymers, the LOST is relatively low (from 27-28 C for poly(N-isopropylacry-lamide) (PNIPAM) to about 100 °C for poly(ethylene oxide) (PEO)) and can be reached at normal atmospheric pressure such polymers are often referred to as thermosensitive. In terms of Flory theory of polymer solutions, the UCST or the LCST can be associated with the 6 temperature. Below UCST (above LCST), the polymer solution undergoes macroscopic phase separation into homogenous polymer-rich phase (precipitate) and dilute... 

A majority of commercial applications of aqueous developable ceramic compositions use acid-containing polymer binders and dilute aqueous base as a development solution. However, a totally aqueous development system can be formulated with the use of water-soluble polymer binders [22]. Ogawa proposes the use of nonionic water-soluble polymers, such as the cellulose ethers methyl cellulose, hydroxy methyl cellulose, hydroxy ethyl cellulose, and hydroxy propyl cellulose, as the polymeric binder. Molecular weights in the range of 30,000 to 1,(X)0,(X)0 are preferred in these compositions. When... 

Smith, G. L. and C. L. McCormick (2001). Water-soluble polymers. 79. Interaction of microblocky twin-tailed acrylamido terpolymers with anionic, cationic, and nonionic surfactants. Langmuir 17(5) 1719—1725. Sreenivasan, K. R. and C. M. White (2000). The onset of drag reduetion by dilute polymer additives, and the maximum drag reduction asymptote. Journal of Fluid Mechanics 409 149—164. 

The chemistry of the production of polyamide resin is very similar to the original process by which nylon was produced. In the Nylon 66 process a dicarboxylic acid, such as adipic acid is reacted with a six carbon amine, for example hexamethylene-diamine, to produce a synthetic fiber In the case of polyamide resin, a dicarboxylic add is reacted or condensed with an amine such as diethylenetriamine to form an amino polyamide. The secondary amine groups of this water soluble polymer are then reacted with epichlorohydrin to form the aminopolyamide epichlorohydrin intermediate. This is then crosslinked to build molecular weight whilst maintaining solubility. The polymerization reaction is terminated by dilution and acidification. 

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