Polymer-enhanced foams

Sydansk, R.D., Polymer-Enhanced Foam Laboratory Development and Evaluation in Proc., International Symposium on Oilfield Chemistry, Society of Petroleum Engineers Richardson, TX, 1993, SPE paper 25168. 

U.S. 4,576,744 (1986) Edwards et al. (Lever Brothers) Polymers Enhanced foam stability and increased viscosity... 

Huh, C. and Rossen, WJl. 2008. Approximate Pore-Level Modeling for Apparent Viscosity of Polymer-Enhanced Foam in Porous Media. SPE J. 13 (1) 17-25. SPE-99653-PA. doi 10.2118/99653-PA. 

Sydansk, R.D. 1994a. Polymer-Enhanced Foams Part 1 Laboratory Development and Evaluation. SPE Advanced Technology Series 2 (2) 150-159. SPE-25168-PA. doi 10.2118/25168-PA. 

Several recent patents describe the benefits of polymers in LDLDs (Table 7.15). Polymers are well known to interact with surfactants and provide many interesting properties. Some of the benefits claimed in the patents summarized in Table 7.15 are soil resistance due to amino acid copolymers, polyethylene glycol as a grease release agent, increased grease removal from polyoxyethylene diamine, enhanced foam volume and duration, increased solubility, and enhanced mildness by ethylene oxide-propylene oxide copolymers. As described in these various patents, the addition of polymers to LDLDs can aid performance in many important attributes of the product. 

In drilling fluid applications, several types of viscosity modifiers can be used to enhance foam stablity. These include partially hydrolyzed polyacrylamide (PHPA) clays, such as bentonite xanthan gum guar gums starches cellulosic polymers, such as hydroxy ethyl cellulose (HEG) and sodium carboxy methyl cellulose (SCMC). In Table 8, base fluid viscosities and drainage times for one-half and four-fifths of the base fluids are recorded in a foam system consisting of an anionic foamer, sodium lauryl sulfate (SLS) and a nonionic foamer, TXlOO - ethoxylated octyl phenol. It can be seen that in these systems base fluid viscosity alone... 

Few examples of nanocomposites in which the cellulosic nanostructure is used in biobased thermosets can be also foimd. Due to the fact that these environment friendly composites suffer from several limitations, such as low mechanical properties due to low strength in reinforcement plus inadequate interfacial strength, and that cellulose nanostructures have been shown to have significant potential as a reinforcement, the possibility of using cellulose nanofibers as reinforcements in a bio-derived resin was revised. In Masoodi et al. [200], cellulose nanofibers were used as reinforcements in the forms of layered films, while in Lee et al. [201] the stability of the gas-soybean oil foam templates and the mechanical properties of the polymer nanocomposite foams are enhanced upon the addition of bacterial cellulose nanofibrils. Other examples of biobased thermosets containing cellulosic nanoreinforcements are the work of Shibata [202] in which the use of a biobased epoxy was revised, and systems in which cellulose nanocrystals are incorporated in biobased polyurethanes [203,204], Few examples exist also in the literature on the polymerization of furfuryl alcohol in presence of CNR [205,206] in these papers, the authors established the feasibility of producing furfuryl... 

Shampoos. These are normally a gelled surfactant solution of well-defined associated structures, e.g. rod-shaped micelles. The latter are produced by addition of electrolyte to a surfactant solution. A thickener such as a polysaccharide may be added to increase the relaxation time of the system. In addition, some surfactants such as amine oxides are added to enhance foaming of the shampoo on application. The interaction between the surfactants and polymers at the interface is of great importance in arriving at the right formulation. 

It is believed that, similar to inorganic filler-enhanced nucleation, the shear/ extensional flow in different regions of the die, as well as the expansion of nucleated bubbles near the nanoparticles, would generate a pressure fluctuation around the suspended nanoparticles. The schematic in Figure 3.4 illustrates the induced-extensional flow around the side surface of the nanoclay particle. In extreme situations, such a local pressure held may even be negative and significantly promote cell nucleation. More details about the cell nucleation mechanism of polymer/fillers foaming systems have been presented in our newly submitted journal paper (Zhai et al., 2012), and the readers may get more information from this review paper. 

A literature survey on polymer nanocomposite foam lays emphasis on the fact that nanofillers play a vital role in the enhancement of the mechanical properties of foams because they enhance the matrix and modify the foam structure. While huge progress has been made with respect to the understanding of the mechanical properties of polymer foams, more work is needed to fully reveal the relationships between various mechanical properties and foam structure, so that the properties of foams can be optimized. 

The focus of more recent work has been the use of relatively low concentrations of additives in other oil recovery processes. Of particular interest is the use of surfactants (qv) as CO2 (4) and steam mobiUty control agents (foam). Combinations of older EOR processes such as surfactant-enhanced alkaline flooding and alkaline—surfactant—polymer flooding show promise of improved cost effectiveness. 

About half of the styrene produced is polymerized to polystyrene, an easily molded, low-cost thermoplastic that is somewhat brittle. Foamed polystyrene can be made by polymerizing it in the presence of low-boiling hydrocarbons, which cause bubbles of gas in the solid polymer after which it migrates out and evaporates. Modification and property enhancement of polystyrene-based plastics can be readily accomplished by copolymerization with other substituted ethylenes (vinyl monomers) for example, copolymerization with butadiene produces a widely used synthetic rubber. 

Choose macromolecular compounds like water-soluble polymers and proteins over surfactants and electrolytes as foam stabilizers for products with enhanced skin feel and skin mildness. 

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