Formulation foams

The urethane forming ingredients in a polyurethane foam formulation are the isocyanate (1) and the polyol (2) as shown in equation 3. 

Fillers (qv) are occasionally used in flexible slab foams the two most commonly used are calcium carbonate (whiting) and barium sulfate (barytes). Their use level may range up to 150 parts per 100 parts of polyol. Various other ingredients may also be used to modify a flexible foam formulation. Cross-linkers, chain extenders, ignition modifiers, auxiHary blowing agents, etc, are all used to some extent depending on the final product characteristics desired. 

Modification of cellular polymers by incorporating amide, imide, oxa2ohdinone, or carbodiimide groups has been attempted but only the urethane-modified isocyanurate foams are produced in the 1990s. PUIR foams often do not require added fire retardants to meet most regulatory requirements (34). A typical PUIR foam formulation is shown in Table 6. 

The polyurethane industry is dominated by the multinational isocyanate producers. Several of the principal isocyanate producers, including BASF, Bayer, Dow, ICI, and Olin, also manufacture polyols, the other significant building block for polyurethanes. Annual production capacities of the global aromatic isocyanate producers are Hsted in Table 11. Polyols, mainly used for flexible foam production, account for 65 wt % in a flexible foam formulation, 35% in rigid polyurethane foams, and even less in PUIR foams. 

The second largest component of a foam formulation is the isocyanate. 80 20 TDI is found to be the most suitable of the various isocyanates available and was, for many years, used almost exclusively. 

Surface active agents are important components of foam formulations. They decrease the surface tension of the system and facilitate the dispersion of water in the hydrophobic resin. In addition they can aid nucleation, stabilise the foam and control cell structure. A wide range of such agents, both ionic and non-ionic, has been used at various times but the success of the one-shot process has been due in no small measure to the development of the water-soluble polyether siloxanes. These are either block or graft copolymers of a polydimethylsiloxane with a polyalkylene oxide (the latter usually an ethylene oxide-propylene oxide copolymer). Since these materials are susceptible to hydrolysis they should be used within a few days of mixing with water. 

PUR are a broad class of highly cross-linked plastics prepared by multiple additions of poly-functional hydroxyl or amino compounds. Typical reactants are polyisocyanates [toluene diisocyanate (TDI)] and polyhydroxyl molecules such as polyols, glycols, polyesters, and polyethers. The cyanate group can also combine with water this reaction is the basis for hardening of the one-part foam formulations. 

Earlier Kern River pilot results [59,82,83] showed that a steam foam formulation based on AOS containing 16-18 carbon atoms in the hydrophobe improves sweep efficiency and oil recovery of the steam drive but propagates relatively slowly and leaves the same residual oil saturation (ROS) as steam. 

Hydrosilation reactions have been one of the earlier techniques utilized in the preparation of siloxane containing block copolymers 22,23). A major application of this method has been in the synthesis of polysiloxane-poly(alkylene oxide) block copolymers 23), which find extensive applications as emulsifiers and stabilizers, especially in the urethane foam formulations 23-43). These types of reactions are conducted between silane (Si H) terminated siloxane oligomers and olefinically terminated poly-(alkylene oxide) oligomers. Consequently the resulting system contains (Si—C) linkages between different segments. Earlier developments in the field have been reviewed 22, 23,43> Recently hydrosilation reactions have been used effectively by Ringsdorf 255) and Finkelmann 256) for the synthesis of various novel thermoplastic liquid crystalline copolymers where siloxanes have been utilized as flexible spacers. Introduction of flexible siloxanes also improved the processibility of these materials. 

While drilling low-pressure reservoirs with nonconventional methods, it is conunon to use low-density dispersed systems, such as foam, to achieve underbalanced conditions. To choose an adequate foam formulation, not only the reservoir characteristics but also the foam properties need to be taken into account. Parameters such as stability of foam and interactions between rock-fluid and drilling fluid-formation fluid are among the properties to evaluate while designing the drilling fluid [13]. 

A second new dispensable rigid polyurethane foam formulation was acquired that did not contain the phosphate adducts. Critical design requirements were the same as In the first formulation. The respec-... 

Two different dispensable rigid polyurethane foam formulations were found inadequate... 

THE USE OF POLYFUNCTIONAL MONOMERS IN COMPRESSION-MOULDED LOW-DENSITY POLYETHYLENE FOAM FORMULATIONS... 

A stndy was made of the effects of foam formulation and process conditions and liner composition on the adhesion of HCFC-141b blown rigid PU foam thermal insulation to refrigerator liner protective layers made of ABS, high-impact PS (HIPS), PE and blends of HIPS and PE containing a compatibiliser and adhesion promoter. A tensile test was used to quantify the level of adhesion before and after thermal cycling, and the Brett mould was used for laboratory simulations of foam adhesion within... 

Foam hardness is an important property of flexible foams because foam producers typically segregate grades of foam on the basis of the combination of foam hardness and density [163]. Foam formulations that can increase foam hardness without increasing density, or without the addition of hardening additives... 

Materials. The flexible polyurethane (polyether) foam, formulated from a polyol, tolylene diisocyanate, emulsifier, catalyst, and blowing agent, was obtained from the Nopco Chemical Co. It had a density of about 1.5 pounds per cubic foot (0.02 gram per cc.) and contained approximately 40 open cells per linear inch. The foam samples were washed in detergent, dried, and weighed before being irradiated. 

A reticulated foam is the end result of a manufacturing technique as opposed to a chemistry. In the next chapter, we will introduce readers to the reactions and components that yield this class of polymer. It is important to note that most, if not all, of the foam formulations we will discuss can be converted into reticulated foams to take advantage of the properties of their unique structures. 

Domingo et al. evaluated immobilization of trichloroethylene-degrading Burkholderia cepacia bacteria using hydrophilic polyurethane foam. The influences of several foam formulation parameters upon cell retention were examined. Surfactant type was a major determinant of retention a lecithin-based compound retained more cells than Pluronic- or silicone-based surfactants. 

Messy semisolid foam formulations make administration difficult... 

Phenolic foam formulations consisted of the following components, in parts by weight resol, 100 sulfuric acid (49%), 10 phosphoric acid, 12.5 l,l,2-trichloro-l,2,2-trifluoromethane (R113, blowing agent), 5 polyoxyethylene sorbitan monostearate (surfactant), 0.6. 

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