Foaming chemical structure

Typically, large-scale gas filling makes the main characteristics of foam plastics — coefficients of heat and temperature conductivity, dielectric permeability, and the tangent of the dielectric loss angle — totally independent of the chemical structure of the original polymer [1],... 

Examinations of the connection between the chemical structure of alkylaryl sulfates and their physical-chemical properties show that solubility, aggregations and adsorption behavior, foam behavior and consistency are determined by the following structural elements the length of the alkyl chain, the position at which the benzene ring is connected to the alkyl chain, and the substitution pattern of the benzene ring [187,188]. 

Despite having a greater average carbon number than AOS 1618, IOS 1720 exhibits a lower foam half-life, 9.4 min as compared with 26.6 min (Table 23). The most probable cause of this behavior is the lower linearity of IOS 1720 its parent olefin was 22% branched, vs. <4% for the parent olefin of AOS 1618 with all other chemical structure features being the same. 

Q-1 represents the reciprocal value of the well known gas throughput number Q. Fr is the Froude number, here formed with the gas throughput and cT is the dimensionless concentration (in ppm) of the foaming agent in the liquid. S are the physical properties which affect foam stability. Because they are neither known by number (i) nor by kind, instead of S the type of the foaming agent (name and chemical structure) must be given. 

Effects of Surfactant Chemical Structure on One-Atmosphere Foaming Properties... 

Surfactant foaming properties are related to surfactant chemical structure parameters such as hydrophobe size, ethylene oxide chain length, and hydrophile functional group. 

Increasing the test pressure from one atmosphere to 2500 psig COj did not alter the effect of surfactant chemical structure on relative foaming performance. 

Correlation equations relating surfactant chemical structure to performance characteristics and physical properties have been established. One atmosphere foaming properties of alcohol ethoxyl-ates and alcohol ethoxylate derivatives have been related to surfactant hydrophobe carbon chain length, ethylene oxide content, aqueous phase salinity, and temperature. Similar correlations have been established for critical micelle concentration, surfactant cloud point, and surfactant adsorption. 

Foam exhibits higher apparent viscosity and lower mobility within permeable media than do its separate constituents.(1-3) This lower mobility can be attained by the presence of less than 0.1% surfactant in the aqueous fluid being injected.(4) The foaming properties of surfactants and other properties relevant to surfactant performance in enhanced oil recovery (EOR) processes are dependent upon surfactant chemical structure. Alcohol ethoxylates and alcohol ethoxylate derivatives were chosen to study techniques of relating surfactant performance parameters to chemical structure. These classes of surfactants have been evaluated as mobility control agents in laboratory studies (see references 5 and 6 and references therein). One member of this class of surfactants has been used in three field trials.(7-9) These particular surfactants have well defined structures and chemical structure variables can be assigned numerical values. Commercial products can be manufactured in relatively high purity. 

Foaming properties can be quantitatively related to surfactant chemical structure, surfactant physical properties, and test conditions using the technique of multiple correlation analysis.(11) The current studies were restricted to linear correlation equations to permit the analyses to be performed on a small microcomputer. While non-linear equations having higher correlation coefficients than obtained herein can be developed, theoretical insights are often limited due to the complexity of the various terms of such equations. The quality of the correlations were assessed using the correlation coefficient (r ) criteria of Jaffe (12)... 

Surfactant critical micelle concentration (cmc) may be related to chemical structure using multiple correlation analysis. The cmc value plays an important role in surfactant adsorption, foaming, and interfacial tension properties. The 25 C cmc values of a series of high purity single component highly linear primary alcohol ethoxylates (Table 6) were analyzed using equation 4 ... 

Both the use of one atmosphere foaming experiments and the technique of multiple correlation analysis have a common purpose minimizing the effort required to develop new surfactants for mobility control and other EOR applications. Proper use of these techniques with due consideration of their limitations can substantially reduce the number of experiments required to develop new surfactants or to understand the effect of surfactant chemical structure on physical properties and performance parameters. ... 

The limitation of the use of one atmosphere foaming experiments to rank order the predicted surfactant performance in permeable media rather than in quantitatively or semi-quantitatively predicting the actual performance of the surfactants under realistic use conditions has already been mentioned. Multiple correlation analysis has its greatest value to predicting the rank order of surfactant performance or the relative value of a physical property parameter. Correlation coefficients less than 0.99 generally do not allow the quantitative prediction of the value of a performance parameter for a surfactant yet to be evaluated or even synthesized. Despite these limitations, multiple correlation analysis can be valuable, increasing the understanding of the effect of chemical structure variables on surfactant physical property and performance parameters. 

Foaming properties of alcohol ethoxylates and alcohol ethoxylate derivatives are related to chemical structure features such as hydrophobe size and linearity, ethylene oxide chain length, and the terminating group at the end of the ethylene oxide chain. Foaming properties may be mathematically related to chemical structure parameters using multiple correlation analysis. ... 

Construction-material studies on the influence of the chemical structure and qjecific features of the macro- and microstructure on the phyacomechanical properties of foamed polymers, etc. 

Physical studies of molecular mechanisms, physical and chemical phenomena and elucidation of changes in foam properties under the effect of external factors Studies on the chemical structure and morphology using methods of ectroscopy. X-ray analysis, microscopy, thermography, etc. 

New polyols, such as polycarbonate polyols (Duracatb, PPG Ind. Inc.), hydantoin-containing polyols (Dantocol DHE, Lonza Inc.), polyo-lefinic polyols (Poly bd, Atochem Co.) and its hydrogenated polyols, i.e.. Polytail (Mitsubishi Chemical Corp.) are now available as conunercial products. An application of polyolefinic polyols for foams has recently been reported (119). The chemical structures of the above polyols are shown below ... 

As opposed to flexible urethane foams, rigid urethane foams have a highly cross-linked chemical structure and a high percent of closed cells, e.g., over 90%. Rigid urethane foams can be classified as follows unmodified (or pure) rigid urethane foams and modified rigid urethane foams, which include isocyanurate-modified, epoxy-modified, amide-modified and oxazolidone-modified rigid urethane foams. 

Frisch, K.C., "Relationship of Chemical Structure and Properties of Rigid Urethane Foams," Journal of Cellular Plastics, 1(2) 325-330 (April 1965). 

Additives and Fillers for Structural Foam Chemical Blowing Agents Processing Structural Foam Tooling... 

CFCs (chlorofluorocarbons) - As applied to polyurethane foams, blowing agents having chlorine and fluorine in their chemical structure. CFCs are gradually being replaced by other blowing agents because of concern about their adverse effect on the atmospheric ozone layer. 

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