Foaming behavior, influencing

Foam behavior and foam stability are strongly dependent on the water hardness. With a water hardness of 0 ppm the foam behavior and foam stability of LAS improves as the molecular mass increases. This behavior is exactly the opposite at a water hardness of 300 ppm. From 100 ppm the optimum for the Cn homologs is obtained. With the same molecular mass, the foam consistancy of the homologs is highest when the content of 2- and 3-phenylalkanes is highest [187]. In terms of stability in hard water a higher 2-phenylalkane content has a positive influence. An increase in molecular mass has the effect of reducing the hard water stability [189-191]. 

Correlation between blend morphology, melt-elongation, and foaming behavior — despite the significant influence only addressed for neat polymers [38], miscible blends [4, 5], and some filled systems [39,40]... 

In the present case, the foam density relates perfectly with the previously observed rheological properties, as a transition in the flow behavior was detected at approximately 20 wt% of PPE (Fig. 13). In the viscoelastic case (below the percolation limit), the PPE content neither significantly influences the foamability nor the blend rheology. At elevated contents (beyond percolation), however, the PPE content strongly affects the rheological response of the blend and, subsequently, degrades the foaming behavior, which is verified by a reduced expandability. 

As previously shown for PPE/SAN blends, the foaming behavior of immiscible blend systems is affected by both the properties of the blend phases and the overall blend structure [1], In the present blend system, the viscosity of one specific blend phase is varied as a result, not only the foaming behavior of the blend phase is altered but also the microstructure of the blend is affected [94]. By investigating blend systems with constant PPE to PS ratios of 75/25 and 50/50, and varying the SAN content in the range of 20-40 wt%, the influence of both the microstructure and the viscosity ratio can be analyzed (Table 3). 

For further understanding the influence of the viscosity ratio on the foaming behavior, an additional blend system with a PPE/PS ratio of 25/75 and a SAN content of 40 w% was investigated. Due to the high PS content, the PPE/PS matrix phase shows a lower viscosity and a similar glass transition temperature when compared to the dispersed SAN phase. As can be seen in Fig. 29a, the decrease in viscosity of the PPE/PS clearly promotes the formation of elevated SAN phase in comparison to the previously shown blends. 

Gutmann P, Ruckdaschel H, Bangarusampath DS, Altstadt V, Schmalz H, Muller AHE (2009) Influence of the microstructure on the foaming behavior of an immiscible blend system. Antec... 

Dussaud, A., RobiUard, B., Carles, B., Duteurtre, B., Vignesadler, M. (1994). Exogenous lipids and ethanol influences on the foam behavior of sparkling base wines. J. Food Sci., 59, 148. 

The compression behavior of PP foams is influenced by the cellular stmcture and by the mechanical properties of the PP matrix polymer. Figure 2(a) shows the compressive stress-strain curve of a PP foam schematically. The au-ve displays linear elastic behavior at low strains followed by a long collapse plateau, tmncated by a regime of densifica-tion in which the stress rises steeply [1, 3]. 

As we will show in Chapter 4, the entry and spreading behavior of antifoam oils is central to their mode of action. In particular, such oils must enter the air-foaming liquid surface if they are to function. It has been shown that it is not necessary that they spread over that surface [15]. However, it has also been shown [34-36] that the presence of spread films over the air-foaming surface influences the stability of the relevant pseudoemulsion films, the emergence into that surface, and therefore the effectiveness of an antifoam. The relevance of the entry and spreading behavior of oils to antifoam action therefore justifies the detailed review given here. 

Zhai, W. T., H. Y. Wang, J. Yu, J. Y. Dong, and J. S. He. 2008b. Foaming behavior of isotactic polypropylene in supercritical COj influenced by phase morphology via chain grafting. Pofymer 49 3146-56. 

Various geometric coring patterns ki polyurethanes (171,175) and ki latex foam mbber (176) exert significant influences on thek compressive behavior. A good discussion of the effect of cell size and shape on the properties of flexible foams is contained ki References 60 and 156. The effect of open-ceU content is demonstrated ki polyethylene foam (173). 

The chemical composition, physical stmcture, and key physical properties of a foam, namely its stabiHty and theology, are all closely interrelated. Since there is a large interfacial area of contact between Hquid and vapor inside a foam, the physical chemistry of Hquid—vapor interfaces and their modification by surface-active molecules plays a primary role underlying these interrelationships. Thus the behavior of individual surface-active molecules in solution and near a vapor interface and their influence on interfacial forces is considered here first. 

The influence of stable adhesion between binder and filler on the water absorption of a syntactic foam is corroborated by the thermomechanical behavior of the foam. 

Influence of compatibilization on the foam morphology - despite the significant influence and relevance of compatibilization on the blend structure and interfacial behavior, only partly discussed for polyolefins/styrenics blends [37]... 

Several factors can be identified as being crucial for the foaming of immiscible polymer blends the blend morphology, the phase size of the blend constituents, the interfacial properties between the blend partners, and, last but not least, the properties of the respective blend phases such as the melt-rheological behavior, the glass transition temperature, the gas solubility, as well as the gas diffusion coefficient. Most of these factors also individually influence the melt-rheological behavior of two-phase blends. 

The gas/liquid and liquid/liquid systems are relevant to biomedical and engineering applications. The large interfacial area in foams, macro- and microemulsions is suitable for rapid mass transfer from gas to liquid or liquid to gas in foams and from one liquid to another or vice versa in macro- and microemulsions. The formation and stability of these systems may be influenced by the chain length compatibility which may also influence the flow through porous media behavior of these systems. Therefore, the present communication deals with the effect of chain length compatibility on the properties of monolayers, foams, macro- and microemulsions. An attempt is made to correlate the chain length compatibility effects with surface properties of mixed surfactants and their flow behavior in porous media in relation to enhanced oil recovery. 

The spectrum of surface active behavior displayed by food proteins directly reflects differences in structural and physicochemical properties among the proteins originating from various sources i.e. meat, milk, legumes. Chemical or enzymatic modification of model food proteins has indicated that alteration of specific structural features e.g. net charge, disulfide bonding, size, does influence film formation, foaming and emulsifying properties. 

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