Surface energy lowering

The blends, irrespective of the concentration of fluororubber, show surface energy lower than neat rubbers. This is attributed to the migration of silicone mbber to the surface. The presence of silicone rubber on the surface of the blends also contributes to their lower limited oxygen index compared to that of fluoroelastomers. 

Surface contamination can take a number of forms. We are surrounded by a complex mixture of hydrocarbon molecules as a consequence of both our industrial and natural environments. Low surface energy silicones (e.g., vacuum greases and pump oils) are commonly present in the laboratory environment. Silicone contamination is particularly troublesome and is found on many surfaces because few materials have surface energies lower than silicone compounds. 

The water film adsorbed on the surface and neutralizing the charges of surface atoms provides the surface energy lowering of AF. The vapour pressure over the solid phase can be calculated from the adsorption isotherm ... 

It is known simultaneously [104], that the linear expansion A/// is related to the surface energy lowering by the formula ... 

As shown in Table 3.16, the whiskers modified with OTS have lower surface energy, lower polar component, and better hydrophobic and lipophilic properties than untreated whiskers. The dispersive component ratio of potassium titanate whiskers modified with OTS to OTS molecules is much closer to the dispersion value of the -CH2- group rather than the -CH3-group, which indicates that the whisker surface modified with... 

Surface free energy of nitrile-butadiene copol miers, NBR, was found to depend on the mold in which the copolymers were formed. If the mold had low surface free energy, NBR also had lower surface energy, lower adhesion force to the mold, and a lower friction coefficient. It was inferred from this that friction coefficient was an essential parameter for ease of removal of products from molds. ... 

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