Methylene chain defects

Solid hydrocarbon soils can be rapidly removed from the surface of a ZnSe IRE by alkyl polyethylene oxide) surfactants. The removal mechanism involves penetration of a small amount of the surfactant into the hydrocarbon layer, which causes an increase in methylene chain defects in the soil, and displacement of solid soil from the substrate. Solubilization of a large fraction of the solid soil is not required. 

Considerable experimental evidence (1-6,11) suggests that the methylene chains inside of a spherical micelle are almost as disordered as in the bulk liquid state (i.e. they contain a significant proportion of gauche conformers). The FTTR spectra of micellar SDS support this assertion, exhibiting CH2 stretching and scissoring band frequencies which are comparable to those found in the spectra of liquid hydrocarbons (1-6,11). A recent quantitative analysis of the CH2 defect modes of SDS has shown that the disorder of me methylene tails is similar to that found in liquid tridecane (11). 

It is well-known that the occurrence of chain defects, in the form of for example small methylene sidegroups, could reduce this Tm-value [4J. This offered the possibility to reduce the relative high processing temperature of PK copolymers. The effect of addition of small amounts of propylene to the carbon monoxide/ ethylene mixture on the Tm-value is shown in Figure 9.1. A nearly linear decrease of the Tm-value as a function of the weight percentage of C3 was found for propylene concentrations between 0 and about 15 %wt. i.e. for the Tm-value holds ... 

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