Reaction between Maleic Anhydride and the Isomers of Piperylene

Abstract

Notes 627 excess of water is zero. The Gibbsian surface excess will be proportional to the difference between the area under the concentration curve and the area of the rectangle --0-s. For this case it is easy to see that, even though there is a surface layer of solute (positive adsorption at the interface), the Gibbsian surface excess may be positive, zero or negative depending on the concentrations in the double layer region below the interface. It is also plausible that changes in the bulk concentration will change the concentrations in this region, and thus change the surface excess, even though only slight changes occur in the outer ionic layer. Thus the apparent paradox of a surface deficiency and yet a surface tension less than that of water is readily understandable.

Chemical Analysis of Refinery C5 Hydrocarbon Fractions

“…cis-Piperylene has been shown (21) to react only very slowly with maleic anhydride under the conditions just set forth. The Zrans-isomer reacts rapidly and quantitatively.…”

“…(1600 °F. ), for example (21). Moreover, the piperylenes are removed, in most cases, from trimethylethylene, the closest boiling tertiary mono-olefin, by superfractional distillation, as is pointed out below.…”

The Diels-Alder Diene Synthesis.

“…There appears to be a substantial difference (309) in the rates of addition of maleic anhydride by the cis-and ¿rans-isomers of piperylene. The analysis of a pure mixture of cis-and ¿raras-piperylenes was attempted by Robey and his coworkers, who found that addition ceases between 65 and 78 per cent of completion.…”