Degradation molecular modeling

Eclipsed conformation, 94 molecular model of, 94 Edman, Pehr Victor, 1031 Ed man degradation, 1031-1032 mechanism of. 1032 Eicosanoid, 1067-1070... 

Viscoelastic properties have been discussed in relation to molar mass, concentration, solvent quality and shear rate. Considering the molecular models presented here, it is possible to describe the flow characteristics of dilute and semi-dilute solutions, as well as in simple shear flow, independent of the molar mass, concentration and thermodynamic quality of the solvent. The derivations can be extended to finite shear, i.e. it is possible to evaluate T) as a function of the shear rate. Furthermore it is now possible to approximate the critical conditions (critical shear rate, critical rate of elongation) at which the onset of mechanical degradation occurs. With these findings it is therefore possible to tune the flow features of a polymeric solution so that it exhibits the desired behaviour under the respective deposit conditions. 

Complex 69 was prepared in about 60% yield with about 15% metallation and a small drop in molecular weight (from 73,000 for PMPS to 68,000 for 69), which, allowing for the increase in statistical repeat unit, indicates some degradation. Related model compounds based on the coordination of phenyl rings in phenyltrimethylsilane and 1,2-diphenyltetramethyldisilane were compared with 69. The UV absorption maxima (224 and 337 nm) were almost unchanged from those of the precursor PMPS (223 and 338 nm), which possibly reflects the low metal loading as... 

The experimental data for molecular weight and L/Lo agree well with the hydrolytic degradation predictive model for Estane as shown in Figure 10. Ongoing experimental work validating the Estane hydrolysis model for Estane binder will contribute to providing a robust lifetime prediction for PBX 9501 explosives. 

F6. Francis, C. W., and Harder, V. J., A molecular model of plasmic degradation of crosslinked fibrin. Semin. Thromb. Hemost. 8, 25-35 (1982). 

Derham, M., Edge, M., WTUiams, D. A. R., WTUiamson, D. M. (1992). The Degradation of cellulose triacetate studied hy nuclear resonance spectroscopy and molecular modeling. In Postprints of Polymers in Conservation conference Manchester, 17-19 July 1991 (N.S. AUen, M. Edge and C.V. Horie, eds.) pp. 125-137 Royal Society of Chemistry. 

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