DescriptionIn this talk the parameter-free tube model of Milner and McLeish for stress relaxation in melts of monodisperse star polymers is extended to star polymers whose arms have a continuous molecular weight distribution, such as the Flory distribution in the case of polycondensate stars. Exact expressions are derived for the relaxation spectrum and the relaxation modulus for star polymers having an arbitrary continuous arm-length distribution. For a Flory distribution a comparison is made with results of dynamic measurements on a melt of 8-arm poly-ε-caprolactone (PCL) stars. An excellent quantitative agreement over a large frequency range is found, however, only if one treats, in contrast with the original parameter-free tube model approach, the entanglement molecular weight that determines the relaxation spectrum as a fitting parameter independent of the entanglement molecular weight of the linear PCL.
|Period||15 Jun 2005|
|Held at||Centre for Analysis, Scientific computing and Applications (CASA), Netherlands|
|Degree of Recognition||National|