Abstract
In order to understand the nature of polydispersity and characterize the effect of branching architecture, the model blend of linear and star polymer, which is the simplest branched polymer, is contrived. In this blend system, chain dynamics are more strongly affected by the constraint release, due to the different relaxation times of each chain, than by reptation or arm retraction. Material properties of this model linear-star blend deviate from the well-known scaling, []CR ~ M[L]³ and suggest a strong possibility that the scaling of constraint release is lower than the scaling exponent 3. Based on the analogy in dynamics of a pulled chain in entangled melts and star polymer, the linear-star blend model of present work gives a better prediction for linear-star blend than the existing blend model. Due to the simplified scaling for constraint release, the generality of the linear-star blend model of present work is limited only for the high ML and low [Ø]S. Even though such restriction, the linear-star blend model of present work provides the validity of a different approach for the constraint release, []CR ~ML², and a new viewpoint for more realistic linear-star blend model.
Lee, Jung Hun (2000). The viscoelastic properties of linear-star blends. Master's thesis, Texas A&M University. Available electronically from
https : / /hdl .handle .net /1969 .1 /ETD -TAMU -2000 -THESIS -L4403.