Study on the Entanglement Effect between Topologically Different Polymer Chains

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To understand the nature of entanglement governing physical properties of condensed polymer systems, we examined the relaxation behavior of 1) binary blends of monodisperse polystyrenes of different molecular weight, 2) styrene-butadiene block polymer micelles dispersed in polybutadiene matrix, 3) blends of linear/4-arm star polystyrenes, and 4) natural rubber networks with entrapped cis-polyisoprene, employing viscoelastic and dielectric spectroscopy. Utilizing one of the components such as, for example, 1) the high molecular weight component. 3) the star-chains, and 4) the entrapped free chains as a probe, we determined the relaxation time and its distribution of the probes as a function of molecular weight and composition of the systems.Realizable relaxation modes are determined by relative length of the characteristic times of the probes and matrix chains confining the probes. Thus, we could separately evaluate the elementary relaxation processes of the probes: In terms of the "tube" theory, they are repatation, tube renewal, and path breathing modes. In usual bulk polymer systems, these modes take place si-multeneously in a competitice manner and thus unseparable. However, by the present methods utilizing a probe component, we could separately evaluate and interprete in molecular terms the relaxation processes involved in the systems. Thus, we could clarify the features of the effect of entanglement on the dynamics of flexible polymer chains in the condensed systems. In industrial application, these knowledges will provide important clues to design processing conditions and properties of end-products such as high-impact plastics.