J. Phys. IV France 10 (2000) Pr7-321-Pr7-324
Dynamical properties of highly entangled polyalkylmethacrylate solutions : A comparative studyV. Villari, A. Faraone, S. Magazù, G. Maisano and R. Ponterio
Dipartimento di Fisica and INFM, Università di Messina, C.da Papardo, S.ta Sperone 31, 98166 Messina, Italy
The dynamic scattering function of dilute polymer solutions, in the temporal range 10-6÷10-2 is usually dominated by the relaxation of concentration fluctuations. The study of these modes allows to characterize the diffusive properties of the system. By increasing concentration up to the semidilute limit, the entanglement of the polymer chains leads to the appearance of new dynamical processes. We report results of a comparative study on Polyalkylmethacrylates (i.e. Poly(Methyl MethAcrylate (PMMA), Poly(Ethyl MethAcrylate) (PEMA) and Poly(Buthyl MethAcrylate) (PBMA)) in acetone solutions, in the semidilute regime. We will show that, besides a collective diffusive mode, a slow ( 10-1 s) q-independent relaxation is present for PMMA and PEMA.
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