Polymacromonomers: Dynamics of dilute and nondilute solutions
HÉROGUEZ, Valérie
Laboratoire de Chimie des polymères organiques [LCPO]
Team 1 LCPO : Polymerization Catalyses & Engineering
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Laboratoire de Chimie des polymères organiques [LCPO]
Team 1 LCPO : Polymerization Catalyses & Engineering
HÉROGUEZ, Valérie
Laboratoire de Chimie des polymères organiques [LCPO]
Team 1 LCPO : Polymerization Catalyses & Engineering
< Réduire
Laboratoire de Chimie des polymères organiques [LCPO]
Team 1 LCPO : Polymerization Catalyses & Engineering
Langue
en
Article de revue
Ce document a été publié dans
International Journal of Biological Macromolecules. 2005, vol. 38, n° 6, p. 2400-2409
Elsevier
Résumé en anglais
Polymacromonomers (PMs) are a class of branched polymers whose global shape depends strongly on the degree of polymerization of the backbone and the length of the side chain. As opposed to their equivalent linear chains, ...Lire la suite >
Polymacromonomers (PMs) are a class of branched polymers whose global shape depends strongly on the degree of polymerization of the backbone and the length of the side chain. As opposed to their equivalent linear chains, PMs can indeed adopt spherical, cylindrical, or wormlike shapes. Other parameters such as the rigidity of the side chain, the distance between branches and the interactions (incompatibility) between the backbone and the branches can also contribute to the global morphology of the PMs. In this work we describe the dynamical behavior of several poly(omega-norbornenyl polystyrene) differing by their backbone and their side chain lengths, in dilute and nondilute ranges of concentration, using dynamic light scattering and viscosity experiments. The results obtained, using both techniques, suggest dense and nonentangled particles as revealed by the low viscosity values and the scaling laws observed for the variation of the diffusion coefficient as a function of the molar mass and the concentration c. The transition from dilute to nondilute regime is characterized by an abrupt increase of the diffusion coefficient with the concentration, as opposed to the case of linear and flexible polymer coils. Above this concentration, the diffusion coefficient is independent of the molar mass and hardly varies with the concentration. It is identified as reflecting the overall collective motion of the branches. This transition is also observed in the variation of the reduced viscosity eta(sp)/c as a function of c. Similar studies have been carried out on star polymers of roughly same molar mass where no such an abrupt transition was observed.< Réduire
Mots clés en anglais
MACROMOLECULES
POLY(MACROMONOMER)S
LENGTH
CYCLOHEXANE
POLYMERS
OPENING METATHESIS POLYMERIZATION
LIGHT-SCATTERING
CYLINDRICAL BRUSHES
POLYSTYRENE MACROMONOMERS
INTEGRAL-EQUATIONS
Origine
Importé de halUnités de recherche