74 research outputs found
Mediating gel formation from structurally controlled poly(electrolytes) through multiple "head-to-body" electrostatic interactions
Tuning the chain-end functionality of a short-chain cationic homopolymer,
owing to the nature of the initiator used in the ATRP polymerisation step, can
be used to mediate the formation of a gel of this poly(electrolyte) in water.
While a neutral end group gives a solution of low viscosity, a highly
homogeneous gel is obtained with a phosphonate anionic moiety, as characterized
by rheometry and diffusion NMR. This novel type of supramolecular control over
poly(electrolytic) gel formation could find potential use in a variety of
applications in the field of electroactive materials
Dispersion and Localization of Nanoparticles in Polymers : A Rheological Approach
International audienc
Dispersion and Localization of Nanoparticles in Polymers: A Rheological Approach
International audienc
Dispersion and Localization of Nanoparticles in Polymers : A Rheological Approach
International audienc
Propriétés viscoélastiques de polymères linéaires à très large distribution de masses molaires
A modified tube dilatation theory for the relaxation of entangled linear polymer melts
Abstract: In this paper, the "tube dilatation" or "tube Enlargement" concept introduced by Marrucci, is revisited in the case of broad entangled linear polymer melts. Using the tube fluctuation relaxation function of Doi and a linear mixing rule, the model implicitly contains both the features of double reptation and time modification by tube renewal. It has been shown that theoretical arguments of both double reptation with tube renewal and tube dilatation can be used to take into account the effect of polydispersity on the distribution of relaxation times. The model has been tested for some polymers with various N/Ne values. However, experiments indicate that the loss of only one entanglement does not systematically induce a change of the relaxation times through a constraint release and tube renewal process. The freeing of a critical volume, larger than the volume of a tube segment, is required to induce an efficient dilution effect on relaxation times
Une modification du modèle de Leonov expliquant les plateaux secondaires sur le module de perte par un mécanisme de réorganisation interne aux agglomérats dans les polymères chargés
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