Dielectric properties of segmented polyurethanes for electromechanical applications

cited By 10International audienceThe paper deals with electromechanical and dielectric properties of polyurethanes (PU) block-copolymers. Most of the works published in the literature only consider electrostriction at room temperature at a given frequency. In this work, it is shown that electrostrictive coefficient ME is divided by 3-10 at increasing frequency over 3 decades of frequency, depending on the ratio of hard to soft segments in PU. Thus it is important to analyze the energy conversion efficiency by investigating the dielectric and viscoelastic properties. This work deals with the study of dielectric properties of 3 PU with different fractions of hard segments. Three relaxation phenomena (β, α and conduction) were investigated for each PU in the temperature-frequency range studied here, in order to optimize the copolymer composition in view of their best efficiency as actuators or mechanical energy harvesting devices

Temperature dependence of the molecular dynamics in amorphous polymers through the rubber-glass transition

International audienc

Secondary dielectric relaxations in dried amorphous cellulose and dextran

International audienc

Thermally stimulated creep: a theoretical understanding of the compensation law

International audienc

Clustering and percolation effect in microcrystalline starch reinforced thermoplastic

International audienc

Thermosplastic nanocomposites filled with wheat straw cellulose whiskers. Part II: effect of processing and modeling

International audienc

New nanocomposite materials: microcrystalline starch reinforced thermoplastic

International audienc