58 research outputs found
Kinetics of the glass transition of styrene-butadiene-rubber : Dielectric spectroscopy and fast differential scanning calorimetry
The glass transition is relevant for performance definition in rubber products. For extrapolation to high-frequency behavior, time–temperature superposition is usually assumed, although most complex rubber compounds might be outside of its area of validity. Fast differential scanning calorimetry (FDSC) with cooling rates up to 1500 K/s and broadband dielectric spectroscopy (BDS) with frequencies up to 20 MHz are applied here to directly access both kinetics and dynamics of glass formation in a wide frequency range. For the first-time, the relation between the thermal vitrification and the dielectric relaxation is studied on vulcanized styrene-butadiene rubber, showing that both cooling rate and frequency dependence of its glass transition can be described by one single Vogel-Fulcher-Tammann-Hesse equation. The results indicate the validity of the Frenkel-Kobeko-Reiner equation. Another focus is the sample preparation of vulcanized elastomers for FDSC and BDS as well as the temperature calibration below 0°C. © 2020 The Authors. Journal of Applied Polymer Science published by Wiley Periodicals LLC
Estudio cinético del efecto de polifenilsulfona sobre el curado de una resina epoxi/amina mediante calorimetría diferencial de barrido convencional y modulada con temperatura: parte II
Variability of indices of macronutrient availability in soils at different spatial scales along an elevation transect in tropical moist forests (NE Ecuador)
Curing kinetics of phase separating thermosets studied by DSC, TMDSC and dielectric relaxation spectroscopy
Modulated temperature DSC measurements relating to the cold crystallization process of poly(ethylene terephtalate)
Kinetics of the glass transition of styrene‐butadiene‐rubber: Dielectric spectroscopy and fast differential scanning calorimetry
Temperature modulated DSC study of the kinetics of free radical isothermal network polymerization
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