KOPAL, Ivan, Marta HARNIČÁROVÁ, Jan VALÍČEK, Pavel KOŠTIAL a Zora JANČÍKOVÁ. Determination of activation energy of relaxation events in thermoplastic polyurethane by dynamic mechanical analysis. Material Iwiss. Weinheim: Verlag GmbH, 2018, Neuveden, č. 48, s. 627-634. ISSN 0933-5137. |
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@article{44381, author = {Kopal, Ivan and Harničárová, Marta and Valíček, Jan and Koštial, Pavel and Jančíková, Zora}, article_location = {Weinheim}, article_number = {48}, keywords = {"Thermoplastic polyurethane; relaxation transitions; activation energy; dynamic mechanical analysis}, language = {eng}, issn = {0933-5137}, journal = {Material Iwiss}, title = {Determination of activation energy of relaxation events in thermoplastic polyurethane by dynamic mechanical analysis}, volume = {Neuveden}, year = {2018} }
TY - JOUR ID - 44381 AU - Kopal, Ivan - Harničárová, Marta - Valíček, Jan - Koštial, Pavel - Jančíková, Zora PY - 2018 TI - Determination of activation energy of relaxation events in thermoplastic polyurethane by dynamic mechanical analysis JF - Material Iwiss VL - Neuveden IS - 48 SP - 627-634 EP - 627-634 PB - Verlag GmbH SN - 09335137 KW - "Thermoplastic polyurethane KW - relaxation transitions KW - activation energy KW - dynamic mechanical analysis N2 - "In the present study, the activation energy associated with the primary and the secondary relaxation transition events in thermoplastic polyurethane has been determined using the multi-frequency dynamic mechanical analysis tests. The thermoplastic polyurethane under investigation was tested at temperatures between 145 K - 526 K, at frequencies of 0.5 Hz, 1 Hz, 2 Hz, 5 Hz and 10 Hz and at a constant heating rate of 3 K·min–1. It was observed that the studied materials show three relaxation events – glass transition of soft segments, glass transition of hard segments as well as secondary transition associated with short range order translation and with reorientational motions within the polyurethane crystals. The activation energies for all three observed relaxation events were determined from dynamic mechanical properties measured at various frequencies using a linearized Arrhenius equation. The calculated activation energy is 379.73 kJ·mol-1 for the glass transition of hard segments; for the secondary relaxation transition it is 65.53 kJ·mol-1 and for the glass transition of soft segments it is 45.98 kJ·mol-1." ER -
KOPAL, Ivan, Marta HARNIČÁROVÁ, Jan VALÍČEK, Pavel KOŠTIAL a Zora JANČÍKOVÁ. Determination of activation energy of relaxation events in thermoplastic polyurethane by dynamic mechanical analysis. \textit{Material Iwiss}. Weinheim: Verlag GmbH, 2018, Neuveden, č.~48, s.~627-634. ISSN~0933-5137.
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