caa a22 4500 463189175 CHVBK 20180406164903.0 cr unu---uuuuu 170326e20070501xx s 000 0 eng 10.1007/s10973-006-8038-8 doi (NATIONALLICENCE)springer-10.1007/s10973-006-8038-8 Watereffect in the thermal and molecular dynamics behavior of poly( L -lacticacid) [Elektronische Daten] [Ana Brás, María Viciosa, Madalena Dionísio, J. Mano] A detailed dielectric characterization of the relaxation modes found in a poly(L-lactic acid), PLLA, film containing 0.4 mass% of water is provided. The sub-glass relaxation process is a superposition of two processes, one highly influenced by water with activation energy of 50 kJ mol-1, and another one, with longer relaxation times and lower intensity having activation energy of 38 kJ mol-1. Dried PLLA exhibits an abnormally broad secondary β-relaxation that probably corresponds to the superposition of multiple processes. Upon water sorption the strength of the more mobile process significantly increases being shifted to lower temperatures which allows the detection of the underlying process. The glass transition relaxation process is deviated to higher frequencies almost one decade due to the water plasticizing effect. The reported results show that small quantities of water may have a profound impact in the relaxational features in PLLA, which should be taken in account when considering the properties and performance of this system. Springer-Verlag, 2007 dielectric relaxation nationallicence polyester nationallicence thermal treatment nationallicence water effect nationallicence Brás Ana REQUIMTE/CQFB, Departamento de Química, FCT, Universidade Nova de Lisboa, 2829-516, Caparica, Portugal aut Viciosa María REQUIMTE/CQFB, Departamento de Química, FCT, Universidade Nova de Lisboa, 2829-516, Caparica, Portugal aut Dionísio Madalena REQUIMTE/CQFB, Departamento de Química, FCT, Universidade Nova de Lisboa, 2829-516, Caparica, Portugal aut Mano J. 3B's Research Group - Biomaterials, Biodegradables, Biomimetics, Department of Polymer Engineering, University of Minho, Campus de Gualtar, 4710-053, Braga, Portugal aut Journal of Thermal Analysis and Calorimetry Kluwer Academic Publishers 88/2(2007-05-01), 425-429 1388-6150 88:2<425 2007 88 10973 https://doi.org/10.1007/s10973-006-8038-8 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10973-006-8038-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Brás Ana REQUIMTE/CQFB, Departamento de Química, FCT, Universidade Nova de Lisboa, 2829-516, Caparica, Portugal aut NATIONALLICENCE 700 1- Viciosa María REQUIMTE/CQFB, Departamento de Química, FCT, Universidade Nova de Lisboa, 2829-516, Caparica, Portugal aut NATIONALLICENCE 700 1- Dionísio Madalena REQUIMTE/CQFB, Departamento de Química, FCT, Universidade Nova de Lisboa, 2829-516, Caparica, Portugal aut NATIONALLICENCE 700 1- Mano J. 3B's Research Group - Biomaterials, Biodegradables, Biomimetics, Department of Polymer Engineering, University of Minho, Campus de Gualtar, 4710-053, Braga, Portugal aut NATIONALLICENCE 773 0- Journal of Thermal Analysis and Calorimetry Kluwer Academic Publishers 88/2(2007-05-01), 425-429 1388-6150 88:2<425 2007 88 10973 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer