Zakład Fizyki Makromolekularnej
Strona główna
Zespół
Badania
Aparatura
Seminaria
Publikacje
Nasze
konferencje
Aktywność
konferencyjna
Projekty
Programy
Najbliższe
wydarzenia
Linki
Kontakt

wizyta

od 2020-09-20


Authors: Makrocka-Rydzyk M., Nowaczyk G. , Głowinkowski S., Jurga S.

Title: Dynamic mechanical study of molecular dynamics in ethylene-norbornene copolymers

Source: Polymer

Year : 2010


Abstract:

Dynamic mechanical studies of Molecular dynamics have been performed for two ethylene-norbornene copolymers. The analysis of data indicates the existence of three relaxation processes: a primary (alpha) and two secondary (beta and gamma) ones. It was found that the secondary processes beta and gamma are connected with the local motions of ethylene and norbornene groups, respectively and that their rates follow the Arrhenius relation. Moreover, the beta process was recognized as the Johari-Goldstein process acting as the precursor of the cooperative structural alpha-relaxation. Contrary to gamma and beta processes, the motional rate of alpha-one follows the Vogel-Fulcher-Tammann equation indicating the cooperative nature of motions involved in this process. An increase in norbornene content in copolymer slows down the molecular dynamics of both norbornene fragments and whole chains, and in consequence shifts these relaxation Processes into higher temperatures. Using the Havriliak-Negami formalism the motional parameters for the processes mentioned above were estimated.
(C) 2009 Elsevier Ltd. All rights reserved.

DOI: 10.1016/j.polymer.2009.12.027   (Pobrane:  aktualizowanie)

 © Opisy i zdjęcia: Zakład Fizyki Makromolekularnej  | Ta stona używa ciasteczek
     Zaktualizowano: podstrony  2021-06-21  / bazę danych:   2021-08-30  by Webmaster: Zbigniew Fojud