Journal
JOURNAL OF PHYSICS D-APPLIED PHYSICS
Volume 44, Issue 4, Pages -Publisher
IOP PUBLISHING LTD
DOI: 10.1088/0022-3727/44/4/045403
Keywords
-
Categories
Ask authors/readers for more resources
The molecular dynamics in hydrated cellulose has been investigated by a combination of thermal analyses and dielectric spectroscopy. Differential scanning calorimetry shows the dependence upon hydration of the glass transition temperature T-g. A physical ageing phenomenon has been observed. At the molecular scale, bound water is hydrogen bonded to polar sites of cellulose macromolecules. At the macroscopic scale, water molecules play the role of a plasticizer for cellulose lowering its T-g. Dynamic dielectric spectroscopy combined with thermostimulated currents have allowed us to follow more localized molecular mobility. The beta relaxation mode is characterized by activation entropies that vanish for higher water contents indicating molecular mobility localization. It is plasticized by water like the glass transition. This analogy is explained by a common origin of both mechanisms: the mobility of the cellulose backbone. The evolution of the gamma mode upon hydration follows an anti-compensation law. Water acts as an anti-plasticizer in a hydrogen bonded network.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available