Hydration properties of regioselectively etherified celluloses monitored by 2H and 13C solid-state MAS NMR spectroscopy.
Carbohydr Polym
; 89(2): 640-7, 2012 Jun 20.
Article
en En
| MEDLINE
| ID: mdl-24750769
ABSTRACT
The hydration properties of 2,3-O-hydroxypropylcellulose (HPC) and 2,3-O-hydroxyethylcellulose (HEC) were analyzed by multi-nuclear solid-state MAS NMR spectroscopy. By 13C single-pulse (SP) MAS and cross-polarization (CP) MAS NMR, differences between the immobile regions and all parts of the polysaccharides were detected as a function of hydration. Complementary information about the water environments was observed by 2H MAS NMR. By this approach it was demonstrated that side chains in 2,3-O-HPC and 2,3-O-HEC were easier to hydrate than the cellulose backbone. Furthermore the motion of water was more restricted (slower) in 2,3-O-HPC than in 2,3-O-HEC. For both polysaccharides the hydration could be explained by a two-step process in step one increased ordering of the immobile regions occurs after which the entire polymer is hydrated in step two.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Celulosa
/
Óxido de Deuterio
Idioma:
En
Revista:
Carbohydr Polym
Año:
2012
Tipo del documento:
Article
País de afiliación:
Dinamarca