Dielectric relaxation spectrum of poly (epsilon-caprolactone) networks hydrophilized by copolymerization with 2-hydroxyethyl acrylate.
Eur Phys J E Soft Matter
; 22(4): 293-302, 2007 Apr.
Article
em En
| MEDLINE
| ID: mdl-17415514
ABSTRACT
The dielectric relaxation spectrum of polycaprolactone (PCL) networks hydrophilized with different amounts of 2-hydroxyethyl acrylate (HEA) is investigated. PCL is a semicrystalline polyester with a complex relaxation spectrum that includes the main alpha relaxation and two secondary modes (beta, gamma) at lower temperatures. The overlapping of the different relaxational modes was split by using several Havriliak-Negami functions. Crosslinking the material modifies the dynamics of the main relaxation process as reflected by the parameters that characterize the Vogel behavior of the process and the dynamic fragility. The incorporation of HEA units in the network results in a material with microphase separation two alpha processes are detected, the one corresponding to the PCL chains and the new one associated to nanometric regions that contain different amount of both comonomers. The incorporation of the HEA units in the system involves the presence of a new beta(sw) relaxation due to the link of two side chains by water molecules through hydrogen bonding.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Poliésteres
/
Materiais Biocompatíveis
/
Acrilatos
Idioma:
En
Revista:
Eur Phys J E Soft Matter
Assunto da revista:
BIOFISICA
Ano de publicação:
2007
Tipo de documento:
Article
País de afiliação:
Espanha