Avaliação de géis obtidos a partir da acetilação da quitosana em meio heterogêneo

Química Nova

Rosangela Balaban Garcia²  Dayse Luzia Pinheiro Da Silva²  Marta Costa²  Fernanda Nervo Raffin¹  Naira Machado Da Silva Ruiz¹ 

[1] ,Universidade Federal do Rio Grande do Norte Departamento de Química Natal RN ,Brasil

关键词: chitosan;    gel;    rheology;   

DOI  :  10.1590/S0100-40422008000300004

来源: SciELO

【 摘 要 】

Chitosan was acetylated during 2, 5 and 10h and physical gels were obtained at different polymer concentrations in N,N-dimethylacetamide containing 5% of LiCl. Acetylation was confirmed by infrared spectroscopy and 13C NMR, and degrees of acetylation in the range of 0.82-0.91 were determined by NMR. The O-acetylation degree (0.12-0.15) was exclusively determined by a volumetric method. Rheological studies showed that the storage modulus values were smaller for the more acetylated samples and increased with the temperature and the polymer concentration. All the gels presented storage modulus superior to loss modulus, evidencing more elastic than viscous characteristics. The results obtained in this work suggest a gelation process based on a balance between O and N-acetylation and intermolecular bonds.

【 授权许可】

CC BY-NC   
 All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License