Natureza das interações celulose-água / Nature of cellulose-water interaction

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

This dissertation aims to contribute to understand the interaction between two hydrophilic substances water and cellulose whose properties are strongly influenced by hydrogen bonding. Hydrogen bonds, HB, are present in cellulose fibers reinforcing the interior of the polymeric chain and allowing for high adherence among these chains. These intra and inter HB has been considered by some authors as a factor that contributes to the high mechanical stability of cellulose fibers. The water properties are unique among liquids with low molecular weight: high boiling point, lower density in the solid state phase than in the liquid phase and even at temperatures above 273K, water does not behave as a liquid in restricted space. If confined by two surfaces, the confined water behaves as an excellent adhesive. The understanding of systems involving hydrophilic materials, such as solids, gels, macromolecules, and water contributes to both the development of new materials and the understanding of live systems. This dissertation is a contribution to the understanding of the interaction among cellulose fibers and water. The results obtained with short and fine cellulose fibers show the presence of confined water exhibiting its characteristic transition in -45 º C (228K). This evidence is corroborated by the absence of this transition when the salts which breaks the LHs and thus, prevent the formation of confined water are present in the system formed by the cellulose and water.

ASSUNTO(S)

celulose cellulose hydrogen bonds water pontes de hidrogênio Água

ACESSO AO ARTIGO

Documentos Relacionados