Artigo de Periódico
Temperature-induced thickening of sodium carboxymethylcellulose and poly(N-isopropylacrylamide) physical blends in aqueous solution
Fecha
2012Registro en:
0170-0839
v. 69, n. 9
Autor
Vidal, Rosangela Regia Lima
Lima, Bruna V. de
Marques, Nívia do N.
Maia, Ana M. S.
Balaban, Rosangela de C.
Vidal, Rosangela Regia Lima
Lima, Bruna V. de
Marques, Nívia do N.
Maia, Ana M. S.
Balaban, Rosangela de C.
Institución
Resumen
This study describes the synthesis of poly(N-isopropylacrylamide) (PNIPAM) via free radical polymerization, the preparation of physical blends containing sodium carboxymethylcellulose (CMC) and PNIPAM in aqueous solution, at total polymer concentrations of 2 and 6 g/L in different compositions, and applies rheology to investigate interactions between PNIPAM and CMC compared to pure polymers, in aqueous solution. Rheological measurements indicated thermothickening behavior for the 50 % PNIPAM–50 % CMC physical blend in aqueous solution, at 6 g/L, as viscosity rose when temperature was increased to a range of 25–40 °C. Similar thermothickening behavior was observed for the 25 % CMC–75 % PNIPAM physical blend in solution, at a total polymer concentration of 2 g/L. These results provide new information for preparing physical blends in aqueous solutions exhibiting thermothickening behavior, indicating that this behavior depends on total polymer concentration and composition of the mixture.