THERMOGELATION OF METHYLCELLULOSE IN AQUEOUS-SOLUTIONS

Aqueous solutions of methylcellulose (MC) were studied as a function o f temperature. It is well known that semi-dilute MC solutions are form ing a gel upon heating. The gelation phenomenon is time-dependent and reversible but with a hysteresis. Different cyclic thermal treatments were conducted characterizing the formation of progressive interaction s. An aggregation above 35 degrees C is also shown by studies in dilut e solution.Moreover, the role of the chemical structure (distribution of substituents and degree of substitution value) on the MC rheologica l properties was underlined. Gelation is then mainly attributed to hyd rophobic interactions.