Estudo das propriedades reológicas de suspensões de atapulgita em poliéster.

Abstract

In this work the rheological properties of suspensions of attapulgite dispersed in an unsaturated polyesther resin were investigated by means of a Brookfield viscometer. The experiments were conducted at room temperature (23± 2°C) and atmospheric pressure (= 0,94 atm) for suspension concentrations of 0, 10, 20, 25, 26, 28 and 30g attapulgite/100 ml polyesther resin respectively. The rheological properties of these suspensions namely, shear stress, strain rate, apparent viscosity and power law index were then determined. The results show that, for the concentration range employed, the suspensions of attapulgite in polyesther exhibited a Newtonian behaviour, that is their apparent viscosity remained practically constant for all strain rates employed and their power law index had values close to one. The mathemathical models developped by taking into account the Newtonian characteristics of these suspensions were efficient on describing the rheological behaviour of the attapulgite/polyesther system investigated.