New Limited Molecular Weight Polymeric Dispersants Prepared by Melt Condensation Polymerization

Abstract

In this work, poly(sebacic anhydride) was prepared in a new method of condensation polymerization of sebacic acid monomer and sebacoyl chloride monomer in presence of triethyl amine, this polymer was purified, characterized by infrared spectroscopy.

Poly(sebacic anhydride) was used to prepare poly(ethylene glycol)-sebacic acid copolymers with carboxylic end groups and limited molecular weight using poly(ethylene glycol) having different chain length (400, 2000, 10000 and 20000 g/mole) by melt condensation polymerization. The copolymers were purified, characterized by infrared spectroscopy and end-group analysis of molecular weight determination technique. These polymers were tested as dispersants for ceramic alumina particles in ethanol as dispersion medium using centrifugation settlement method; High packing densities for alumina particles were obtained. It was found that the packing densities of alumina particles have been influenced by the polymer concentration and poly) ethylene glycol) chain length.

Their adsorption isotherms were also determined, it was found that the adsorption is molecular weight dependent and linear relationship was obtained between the maximum adsorption of the polymers and their molecular weights.

Keywords: melt condensation, poly(sebacic anhydride), poly(ethylene glycol)-sebacic acid, alumina, dispersants, isotherm adsorption