DENDRITIC RESINS FOR COATING APPLICATIONS

Hyperbranched, aliphatic polyesters of theoretically calculated molar masses 1 200-44 300 (2-7 generations) were synthesized in the molten s tate from 2,2-bis(hydroxymethyl)propionic acid (bis-MPA) (repeating un it of AB(x)-type) and 2-ethyl-2-(hydroxymethyl)-1,3-propanediol (TMP) (core molecule) using acid catalysis. The synthetic procedure was a ps eudo-one-step divergent reaction. The degree of branching was found to be near 80 %. A study has also been made with respect to the theologi cal properties of the hyperbranched aliphatic polyesters. The polymers exhibit an almost newtonian behaviour in the molten state. They also exhibit a lower increase in viscosity with molecular weight than linea r polymers. The surface functionality is shown to greatly affect the v iscosity of the polymers.