Dendritic macromolecule and the preparation thereof

A dendritic macromolecule containing a core and branches emanating from the core through at least one generation, wherein said branches contain at least one unit selected from the group consisting of units according to the formula (2):

• ##STR15## wherein R represents H or --C.ident.N;
• R.sup.1 represents the core or a unit of the previous generation;
• R.sup.2 represents --H or --CH.sub.3 ;
• R.sup.3 represents ##STR16## R.sup.5 represents H or a unit of the next generation;
• R.sup.6 represents H or a unit of the next generation, wherein R.sup.5 and R.sup.6 in every ##STR17## group may be the same or different from one another, and fumaryl dinitrile, and the molecular weight is at least 1600, or in which the number of generations is 3-10, and wherein at least one branch contains units based on fumaryl dinitrile.

A process for the preparation of a dendritic macromolecule containing a core and branches, which comprises steps a) through c):

• a) providing a core having at least one functional group and allowing substantially every functional group of the core to react with a monomeric vinyl-cyanide unit;
• b) substantially every incorporated nitrile unit is reduced to an amine group in the presence of a heterogeneous metal-containing hydrogenation catalyst, which catalyst comprises at least a metal from group VIII of the periodic system of the elements, and H.sub.2 gas;
• c) substantially every amine group is caused to react with monomeric vinyl-cyanide units;
• wherein steps b) and c) are reiteratively and alternately carried out (N-1) times wherein 2.ltoreq.N.ltoreq.10.