| 摘要 |
A process for a double stage convergent synthesis of a polymeric polyalcohol substantially and preferably built up from polyester units and composed of a monomeric or polymeric core to which at least one hyperbranched dendritic branch (dendron) consisting of a number of branching generations is added. The branching generations comprise a polymeric or monomeric branching chain extender having three reactive functions of which two are hydroxyl groups and one is a carboxyl group. The two hydroxyl groups of the branching chain extender is in a first step ketal protected by reacting said two hydroxyl groups with a ketal. A second step includes protection of the carboxyl group of said branching chain extender. The ketal protected branching chain extender and the carboxyl protected chain extender are then employed for repeated addition in a number of step yielding a predetermined number of branching generations. The thus synthesized dendron is finally added to a core having reactive hydroxyl or epoxide groups and the ketal protected hydroxyl groups are optionally deprotected. |
