Abstract
Dendritic methacrylic crosslinking agents were synthesized by modification of amino functional poly(propyleneimine) dendrimers. On the basis of model reactions, several experimental methods for the introduction of methacrylate end groups were evaluated. In case of the Michael reaction of 2‐(acryloyloxy)ethyl methacrylate (1) the amino‐end groups of the dendrimers of the second, the fourth or the fifth generation add exclusively onto the acrylic double bonds of 1 forming methacrylic end groups in the modified dendrimers. The quantitative and uniform conversion could be proved by NMR spectroscopy. Analogous dendrimer modifications were carried out with mixtures of 1 and other acrylates. The dendrimeric methacrylates of different generations were polymerized in solution and bulk at 80°C with 2.2′‐azoisobutyronitrile as initiator. The polymerization enthalpy of the dendrimeric methacrylates was determined by differential scanning calorimetry and shows that the polymerization of approximately every double bond takes place. The polymerization of methacrylic dendrimers yields crosslinked polymers with glass transition temperatures near or below room temperature.