Branched polymers by chemoenzymatic self condensing vinyl polymerization

The combination of enzymic polymn. with ATRP for the synthesis of branched (block) copolymers was investigated. Heterotelechelic polycaprolactone macroinimer was synthesized in a one-pot enzymic procedure by using 2-hydroxyethyl fN-bromoisobutyrate as a bifunctional initiator. A polymerizable end-group was introduced by subsequent in-situ enzymic acrylation with vinyl acrylate. The degree of end-group functionalization of the polycaprolactone macroinimer can be controlled by the water activity in the enzymic initiation step with the double headed initiator. The degrees of functionalization of the macroinimer with the ATRP initiator were between 83 and 97 %. In the acrylation step a functionalization of 80-90 % was achieved. Self condensing ATRP of the macroinimers was successfully conducted with and without the addn. of MMA as a comonomer as evident from the increase of mol. wt. upon ATRP.