Patent ID: 7105626

Claim:
A method for preparing an end-capped polycarbonate, comprising the step of: combining a polycarbonate having free terminal OH groups with an end-capping reagent comprising a symmetrical activated carbonate and a compound A, wherein compound A has the structure, wherein R 1 is selected from the group consisting of a branched C 8 –C 40 alkyl and a linear C 8 –C 40 alkyl; and R 2 is selected from the group consisting of hydrogen, a branched C 3 –C 40 alkyl, a linear C 1 –C 40 alkyl, C 6 –C 30 aryl, and C 7 –C 30 , aralkyl group, or wherein compound A is an esterified polyol having the formula C(COCOR 3 ) 4 wherein R 3 is a C 10 –C 40 alkyl or a C 10 –C 40 alkenyl group, whereby the end-capping reagent reacts with at least some of the free hydroxyl end groups of the polycarbonate to produce an end-capped polycarbonate comprising optionally substituted aliphatic ester end groups.