Biocompatible Elastomers with Crosslinked Structure

Among other things, the present disclosure provides compositions and methods for an elastomeric cross-linked polyester material. Such an elastomeric cross-linked polyester material, in some embodiments, comprises a plurality of polymeric units of the general formula (-A-B-)p, wherein p is an integer greater than 1; and a plurality of urethane cross-links each of which covalently links two polymeric units to one another, which two linked polymeric unit each had at least one free hydroxyl or amino group prior to formation of the crosslink.