A polymer composition comprising aliphatic polycarbonate chains having two or more sites of olefinic unsaturation, wherein a) sites of olefinic unsaturation are disposed at one or more ends of the aliphatic carbonate chains, comprising aliphatic polycarbonate chains having a formula: wherein: each Y is independently a functional group containing olefinic unsaturation n is an integer from 4 to 1,000, z is a multivalent moiety, x and y are each independently an integer from 0 to 6, where the sum of x and y is between 2 and 6, and wherein R 1, R 2, R 3, and R 4 are, at each occurrence in the polymer chain, independently selected from the group consisting of -H, fluorine, a C 1-30 aliphatic group, and a C 1-20 heteroaliphatic group, and a C 6-10 aryl group, where any two or more of R 1, R 2, R 3, and R 4 may optionally be taken together with intervening atoms to form one or more rings optionally containing one or more heteroatoms; b) at least two of the sites of olefinic unsaturation in Y comprise carbon-carbon double bonds in a moiety selected from the group consisting of: optionally substituted acrylate, optionally substituted acrolein, optionally substituted acrylamide, optionally substituted maleimide, optionally substituted vinyl ether, and optionally substituted styrene, wherein each Y is independently selected from the group consisting of: wherein: R a, R b, and R c are independently selected from the group consisting of -H, a C 1-20 aliphatic group, a C 1-20 heteroaliphatic group, an acyloxy group, an acyl group, and an alkoxy group; q is from 1 to 6, inclusive; R a' is at each occurrence independently selected from the group consisting of: halogen, C 1-20 aliphatic, and C 1-20 heteroaliphatic; p is an integer from 1 to 6 inclusive; and c) the molecular weight M n of the aliphatic polycarbonate chains is on average in the range of 500 g/mol to 100,000 g/mol measured as indicated in the description. a) sites of olefinic unsaturation are disposed at one or more ends of the aliphatic carbonate chains, comprising aliphatic polycarbonate chains having a formula: wherein: each Y is independently a functional group containing olefinic unsaturation n is an integer from 4 to 1,000, z is a multivalent moiety, x and y are each independently an integer from 0 to 6, where the sum of x and y is between 2 and 6, and wherein R 1, R 2, R 3, and R 4 are, at each occurrence in the polymer chain, independently selected from the group consisting of -H, fluorine, a C 1-30 aliphatic group, and a C 1-20 heteroaliphatic group, and a C 6-10 aryl group, where any two or more of R 1, R 2, R 3, and R 4 may optionally be taken together with intervening atoms to form one or more rings optionally containing one or more heteroatoms; each Y is independently a functional group containing olefinic unsaturation n is an integer from 4 to 1,000, z is a multivalent moiety, x and y are each independently an integer from 0 to 6, where the sum of x and y is between 2 and 6, and wherein R 1, R 2, R 3, and R 4 are, at each occurrence in the polymer chain, independently selected from the group consisting of -H, fluorine, a C 1-30 aliphatic group, and a C 1-20 heteroaliphatic group, and a C 6-10 aryl group, where any two or more of R 1, R 2, R 3, and R 4 may optionally be taken together with intervening atoms to form one or more rings optionally containing one or more heteroatoms; b) at least two of the sites of olefinic unsaturation in Y comprise carbon-carbon double bonds in a moiety selected from the group consisting of: optionally substituted acrylate, optionally substituted acrolein, optionally substituted acrylamide, optionally substituted maleimide, optionally substituted vinyl ether, and optionally substituted styrene, wherein each Y is independently selected from the group consisting of: wherein: R a, R b, and R c are independently selected from the group consisting of -H, a C 1-20 aliphatic group, a C 1-20 heteroaliphatic group, an acyloxy group, an acyl group, and an alkoxy group; q is from 1 to 6, inclusive; R a' is at each occurrence independently selected from the group consisting of: halogen, C 1-20 aliphatic, and C 1-20 heteroaliphatic; p is an integer from 1 to 6 inclusive; and R a, R b, and R c are independently selected from the group consisting of -H, a C 1-20 aliphatic group, a C 1-20 heteroaliphatic group, an acyloxy group, an acyl group, and an alkoxy group; q is from 1 to 6, inclusive; R a' is at each occurrence independently selected from the group consisting of: halogen, C 1-20 aliphatic, and C 1-20 heteroaliphatic; p is an integer from 1 to 6 inclusive; and c) the molecular weight M n of the aliphatic polycarbonate chains is on average in the range of 500 g/mol to 100,000 g/mol measured as indicated in the description.