| 主权项 |
1. An AB-, ABA-, or BAB-block copolymer composition, said block copolymer comprising:
at least a first AB, ABA, or BAB block copolymer component comprising a first hydrophobic A-block and a first hydrophilic B-block, wherein the first hydrophobic A-block is a biodegradable polyester comprising about 60% to 95% caprolactone by mole percent and at least one second polyester-forming monomer, and the first hydrophilic B-block has a first average molecular weight and comprises polyethylene glycol; at least a second AB, ABA, or BAB block copolymer component comprising a second hydrophobic A-block and a second hydrophilic B-block, wherein the second hydrophobic A-block comprises biodegradable polyester, and the second hydrophilic B-block has a second average molecular weight and comprises polyethylene glycol, wherein the second average molecular weight is different from the first average molecular weight;
wherein the block copolymer composition has a total weight average molecular weight from 1500 to 10,000 Daltons, a total A-block content of the composition from about 60 to 85% by weight, and a total B-block content of the composition from about 15% to 40% by weight, wherein the total weight average molecular weight of the B-block in the composition is from 300 to 2000 Daltons, wherein the block copolymer composition is a powder or wax at room temperature, is capable of exhibiting reverse thermal gellation when formed as an aqueous polymer solution, and is capable of being converted into an aqueous polymer solution in less than thirty minutes by agitating without the use of additives or heat exceeding 60° C. |
