Patent ID: 7323528

Claim:
A process for producing a block copolymer, comprising: heating a mixture of styrene and an unsaturated cyclic anhydride (UCA) in the presence of a free radical initiator and a stable free radical at temperatures between about 110 and about 200° C. to form a block copolymer in a single monomer-addition step, adjusting or setting the ratio of initiator to monomer in order to control the total length of the block copolymer, cooling the reaction mixture; and recovering the block copolymer by isolating the block copolymer from un-reacted monomer, wherein the composition of the block copolymer comprises: a first block comprising a random copolymer of styrene and unsaturated cyclic anhydride having a total length between about 1 and about 720 monomeric units; and a second block comprising an essentially pure polystyrene block having a length between about 100 and about 2000 monomeric units, wherein the polydispersity of the block copolymer is between about 1.2 and about 3, and wherein the resulting block copolymer has a number average molecular weight greater than about 25,000.