Block copolymers containing polymerized lactone segments

Claim 1

A process comprising (a) providing a first product by reacting an organoalkali metal compound with at least one monomer with which it is reactable to form a base polymer, said base polymer being formed from at least one of the monomers selected from the group consisting of conjugated dienes having 4 to 12 carbon atoms per molecule and monovinyl aromatic compounds having 8 to 13 carbon atoms per molecule; (b) providing a second product by reacting the first product with an oxirane compound with which it is reactable; said oxirane compound containing 1 to 10 oxirane or epoxy groups per molecule and being provided in an amount of at least 0.1 oxirane group per alkali metal atom in the first product; (c) providing a third product by reacting the second product with a metal compound with which it is reactable, said metal compound being provided in an amount of at least 0.1 atoms metal in the metal compound for each atom alkali metal in the second product, said metal compound represented by the formula X.sub.n --M--R.sub.v-n where M represents a metal selected from the group consisting of Al, Sn, Zn, Cd, Ge, Si and Ti; R represents a monovalent essentially hydrocarbyl radical containing from 1 to 20 carbon atoms, X represents a monovalent basic moiety capable of abstracting the alkali metal from the second product; v is the valence of M and n is at least one and represents the number of X groups connected to M; and (d) providing a fourth product by reacting the third product with at least one lactone with which it is reactable, said lactone having from 3 to 20 carbon atoms per molecule.