Block copolymers containing at least one block (A) of units from a C4-10C conjugated diene or 8-12C vinyl aromatic and at least one block (B) of units from a la

摘要

Block copolymers containing at least one block (A) of units from a C4-10C conjugated diene or 8-12C vinyl aromatic and at least one block (B) of units from a lactone (I) where R, R" are aliphatic, cycloaliphatic, alkenyl, cycloalkenyl os aromatic, R' is H or CH2R and in the latter case R" is non-existent; 1, 3 or 4; the total of C in R, R' and R" does not exceed 12. Preparation is by polymerising the monomer of (A) using a lithium catalyst, adding the Li-containing polymer to the lactone and carrying out a further polymerisation. In each polymerisation the temperature is between -29 deg.C and 149 deg.C, especially between -1 deg. and 121 deg.C.