Synthesis of multiblock polymers using group IIA and IIB metal cyclic organometallic initiators
AssigneeBridgestone Corporation
InventorJames E. Hall
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Abstract
The invention is a practical process for anionically synthesizing multiblock polymers containing a plurality of blocks formed from polar and/or non-polar monomers by using a cyclic organometallic compound initiator that comprises a divalent metal atom and an organic moiety contained in a ring, preferably a cycloorganomagnesium initiator. Activation of the ring metallic atom results in anionic polymerization of the monomers by addition into the initiator ring at the bonds between the metallic atom and its two adjacent carbon atoms, the metallic atom acting as a bridge between the two living ends of the propagating chain. The active chain ends can be coupled or terminated.
Claims23
A process for preparing a triblock polymer comprising the steps of (1) reacting a first monomer charge of at least one anionically polymerizable monomer with an initiator comprising a cyclic organometallic compound that comprises a divalent metal atom and an organic moiety contained in a ring, to form a first block having two terminal active ends (2) forming a triblock polymer by reacting a second monomer charge of at least one anionically polymerizable monomer with the first block to form a second block on each of the terminal active ends of the first block, said second monomer charge being dissimilar in composition to the first monomer charge.
Dependencies are inferred from the claim text.