Process and catalyst for hydrogen mediated saline hydride initiated anionic chain transfer polymerization

A process for anionic chain transfer polymerization comprising feeding a vinyl aromatic and/or conjugated diene monomer under an atmosphere comprising hydrogen to a reaction mixture in a reactor vessel, wherein said reaction mixture was formed from (a) an organolithium compound;

• (b) a polytertiaryamine compound;
• (c) an alkoxide, wherein said alkoxide is an alkali metal alkoxide, or a magnesium alkoxide;
• (d) an optional aromatic hydrocarbon having at least one C—H covalent bond pKa within the range of 2.75 pKa units above that of the pKa of toluene to −4.30 pKa units below the pKa of toluene;
• and in (e) a hydrocarbon solvent having a pKa greater than H2, wherein the partial pressure of hydrogen is maintained at pressures between about 1.0 Bar to about 19.0 Bar, the molar ratio of the alkoxide to organolithium compound charged in the reactor is in the range of about 0.25:1 to about 10:1;
• the molar ratio of monomer to organolithium compound is about 10:1 to about 1000:1, and the molar ratio of the tertiary amine to organolithium compound is in the range of about 1.5:1 to about 20:1 and the hourly feed rate of monomer to organolithium is in the range of 10 to 200 moles of monomer per hour per mole of organolithium.