Multifunctional initiator from divinyl dislane
AssigneeShell Oil Company
InventorsLinda R. Chamberlain, Ronald J. Hoxmeier, Philip A. DeFriend
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Abstract
A multifunctional initiator is prepared by contacting an organo-alkali metal compound with a silane represented by the formula: ##STR1## wherein the R' are generally lower alkyl groups such as methyl and the R" is generally an .paren open-st.CH.sub.2 .paren close-st..sub.n group with n=2. Superior results are obtained presumably because of the separation of the vinyl groups and the greater solubility of the compound because of the R' groups. The resulting catalyst initiates polymerization of monomers such as conjugated dienes and monovinyl substituted aromatic compounds to give relatively monodispersed polymers with little or no crosslinking.
Claims20
A process for forming a multifunctional initiator in a reaction zone comprising:
- contacting an organo-alkali metal compound with a silane represented by the formula ##STR4## wherein each R' is individually selected from the group consisting of 1-20 carbon atom alkyl groups, 6-10 carbon atom aryl groups and H with the provision that no more than two of the R' groups are H, and no more than 1 H is on either Si;
- wherein R" is an .paren open-st.CH.sub.2 .paren close-st..sub.n moiety where n=1 to 20;
- wherein said contacting is carried out in the presence of a promoter selected from the group consisting of ethers and amines, said promoter being present in an amount of at least 0.1 moles per mole of said organo-alkali metal compound.
A method comprising contacting secondary butyllithium with 1,4-divinyl-1,1,4,4-tetramethyldisilylethylene in a cyclohexane polymerization solvent in the presence of 0.04-10 moles of 1,2-dimethoxyethane per mole of said secondary butyllithium to produce a multifunctional initiator in situ, thereafter introducing a monomer selected from the group consisting of isoprene, butadiene and styrene into said polymerization zone to give a polymerization mixture and maintaining said polymerization mixture under polymerization conditions for a time sufficient to give a polymer.
A composition represented by the formula ##STR5## wherein each R is selected from the group consisting of 1-20 carbon atom alkyl groups, 1-20 carbon atoms cycloalkyl groups, and 6-10 carbon atoms aryl groups;
- each R' is individually selected from the group consisting of 1-20 carbon atom alkyl groups, 6-10 carbon atom aryl groups and H with the provision that no more than 2 of the R' groups are H;
- and no more than one H group is on either Si;
- and
- wherein R" is an .paren open-st.CH.sub.2 .paren close-st..sub.n moiety where n=1 to 20.
Dependencies are inferred from the claim text.