Thermoplastic elastomers of isobutylene and process of preparation
AssigneeThe University of Akron
InventorsJoseph P. Kennedy, Judit E. Puskas, Gabor Kaszas, William G. Hager
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Abstract
Block copolymers compose a polyisobutylene rubbery soft segment of M.sub.n of about 5,000 to above 500,000 and glassy hard segments of M.sub.n of about 5,000 or higher and usually about 10,000 to 35,000 or more, are made by preparing a living polymer block of the polyisobutylene and then polymerizing on said living polyisobutylene block the glassy hard segments by adding thereto an electron donor having a donor number of 15 to 50 and then adding and polymerizing the monomers for the glassy hard segments. The monomers for the glassy hard segments are styrene and its derivatives and indene and its derivatives and mixtures thereof.
Claims12
A living polymerization process for preparing linear or star-shaped block copolymers of isobutylene and another monomer comprising polymerization isobutylene alone or with another monomer at a temperature of about -10.degree. C. to -90.degree. C. in an anhydrous system of said isobutylene or another monomer, a mixed solvent, imitator and a metal halide selected from the metals of tin, titanium, aluminum, boron, said polymerization system being capable of producing an electron pair donor initiator having the formula:
- ##STR3## in which R.sub.1, R.sub.2 and R.sub.3 are alkyl, aryl, or aralkyl groups and can be the same or different and x is a carboxyl, alkoxyl, hydroxyl or halogen group, and i is a positive whole number, said mixed solvent being formed of at least one hydrocarbon or halohydrocarbon with or without an electron donor pair solvent having a donor number of about 15 to 50, when x is carboxyl or alkoxy;
- the mixed solvent being a mixture of hydrocarbon and halohydrocarbon with or without said electron donor pair solvent with said hydrocarbon or halohydrocarbon and when x is hydroxyl or halogen, the mixed solvent must contain an electron pair donor solvent of 15 to 50 donor number when said polymerization of another monomer occurs in the presence of the electron pair donor solvent, the mixed solvent and living polyisobutylene, said another monomer being selected from at least one of styrene, and its halo or alkyl styrenes, indene and alkylated indenes.
Dependencies are inferred from the claim text.