Living cationic polymerization of alkyl vinyl ethers
AssigneeE. I. Du Pont de Nemours and Company
InventorsChang Cho, Ben-Ami Feit, Owen W. Webster
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Abstract
This invention relates to a process for the living cationic polymerization of vinylic unsaturated compounds containing electron donating substituents resulting in polymers of narrow molecular weight distribution.
Claims20
A process for the living cationic polymerization of vinylic unsaturated monomers containing electronic donating substituents, comprising contacting said vinylic unsaturated monomers under polymerizing conditions at a temperature of about -80.degree. C. to about 0.degree. C. in a suitable solvent, in the presence of an initiating combination consisting essentially of a Lewis base selected from the group consisting of CH.sub.3 SR.sup.1, wherein:
- R.sup.1 is straight chain C.sub.1 to alkyl;
- (CH.sub.3 CH.sub.2).sub.2 S;
- (CH.sub.3 CH.sub.2 CH.sub.2).sub.2 S;
- (CH.sub.3).sub.2 SSCH.sub.2 SCH.sub.3 ;
- CH.sub.3 CH.sub.2 SH;
- (CH.sub.3).sub.2 SO;
- CH.sub.3 SCH.sub.2 SCH.sub.3 ;
- CH.sub.3 SCH.sub.2 CH.sub.2 SCH.sub.3 ;
- tetrahydrothiophene:
- tetrahydrofuran:
- diisopropyl sulfide:
- and p-dioxane, and a second component selected from:
- a proton source;
- a proton source and a Lewis acid;
- a carbenium or siliconium ion source;
- and a carbenium or siliconium ion source and a Lewis acid;
- provided that when the Lewis base is dioxane, the Lewis acid RAICL.sub.2, where R is C.sub.1 to C.sub.4 alkyl, is not present.
Dependencies are inferred from the claim text.