Protected functional initiators for making terminally functionalized polymers

Abstract

The anionic polymerization of unsaturated monomers with functionalized initiators having the structure R.sup.1 R.sup.2 R.sup.3 Si--O--A'--Li is improved by selecting A' from the structures --CH.sub.2 --CH.sub.2 --CH.sub.2 --(1,3-propyl), --CH.sub.2 --CH(CH.sub.3)--CH.sub.2 --(2-methyl-1,3-propyl), --CH.sub.2 --C(CH.sub.3).sub.2 --CH.sub.2 --(2,2-dimethyl-1,3-propyl), or --CH.sub.2 --CH.sub.2 --CH.sub.2 --CH.sub.2 --CH.sub.2 --CH.sub.2 --CH.sub.2 --CH.sub.2 --(1,8-octyl). This narrow class of polymerization initiators operate at surprisingly higher polymerization temperatures with surprisingly lower amounts of dead initiator than similar initiators wherein A' is --CH.sub.2 --CH.sub.2 --CH.sub.2 --CH.sub.2 --(1,4-butyl), --CH.sub.2 --CH.sub.2 --CH.sub.2 --CH.sub.2 --CH.sub.2 --(1,5-pentyl), or --CH.sub.2 --CH.sub.2 --CH.sub.2 --CH.sub.2 --CH.sub.2 13 CH.sub.2 --(1,6-hexyl).

Dependencies are inferred from the claim text.