ANIONIC-POLYMERIZATION OF ACRYLATES .7. POLYMERIZATION OF BUTYL ACRYLATE INITIATED BY THE LITHIUM ESTER ENOLATE LITHIUM TERT-BUTOXIDE COMPLEX

The anionic polymerization of butyl acrylate initiated by the complex initiator tert-butyl 2-lithioisobutyrate/lithium tert-butoxide (mole r atio 1:3 or 1:10) was studied in toluene, tetrahydrofuran and their mi xtures (9:1 or 19:1 v/v) at -60-degrees-C. The extent of autoterminati on increases with increasing content of THF; in neat THF the limiting conversion is only ca 70%. In neat toluene, the prepared polymers have broad or even multimodal MWD; conversion curves indicate a slow initi ation step. M(W)/M(n) ratio of the polymers prepared in THF and in the mixed solvents was 1.7 and 1. 12 - 1.35, respectively. In the mixed s olvents the molecular weight of the polymers rises virtually linearly with increasing conversion; semilogarithmic kinetic plots indicate tha t the polymerization proceeds in the manner not too far from a living process.