NEW LIGANDS FOR THE LIVING HIGH-MOLECULAR-WEIGHT ANIONIC (CO)POLYMERIZATION OF ACRYLATES IN TOLUENE AT 0 DEGREES-C - 3 - LIGATION OF SEC-BUTYLLITHIUM BY LITHIUM SILANOLATES

sec-Butyllithium combined with a new family of ligands, (i.e., lithium silanolates), has been used to initiate the ligated anionic polymeriz ation of n-butyl acrylate (BuA) in toluene at low temperature. Compare d to other mu-ligands, sBuMe(2)SiOLi is a more efficient stabilizer of the active centers. Thus, under selectively chosen reaction condition s, the polymerization proceeds quantitatively at -40 degrees C, produc ing a high-molecular-weight polymer with narrow-molecular-weight distr ibution (<(M-W)over bar>/<(M-n)over bar>, < 1.2). When the copolymeriz ation of BuA is initiated by a living {PMMALi, 5.sBuDLi} in toluene at -78 degrees C, the experimental data agree with a well-controlled blo ck copolymerization reaction, since the final molecular-weight distrib ution is very narrow (<(M-W)over bar>/<(M-n)over bar> less than or equ al to 1.1) and the polymerization efficiency very high.