MULTIFUNCTIONAL INITIATORS FOR THE RUTHENIUM-MEDIATED LIVING RADICAL POLYMERIZATION OF METHYL-METHACRYLATE - DIFUNCTIONAL AND TRIFUNCTIONALDICHLOROACETATES FOR SYNTHESIS OF MULTIARMED POLYMERS

Bi- and trifunctional dichloroacetates were synthesized from the corre sponding multifunctional alcohols or phenols and-then employed as mult ifunctional initiators for the living radical polymerizations of methy l methacrylate mediated by RuCl2(PPh3)(3) in the presence of aluminum compounds such as Al(OiPr)(3) and Al(acac)(3) (acac: acetylacetonate). All these systems led to living polymerizations. However, the systems with Al(OiPr)(3) involved partial transesterification of the eater un its in the initiators, which resulted in the formation of a monofuncti onal initiator. In contrast, new systems with Al(acac)(3) did not indu ce such transesterification and produced the multiarmed living polymer s. H-1 NMR analysis showed that polymers obtained with the di-and trif unctional esters possessed almost two and three arms, respectively, al ong with controlled molecular weights and their narrow distributions.