PROTECTION AND POLYMERIZATION OF FUNCTIONAL MONOMERS - ANIONIC LIVING POLYMERIZATION OF (2,2-DIMETHYL-1,3-DIOXOLAN-4-YL)METHYL METHACRYLATE

The two hydroxy groups of 2,3-dihydrolrypropyl methacrylate (1) were protected in the dioxolane form, (2,2-dimethyl-1,3-dioxolan-4-yl)methyl methacrylate (2). Anionic polymerization of 2 was investigated in THF at -78 degrees C with 1,1-diphenylhexyllithium, 1,1-diphenyl-3-methylpentyllithium, and alpha,omega-dilithiooligostyrene in the presence or absence of LiCl as well as with 1,4-disodio- and 1,4-dipotassio-1,1,4,4-tetraphenylbutanes. The polymerization of 2 proceeded to give poly(2) quantitatively in each case. Particularly, lithio initiators with LiCl afforded the poly(2)s of predictable molecular weights and of very narrow molecular weight distributions (($) over bar M(w)/($) over bar M(n) <1.1). Furthermore, the sequential polymerization of tert-butyl methacrylate with the anionic propagating end of poly(a) gave the block copolymer in quantitative efficiency. This indicates that anionic polymerization of 2 proceeds without transfer and termination reactions to yield a living polymer. Complete hydrolysis of the acetal protective group of poly(2) produced water-soluble poly(1). Addition of 2 to poly(styryl)lithium capped with 1,1-diphenylethylene in the presence of LiCl gave the block copolymers, which were hydrolyzed to result in poly(styrene-b-1) and poly(1-b-styrene-b-1) containing hydrophobic and hydrophilic segments.