PREPARATION AND PROPERTIES OF POLY (ALKYL VINYL ETHER-2-ETHYL-2-OXAZOLINE) DIBLOCK COPOLYMERS

A method for the synthesis of well-defined poly(alkyl vinyl ether-2-ethyl-2-oxazoline) diblock copolymers with hydrolytically stable block linkages has been developed. Monofunctional poly (alkyl vinyl ether) oligomers with nearly Poisson molecular weight distributions were prepared via a living cationic polymerization method using chloroethyl vinyl ether together with HI/ZnI2 as the initiating system and lithium borohydride as the termination reagent. Using the resultant chloroethyl ether functional oligomers in combination with sodium iodide as macroinitiators, 2-ethyl-2-oxazoline was polymerized in chlorobenzene/NMP to afford diblock copolymers. A series of poly(methyl vinyl ether-2-ethyl-2-oxazoline) diblock materials were found to have polydispersities of almost-equal-to 1.3-1.4 and are microphase separated as indicated by two T(g)'s in their DSC thermograms. These copolymers are presently being used as model materials to study fundamental parameters important for steric stabilization of dispersions in polar media.