STYRENE-TERMINATED POLY(VINYL ALCOHOL) MACROMONOMERS .1. SYNTHESIS BY ALDOL GROUP TRANSFER POLYMERIZATION

Aldol group transfer polymerization of t-butyldimethylsilyl vinyl ether initiated by an unsaturated compound, p-formylstyrene, and catalysed by zinc bromide allowed synthesis of styryl-silylated poly(vinyl alcohol) macromonomers bearing an aldehyde end-function. Various macromonomers with average degrees of polymerization up to 28 were prepared and characterized according to different analytical methods, such as H-1 and C-13 nuclear magnetic resonance and ultra-violet spectroscopy and gel permeation chromatography. In order to improve the stability of the end-group, the aldehyde function was reacted with a silylketene acetal compound, 1-methoxy-2-methyl-1-trimethylsiloxypropene, which leads to a beta-hydroxy ester end-group, much more stable towards side-reactions. Afterwards, the silyl ether side-groups were hydrolysed with tetrabutylammonium fluoride in order to obtain hydrophilic styryl-poly(vinyl alcohol) macromonomers.