Gelation of telechelic trimethoxysilyl-terminated polyoxazolines

Summary

Telechelic bifunctional polyoxazoline (poly(N-acetylethylenimine), PAEI) was prepared by ring-opening polymerization of 2-methyl-2-oxazoline (1) in the presence ofp-(α,α′-dibromo)xylene (2) as an initiator. The terminal propagating ends of this polyoxazoline were reacted with 3-aminopropyltrimethoxysilane (4) to give telechelic trimethoxysilyl-terminated polyoxazoline (5). Gelation of this telechelic polymer was carried out by hydrolysis and condensation of alkoxysilyl groups. By this method, the PAEI gels were obtained in good yields, and their degrees of swelling in the solvent could be controlled successfully by the feed ratios of the initiator to the monomer in the stage of the polymerization of 2-methyl-2-oxazoline. However, the cross-linked products were not stable and gradually dissolved in water. The gels were also swollen inN,N-dimethyl-formamide (DMF). The degrees of swelling of these gels were thus measured in DMF.