Linear and crosslinked copolymers of a vinyl ether of ethylene glycol (2-hydroxyethyl vinyl ether, (1)) and butyl vinyl ether (2) are synthesized by y-irradiation polymerization. It is shown that the linear copolymers exhibit a phase separation phenomenon in dependence of the temperature due to the destruction of hydrogen bonds and the enhancement of hydrophobic interaction in aqueous solution. The processes of reversible swelling or shrinking upon temperature change are demonstrated for polymer networks.

No abstract

Novel thermo-sensitive linear and crosslinked copolymers of vinyl ether of ethylene-glycol and vinyl butyl ether have been synthesized by gamma-irradiation copolymerization. The effect of comonomer hydrophobicity, neutral salts addition and nature of cations and anions on the position of lower critical soluble temperature of water-soluble copolymers and swelling-deswelling behavior of networks is demonstrated. The combination of thermosensitivity and pH sensitivity of hydrogels are realized in the case of crosslinked terpolymers. Copyright

The complex formation reaction of poly(viny1 ethers) of ethylene glycol (l), poly(viny1 ether) of diethylene glycol (2), copolymers of vinyl ether of ethylene glycol and vinyl butyl ether (3 a-3 c) with poly(acry1ic acid) (PAA) and poly(methacry1ic acid) (PMAA) was studied by conductimetric, viscometric and spectroturbidimetric methods in aqueous solution. It is shown that 1 and 2 do not form polycomplexes with PAA. While an introduction of hydrophobic vinyl butyl ether fragments into the structure of 1 enhances the complexation processes with respect to poly(carboxy1ic acids), the composition of the polycomplexes is independent of the mixing order of interacting components, temperature and composition of the copolymers. An addition of organic solvents to the aqueous solution of the polycomplexes leads to the cooperative destruction of polycomplex particles. An analysis of IR spectra of the polycomplex films shows the existence of -COOH dimers, hydrogen bonds between hydroxyl groups and carboxylic groups as well as ester bonds.

Novel thermo‐sensitive linear and crosslinked copolymers of vinyl ether of ethylene‐glycol and vinyl butyl ether have been synthesized by gamma‐irradiation copolymerization. The effect of comonomer hydrophobicity, neutral salts addition and nature of cations and anions on the position of lower critical soluble temperature of water‐soluble copolymers and swelling‐deswelling behavior of networks is demonstrated. The combination of thermosensitivity and pH sensitivity of hydrogels are realized in the case of crosslinked terpolymers. Copyright © 1999 John Wiley & Sons, Ltd.