| abstract |
1. A copolymer containing: - monomer units A having a cyano-containing side group in which the cyano group is not directly attached to the main chain of the copolymer; - monomer units B having a film-forming side group; - monomer units C having a side chain containing poly (ethylene glycol) ), poly (propylene glycol) and / or random poly (ethylene glycol-propylene glycol), wherein said side chain is attached to the main chain of the copolymer via an amide, carbamate, ester or urea linker; and optionally monomer units D having at least one functional group capable of undergoing a crosslinking reaction as a result of cationic polymerization. 2. The copolymer according to claim 1, described by the formula Formula 1, wherein: - a, c, and d are molar fractions ranging from about 0.01 to about 0.90; - b and e are molar fractions ranging from about 0 up to about 0.90; - A1 is the monomer units of A; - A2 is the monomer units of A or monomer units of B; - A3 is the monomer units of C; - A4 is the monomer units of B; and - A5 is monomer units B or monomer units D, where monomer units A in A1 and A2 are different from each other, and where monomer units B in A2, A4 and A5 are different. 3. The copolymer according to claim 1, where the monomer units A are described by the formula where: - R represents hydrogen, methyl or ethyl; - R is absent or represents from one to four alkyl or alkyloxy substituents, while alkyl and alkyloxy substituents are optional� |