Two component hydrogels. Theoretical considerations and experiments

This is the authors' abstract. We don't add key points for this paper.

The preparation of defined one and two component networks by simultaneous copolymerization and crosslinking is described as well as the calculation of the crosslink density and the number of elastically active chains from copolymerization data. The two component networks built up in this manner consist of a polymer backbone formed by one polymer component, which is crosslinked by bridges of another polymer of varying length. Such networks in the swollen state, using water as solvent, can be treated within the framework of existing swelling and mechanical theories. The information derived from copolymerization data is compared critically with those derived from equilibrium swelling and deformation behaviour. In addition, NMR‐spin‐lattice relaxation data are discussed, which give some insight into the relative affinity of each polymer for the solvent. Finally an expression for the activity of the solvent in the network phase as result of swelling of a two component network is given. The crosslinked graft copolymers discussed in this paper consist of poly‐(N‐vinyl‐2‐pyrrolidone) as the backbone and poly(ethylene glycol) as the interconnecting bridge. Conclusions derived from the two component hydrogel studies should be relevant for non‐hydrophilic two component networks too.