Radiation-induced synthesis of thermo-sensitive, gradient hydrogels based on 2-(2-methoxyethoxy)ethyl methacrylate

• Thermo-sensitive hydrogels with gradient of cross-link density.
• Analysis of parameters describing network formation.
• Synthesis of hydrogels with various morphologies depending on post-irradiation procedure.

The gradient (“transient”) systems are required for many biomedical applications, especially if the materials with different properties are to be joined without strong internal stresses. In this paper one step, radiation-induced synthesis of thermo-responsive hydrogels based on 2-(2-methoxyethoxy)ethyl methacrylate with gradient in crosslink density, has been presented. The influence of the monomer composition and synthesis procedure (irradiation dose and conditioning temperature) on the general properties of prepared gels has been discussed. It has been found that the properties of particular sections of the gel sample do not result from the differences in chemical structure, but from significantly different morphology. The explanation of the mechanism leading to gradient behavior of obtained gels has been proposed. The chemical structure of obtained products and morphology of synthesized hydrogels as well as general properties of products have been analyzed.