Story of a Material, or 2-Hydroxyethyl Methacrylate: Monomer, Polymer, Properties and Uses

Abstract

Since the discovery of the hydrophilic swollen gels prepared by the radical polymerization of 2-hydroxyethyl methacrylate by prof. O. Wichterle and his group there has been a great effort to investigate this polymer. It was due not only to the use of poly(2-hydroxyethyl methacrylate) (PHEMA) for hydrogel contact lenses but also to its interesting physical and chemical properties. It is characterized by its ability to swell in both hydrophilic and hydrophobic media and a very good compatibility with living tissues. Even after being swollen in aqueous environment, PHEMA retains a sufficient mechanical strength, flexibility and stability over time. The material has therefore been used in various applications. In addition to ophthalmology, it was investigated for implants or polymer systems for controlled drug delivery. Less known is its use in sorbents or monoliths for chromatographic column packing. However, it remains an object of great scientific interest, as evidenced annually by the number of publications with this key word. At the same time, it represents an important model polymer in both the scientific research of synthetic hydrogels and biomedical applications including tissue engineering. It is the aim of this article to give a clear overview of the history, structure and properties of this unique monomer, its polymers and applications, based on the findings of literature and the results of our own experiments.