2H-NMR and 13C-NMR Study of the Hydration Behavior of Poly(2-methoxyethyl acrylate), Poly(2-hydroxyethyl methacrylate) and Poly(tetrahydrofurfuryl acrylate) in Relation to Their Blood Compatibility as Biomaterials

We recorded 2H-NMR spectra of (deuterated) water in the presence of poly(2-methoxyethyl acrylate) (PMEA), poly(2-hydroxyethyl methacrylate) (PHMEA) and poly(tetrahydrofurfuryl acrylate) (PTHFA). The observed 2H-NMR peak intensities varied substantially with water content and temperature, depending upon either strong binding to polymer surface or suppressed peaks due to freezing. Indeed, 2H-NMR signals in the presence of PHEMA were strongly dependent upon its water content, while those of hydrated PMEA and PTHFA remained unchanged even at −30°C and −20°C. The latter were considerably broadened at −50°C and −30°C, respectively, due to freezing water from the super-cooled state. As a result, the states of the water molecules in PMEA and PTHFA can be classified into three types; free, freezing bound and non-freezing water molecules. The states of the water in PHEMA depend on the water content, and the water can be classified into two types, free and non-freezing water, which exhibit rapid fluctuation and rest...