Investigation of Phase Separation and Morphology of Organic-Inorganic Interpenetrating Polymer Networks

The paper investigates the process of phase separation and morphology of organic-inorganic interpenetrating polymer networks (OI IPNs) based on the cross-linked polyurethane (PU), poly(hydroxyethyl methacrylate) (PHEMA) and poly(titanium oxide) (–TiO₂–)_n obtained by solgel method in the presence of poly(oxypropylene glycol) (POPG) at various molar ratio of titanium (IV) isopropoxide (Ti(OPrⁱ)₄) and water. It has been established that the phase separation in OI IPNs depends on the kinetics of PHEMA-component formation and it occurs through the mechanism of the spinodal decomposition. It has been shown that by varying the ratio of IPNs components, content of inorganic component and Ti(OPrⁱ)₄/H₂O molar ratio it is possible to control the phase separation process and obtain OI IPNs with a different phase structure.