Nanocomposites Based on Multicomponent Polymer Matrices and Nanofiller Densil for Biomedical Application

Nanocomposites based on polyurethane/poly(2-hydroxyethyl methacrylate) multicomponent polymer matrix and nanofiller densil were created, and structure, thermodynamic miscibility and dynamic mechanical and physicomechanical properties have been investigated. The free energy of interaction values between the polymer components and nanofiller, calculated based on vapor sorption results, was negative in case of matrix semi-IPN with 17 % of PHEMA, and it was positive in case of matrix semi-IPN with 37 % of PHEMA as the result of competition between two processes: the formation of the dense layers of polymers on the surface of the nanofiller and the formation of interfacial layers with the excessive free volume in the nanocomposites. The structural features of the nanocomposites polyurethane–densil have shown that at minimum nanofiller content (1 %), it is almost uniformly distributed in the polyurethane matrix. With increasing nanofiller content in the matrix, aggregation occurs in the form of mass–fractal structures, typical for the native nanofiller. The investigation of dynamic mechanical and physical–mechanical properties of composites demonstrated that optimum physical and mechanical properties have the systems with concentration of nanofiller which is near its respective threshold for aggregation (i.e., 1 % for the nanocomposites with polyurethane matrix, 3 % for those with semi-IPN 17 matrix, and 5 % for those with semi-IPN 37 matrix).