Biocompatible nanocomposites based on semi-interpenetrating polymer networks and nanosilica modified by bioactive amino acid tryptophan: Morphology, dynamics and properties

Abstract

The nanocomposites based on polyurethane and poly(2-hydroxyethyl methacrylate) (PU-PHEMA) semi-IPN matrices with 17 or 37wt.% PHEMA, containing from 3 to 15wt.% nanosilica (NS), were synthesized aiming at the biomedical applications. NS surface was modified using the mechanosorptive method, with formation of basically monomolecular layer of biologically active substance – amino acid tryptophan. The AFM analysis of morphology of the nanocomposites and the complex DSC-TSDC-DMA-CRS analysis of their thermal, relaxation and elastic properties over the broad temperature range, from −150 to 200°C, were performed. Satisfactory nanofiller dispersion and the pronounced changes in matrix morphology were observed at 17wt.% PHEMA in the matrix, whereas nanofiller submicro- and microaggregates prevailed in the nanocomposites with 37wt.% PHEMA. As a result, just in the first case the most substantial “constrained dynamics” effect (e.g., increasing Tg by 20–30°C) was observed in the nanocomposites.