Structure–properties investigations in hydrophilic nanocomposites based on polyurethane/poly(2–hydroxyethyl methacrylate) semi‐interpenetrating polymer networks and nanofiller densil for biomedical application

Abstract

Nanocomposites based on sequential semi-interpenetrating polymer networks (semi-IPNs) of crosslinked polyurethane and linear poly(2-hydroxyethyl methacrylate) filled with 1-15 wt % of nanofiller densil were prepared and investigated. Nanofiller densil used in an attempt to control the microphase separation of the polymer matrix by polymer-filler interactions. The morphology (SAXS, AFM), mechanical properties (stress-strain), thermal transitions (DSC) and polymer dynamics (DRS, TSDC) of the nanocomposites were investigated. Special attention has been paid to the raising of the hydration properties and the dynamics of water molecules in the nanocomposites in the perspective of biomedical applications. Nanoparticles were found to aggregate partially for higher than 3 and 5 wt % filler loading in semi-IPNs with 17 and 37 wt % PHEMA, respectively. The results show that the good hydration properties of the semi-IPN matrix are preserved in the nanocomposites, which in combination with results of thermal and dielectric techniques revealed also the existence of polymer-polymer and polymer-filler interactions. These interactions results also in the improvement of physical and mechanical properties of the nanocomposites in compare with the neat matrix. The improvement of mechanical properties in combination with hydrophilicity and biocompatibility of nanocomposites are promising for use these materials for biomedical application namely as surgical films for wound treatment and as material for producing the medical devises.

Effects of Hydration/Dehydration on Interfacial Polymer Fraction and Dynamics in Nanocomposites Based on Metal–Oxides and Physically Adsorbed Polymer

“…Effects of PNCs hydration on polymer dynamics have been mainly followed via modifications in bulk-like segmental mobility (calorimetric glass transition 35,36 or dynamic α relaxation 8 ) and in dynamics of secondary processes (local relaxations of polymer side groups). 4,8,20,37 During recent years, in a significant number of papers in the literature on PNCs, mainly based on hydrophilic nanoparticles, there has been recorded a distinct dielectric relaxation mechanism (α int relaxation) of interfacial polymer next to that of the bulk (for rubbery 30,38−41 and for thermoplastic 42−44 polymers) via dielectric spectroscopy. More recently, Sokolov and co-workers intensively studied α int along with parameters that affect the structure and dynamics of the interfacial polymer in PNCs, 45−47 main results and involved methodological approaches being summarized in a recent review article by the same group.…”

“…and either hydrophobic or hydrophilic polymers, it has been proposed that water at the interfaces between nanoinclusions and macromolecules results in an interfacial, Maxwell–Wagner–Sillars (MWS) like relaxation ,, or a new, distinct, relaxation process activated within the water clusters. ,,, We should report that Boehning et al recorded in polymer/clay PNCs an additional water-related relaxation mechanism that exhibits unusual temperature dependence. Effects of PNCs hydration on polymer dynamics have been mainly followed via modifications in bulk-like segmental mobility (calorimetric glass transition , or dynamic α relaxation) and in dynamics of secondary processes (local relaxations of polymer side groups). ,,, During recent years, in a significant number of papers in the literature on PNCs, mainly based on hydrophilic nanoparticles, there has been recorded a distinct dielectric relaxation mechanism (α int relaxation) of interfacial polymer next to that of the bulk (for rubbery ,− and for thermoplastic − polymers) via dielectric spectroscopy. More recently, Sokolov and co-workers intensively studied α int along with parameters that affect the structure and dynamics of the interfacial polymer in PNCs, − main results and involved methodological approaches being summarized in a recent review article by the same group .…”

Thermal Energy Storage Capability of Polyurethane Foams Incorporated with Microencapsulated Phase Change Material

“…Polyurethane (PU) foams, as an easy‐to‐form polymer material, possess excellent characteristics, such as porosity, low density, aging resistance, organic solvent resistance, and outstanding thermal insulation. These foams are widely applied in construction, packaging, and other industrial fields for thermal insulation as ultimate energy savers To overcome the inconsistency between energy supply and demand the thermal energy storage property of PU foams has been investigated in building heating/cooling systems ,.…”