Incorporation of Honey-Based Phenolic Acids Into Shape Memory Polymer Foams for Use as Antimicrobial Hemostat

Polyurethane shape memory polymer (SMP) foams are ultra-low density, “smart” materials that transition between a primary and secondary shape when exposed to a thermal stimulus. This material has the potential to be used in a new application as a hemostatic wound dressing. Honey-based phenolic acids are a class of naturally occurring antimicrobial substances produced by bees to protect their hives from harmful microbes in the environment. To tune the properties of SMP foams to best serve the proposed application, these honey-based phenolic acids will be incorporated into the polymer backbone to impart antimicrobial properties to the foams. An esterification reaction involving a phenolic acid and N,N,N,N’-tetrakis(2-hydroxypropyl) ethylene diamine (HPED) is carried out to produce a modified HPED molecule where one of the alcohol groups is replaced by the phenolic acid. SMP foams are then synthesized using hexamethylene diisocyanate (HDI), HPED, and varied amounts of triethanolamine (TEA) and the modified HPED-phenolic acid monomer. The resultant foams are characterized to determine their density, pore size, glass transition temperature (Tg), rate of thermal actuation, and antimicrobial properties