Development of waterborne polyurethane-ureas added with plant extracts: Study of different incorporation routes and their influence on particle size, thermal, mechanical and antibacterial properties
Polyurethane-ureas are a versatile family of polymers which can be employed in a wide range of applications. Among them, waterborne polyurethane-urea (WBPUU) dispersions are gaining relevance in the field of environmentally-friendly products since their productive process adopts green synthesis routes, avoiding the use of organic solvents. Furthermore, their waterborne character can be exploited to incorporate several water compatible ingredients able to confer functional properties to the final materials. Among them, plant extracts, which are known to have relevant bioactivities, can be viewed as interesting candidates. Therefore, in this work, two extracts known to present antimicrobial activity (Melissa officinalis L. and Salvia officinalis L.) were obtained by the infusion method and incorporated into the WBPUU (1, 3 and 5 wt%) following different incorporation routes comprising its adding during different phases of the productive process (post-, in-situ and pre- methods). Thereafter films were prepared by solvent-casting and characterized from the viewpoint of physicochemical, thermal, mechanical, thermomechanical and antibacterial properties and morphologically. The studied incorporation routes resulted in different intercalation mechanisms that varied from extract positioned among the polyurethane-urea nanoparticles (post-method) to extract partially embedded inside them (in-situ and pre-methods), which produced stiffening or flexibilizing effects in the produced films, enhancing in general the antimicrobial characteristics of films after 4 days of incubation comparing with base WBPUU, especially when the extract is embedded.Financial support from the Basque Government (IT-776-13), the Spanish Ministry of Economy and Competitiveness (MINECO) (MAT2016-76294-R), POCI-01-0145-FEDER-006984 (LA LSRE-LCM) funded by ERDF through POCI-COMPETE2020 and FCT and NORTE-01-0145-FEDER-000006, funded by NORTE 2020, under PT2020 through ERDF is gratefully acknowledged. We also wish to acknowledge the “Macrobehaviour- Mesostructure-Nanotechnology” SGIker units from the University of the Basque Country, for their technical support. A.S-E thanks the University of the Basque Country for Ph.D. grant (PIF/UPV/12/201).Financial support from the Basque Government (IT-776-13), the
Spanish Ministry of Economy and Competitiveness (MINECO)
(MAT2016-76294-R), POCI-01-0145-FEDER-006984 (LA LSRE-LCM)
funded by ERDF through POCI-COMPETE2020 and FCT and NORTE-
01-0145-FEDER-000006, funded by NORTE 2020, under PT2020
through ERDF is gratefully acknowledged. We also wish to acknowledge
the “Macrobehaviour- Mesostructure-Nanotechnology” SGIker
units from the University of the Basque Country, for their technical
support. A.S-E thanks the University of the Basque Country for Ph.D.
grant (PIF/UPV/12/201).info:eu-repo/semantics/publishedVersio