In situ copper-ion catalyzed synthesis of copper containing poly(isocyanurate-urea) xerogels with antibacterial activity and biocompatibility for biomedical applications

Abstract

In this study, we report the synthesis of copper ion containing polyisocyanurate-urea xerogels (Cu-PIU) by reaction of organic monomers containing isocyanate functional groups catalyzed by copper chloride. Wet gels were dried under ambient temperature and pressure conditions to yield Cu-PIU xerogels which is a simple and economic process. The obtained xerogels were found to have bulk and skeletal densities of 1.2 and 1.4 g/cc respectively. The metal ions were found to catalyze the reaction of polyisocyanurate-urea by initiating the trimerization of isocyanate to isocyanurate; additionally, the water present in the hydrated metal salts was found to form urea linkages by reacting with the isocyanate functional groups. The copper containing polyisocyanurate-urea xerogels and coatings were found to exert excellent antibacterial properties on both ‘Staphylococcus Aureus’ (Gram positive) and ‘Escherichia Coli’ (Gram negative) bacteria through the zone of inhibition method. Moreover, the prepared polymer composites and metal-ion doped polymeric xerogels exhibited good bioadhesion and bio-compatibility towards MG63 cells which indicates the non-toxic nature of the materials and hence they can be used in the biomedical field.