Biobased, Biodegradable, and Water-Soluble Amine-Functionalized Non-Isocyanate Polyurethanes for Potential Home Care Application

Abstract

Non-isocyanate polyurethanes (NIPUs) synthesized using bis–/poly(cyclic carbonate) and di-/polyamine monomers provide a safer alternative to conventional polyurethanes (PUs) produced from highly toxic di-/polyisocyanates and di-/polyols. Water-based NIPUs could potentially substitute waterborne PUs, particularly, in applications where the presence of minute amounts of isocyanate impurity in the final PU product might cause severe consequences. Nevertheless, direct syntheses of water-soluble NIPUs are uncommon. Herein, we report a single-step synthesis of water-soluble and bio-derived linear amine-NIPUs by the polyaddition reaction of succinic bis(cyclic carbonate) (SuBCC) with different commercial polyamines. These amine-NIPUs contain secondary (−NH−) or tertiary (−NR−) amine groups in their main chain imparting good water solubility/dispersibility. Consequently, the water-soluble amine-NIPUs were evaluated for their function as anti-soil/dirt redepositioning agents, one of the key ingredients present in laundry detergents used in home care applications. It is demonstrated that amine-NIPUs in this study are effective in retaining >90% whiteness (L*) of cotton and polyester cloths after model dirt deposition and wash cycle. Remarkably, these polymers were noncytotoxic when tested on human keratinocyte HaCaT cells and non-skin irritants by in vitro skin irritation assay using reconstructed human epidermis, which emphasizes their suitability for home care applications further. The amine-NIPUs were also found to degrade slowly (65% in 32 days) under hydrolytic conditions similar to that of seawater (pH 8.4 at 23 °C) and were biodegradable in activated sludge (up to 66% in 28 days), as determined by Zahn Wellens OECD-302-B assay. This work may pave the way toward the development and utilization of green, sustainable, and biodegradable NIPUs in home care and other applications, replacing the current toxic, nondegradable, and petroleum-based ingredients.