Assessment of interfacial interactions between starch and non-isocyanate polyurethanes in their hybrids.

Manufacturing of multifunctional materials through blending is a promising route for improving performance of biopolymers including starch. Non-isocyanate polyurethanes (NIPUs) are an emerging group of green materials. Understanding the mechanism of interaction between starch and NIPU not only highlights underlying chemistry but also offers an opportunity to tailor the properties and functions of starch-NIPU hybrids. We investigated the interfacial interactions between starch and NIPU to pave the way towards development of high-performance green materials. Multiple analyses revealed that NIPU interacted effectively with starch chains via intermolecular hydrogen bonds. We showed that NIPU domains can efficiently interact with the small portion of starch skeleton at interfacial region and they are only moderately miscible. Incorporation of either component above certain ratio resulted in a phase separation. This work contributes towards understanding of interfacial chemistry between starch and NIPUs and enables tailoring the interface for facile engineering of starch-NIPU hybrids.