Effect of chain extenders on the structure and properties of polyurethanes

The objective of this work was to determine the influence of different chain extenders (CEs) on the structures and properties of polyurethanes (PUs) materials. CEs increase phase separation in thermoplastic and thermoset PUs with significantly impact the density of hydrogen bonds (Xb). In general, the higher the miscibility of CEs with hard and soft domains, the lower tendency to phase separation and the appearance of a single glass transition temperature (Tg). In addition, the miscibility of CEs and side groups tend to form polymers with no long-range order. The results shown in this work can contribute to obtaining polyurethane materials with tunable structures. (author)