Structure-Property Relationships of Thermoplastic Polyurethanes from Bio-Based C18 Polyester Polyols

摘要

A series of C18 polyester polyols with diverse structures were prepared through poly condensation of Elevance Inherent~(TM) C18 Diacid with various diol comonomers. Thermal properties of C18 polyols highly depend on constituent diol structures: linear aliphatic diols yield polyols with high melting temperatures which may be useful in hot-melt adhesives and shape-memory polyurethanes (PUs), while branched aliphatic and ether-containing diols lead to liquid/semi-solid polyols suitable for PU coatings and elastomers. Compared with high-performance specialty polycarbonate (PC) polyols, C18 polyols exhibited >30-fold lower viscosities at relevant processing temperatures which enable higher solids and low/zero VOC PU formulations. Benefiting from the completely biorenewable C18 Diacid, the bio-based carbon content of C18 polyols are generally high (61-100%). Structure-property relationships of thermoplastic PUs (TPUs) based on C18 polyols were studied benchmarking against reference TPUs based on traditional polyester, polyether, and PC polyols. C18 TPUs, especially the crystalline ones, showed high ultimate tensile strength, tear strength, compression set and good resilience while preserving impressive solvent resistance. In contrast to TPUs from conventional polyester polyols, C18 TPUs displayed excellent hydrolytic stability under harsh conditions of elevated temperature and high humidity. Thus, C18 polyols are a promising new class of bio-based high-performance building blocks well-suited for demanding PU applications all while advancing end-user sustainability initiatives.