Phase change materials (PCMs) are broadly adopted in buildings and other applications because of their excellent energy storage effect. However, aqueous phase change materials are less reported. In this article, a waterborne polyurethane with phase change functionality (WPU-A) was prepared and modified with trimethylolpropane (TMP) and hydroxyethyl methacrylate (HEMA); and then allowed to cross-link with a waterborne polyurethane (WPU-B) with PTMG as the soft segment to produce a multicross-linked, two-component phase-change waterborne polyurethane (PCMWPU). It is discussed that the phase change properties, hydrophobicity, and tensile strength of PCMWPU films were improved with the addition of WPU-A. The data show that the highest enthalpy of PCMWPU films can reach 90.3 J/g, the static water contact angle can reach 108.3°, and the highest tensile strength is 27.4 MPa. In addition, PCMWPU film has shape stability at higher temperatures (100 °C), no liquid leakage, good thermal stability, and shows some reversible light transmission phenomenon, which has a wide range of application prospects.

Preparation and Properties of Acrylic Acid-Modified Multicross-Linked Two-Component Waterborne Phase-Change Polyurethane