<p>Waterborne polyurethane is an attractive material used to formulate solvent-free hot-melt adhesives (HMAs). In this study, a novel poly (propylene carbonate)-based waterborne polyurethane (PPC-WPU) for hot melt adhesives was synthesized from poly (propylene carbonate) glycol (PPC), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI) and dimethylol propionic acid (DMPA). This article explores the effects of the initial R value, DMPA content, and HDI/IPDI ratio on adhesive performance. The influences of all these research parameters on the activation temperature, glass transition temperature (Tg), mechanical properties and adhesion properties of the resultant PPC-HMAs were analyzed and discussed via FTIR, SEM, XPS, XRD, DSC, tensile tests and T-peel strength tests. These characterizations confirmed the successful preparation of PPC-WPU with a well-defined chemical structure, dense and uniform micro-morphology, and low crystallinity. The results show that the R value and DMPA content affect the particle size and Zeta potential of the emulsion, and further influence the T-peel strength, activation temperature, glass transition temperature (Tg) and mechanical strength of the resultant films.When the R value is 1.65 and DMPA content is 4.7 wt%, the T-peel strength reaches its maximum. The activation temperature and Tg increase as the R value rises. DSC analysis revealed that the activation temperature and Tg decrease linearly with an increase in the HDI/IPDI molar ratio. This work provides a feasible direction for the application of PPC-WPU as high-performance waterborne hot melt adhesives.</p>