Aqueous prepolymer dispersions are provided, as are methods for making aqueous prepolymer dispersions. For example, an aqueous polyurethane prepolymer dispersion may be prepared by a process. The process may include contacting a soybean oil polyester polyol and an isocyanate reactive monomer together in a first mixture. The isocyanate reactive monomer may be functionalized with a tertiary amine salt of an isocyanate-unreactive organic acid. The process may include contacting the first mixture with a diisocyanate to form a neutralized polyurethane prepolymer. The process may include contacting the neutralized polyurethane prepolymer with water to form the aqueous polyurethane prepolymer dispersion.