A substantially biobased prepolymer mixture including 31.80 to 67.95 percent biogenic carbon content by weight, wherein the mixture is a combination of: an isocyanate; and a cleaned biobased polyoxyalkylene glycol polyol, wherein the cleaned biobased polyoxyalkylene glycol polyol is completely primary hydroxyl-tipped or primary hydroxyl end-grouped, further wherein said cleaned biobased polyoxyalkylene glycol polyol is polymerized from 100% biobased ethylene oxide, further wherein the cleaned biobased polyoxyalkylene glycol polyol comprises less than 15 ppm sodium and potassium metals, and further wherein the cleaned biobased polyoxyalkylene glycol polyol comprises less than 0.5% water by weight.