What chemicals are needed to make the polyurethane paste that is used in the joints of buildings to make them water proof, and what process is used to get the mixture to a state that it can be used on building?

Large government agencies like the state highway admin. I worked for have their own testing and evaluation divisions to test and/or certify materials being used in a project. Some also have new product committees, members of which consider the use of state of the art materials that are coming on the market but not necessarily already covered in their specifications. That might help with your process question but I don't know about the chemicals side of your question.