Dear Michael Bay, hydrolytic hydrolysis is the problem. To overcome this problem, superhydrophobic surfaces are the most followed solution. Please check the following documents. My Regards

https://www.researchgate.net/publication/256922981_Structural_engineering_of_polyurethane_coatings_for_high_performance_applications

https://www.sciencedirect.com/topics/engineering/hydrolytic-stability

https://doi.org/10.1021/ma500904d

These 12 pages of the pdf file, written by the professional engineer Kenneth B. Tator, will be helpful for your research. The urethane linkage which combines ester & amide groups, the cabonate linkage -O-(C=O)-O-, and the ester linkage, -(C=O)-O-R, in the acrylates show resistance to acids usually and that is one reason why the polurethanes are used in protective coatings. Applying RT conditions adds to stability of coatings but long exposure to strong acids for 30 days is a destabilizing factor. Anyhow, your research is quite interesting wishing you success.

If you substitute the polyurethane linkage with a polyurea linkage (use amines instead of polyols) you will get a way better chemical (and mechanical) resistance of your products.

Hi;

Chemical resistance is a property that is defined by the reaction of a material to short or prolonged contact with a chemical. The stronger a material reacts upon contact, the more damage it will suffer from the chemical agent in question. Conversely, a weak reaction will cause less damage, allowing the material to retain its initial.

Please see the link below:

https://www.pcimag.com/articles/104688-development-of-a-chemical-resistant-two-component-polyurethane-coating-system

With my best regards