fungicide for 2K polyurethane coating in marine environment 1

[clandestinho]

Hello everyone,
I am looking for an efficient fungicide for a 2K polyurethane coating (polycarbonate based PUD and HDI). This coating will be used in a marine environment on a substrate that's semi-porous. The problem is mainly with black mold thriving extremely well on this hard but somewhat open surface.
I have tried several products but so far I haven't found anything that black mold can't live on. This coating is supposed to have a 5-10 year life so I need an additive that's efficient long term.

I would like to hear if someone can suggest a particular chemistry to try?

Many thanks!

 

[TugboatEng]

You can compound your own.

https://www.sciencedirect.com/science/article/pii/S2238785423009377

There are commercially available PU products.

https://gulfcoastpaint.com/product/ct-377-gulf-thane-antimicrobial-hb-gloss-polyurethane/

Is there a reason you need polyurethane?