Does Polyester resin + catalyst react with uncured polyurethane foam?

[mess]

TL;DR

I used some polyurethane spray foam in a cold environment, it did not fully cure and i put polyester resin ontop of it. It never cured.

I left it on for about 3 weeks, most of the time it was in below curing temperature, sometimes below freezing, but i gave it about 15 hours of 20c+ to try to cure it. It never did, and still smelt really bad. I decided to rip off the resin that had hardened. Underneath it, the polyurethane foam looked strange, and smelled very strong of uncured resin. I dug deep into the foam, about 15cm, and the foam seemed different wherever the resin had been on top, as if it absorbed part of the resin and only partially cured.

The resin i used, i mixed with cabosil and chopped fiberglass to give it a peanut butter consistency, so i am not sure how it could have gone that deep into the foam.

Was there a reaction between the two uncured compounds? If so, is the off gassing more toxic then either of the original two compounds could produce?

 

[Borek]

You would need someone versed in resins, but even then the answer would be largely "it depends". There is no one polyurethane foam, there is no one polyester resin. There are many and they differ in formulations, so I wouldn't expect a single answer to "what happened when I mixed a random foam with a random resin?".