Hello dear it is possible, but there are some aspect important for it:

1) Particle size of the wood have to have smallest

2) The proportion of PU, have to be higher than that of the wood.

3) The dispersion of the wood into PU have to be so good

yes, when you reduce the air humidity (very low only any %RH (dried air)

Peter Niemz

Its polymer matrix is water-based or 100% solids?

Sir,100% solid (moisture curing polyurethane)

To reduce/ eliminate foaming in 1 K PUR based pre-polymer,what type of additive are used?

Baylith Zeolites, http://www.abcolby.com

Yes, it is possible using a zeolite, with A4 molecular sieve.