Investigations of polyurethane matrices for solid-state laser active elements showed that comparison of chain mobility and permeability for low molecular substances of polyurethanes based on glycol and diisocyanate components of various structures allows predict their radiation resistance and choose optimal chemical composition of polyurethane. The correlation was shown of polyurethane dynamic properties with values of their elastic modulus and laser damage threshold under pulsed laser irradiation as well as the weak influence of phenalenone dyes introduction on the above characteristics.