I've imported a fair-few objects from Blender into Poser. You might want to save out your obj as a pp2 or cr2, save all your textures in your folder under runtime:textures and then open either the pp2 or cr2 in NotePad++ or something of that quality and check the paths. The materials will be there: all you might have to do is fix the paths.

However, that's only a small part of getting good renders in Poser, the bigger part of which is sorting out your materials in the material room (ie, nodes).

Monterey/Mint21.x/Win10 - Blender3.x - PP11.3(cm) - Musescore3.6.2

Wir sind gewohnt, daß die Menschen verhöhnen was sie nicht verstehen
[it is clear that humans have contempt for that which they do not understand] 

Metaphor of Chooks