Since you are just doing the CB thing and you are not a Ham; then there is no real point in doing a real flagpole antenna that needs radials.
If you do use PVC pipe over the Imax; then just be sure that there is no metal flagpole parts on it that my de-tune the Imax. Otherwise, it should work OK.
If you do use PVC pipe over the Imax; then just be sure that there is no metal flagpole parts on it that my de-tune the Imax. Otherwise, it should work OK.