I've always thought of duranium to be something like durasteel from star wars: it's like steel, but better. Using star wars again, neutronium I've always assumed to be a very dense, strong material making it impractical for armor, but good for other stuff like shipyards. Uridium I've assumed to be very reactive to radiation, making it ideal for detection systems. I guess boronide functions as some sort of super-duper-über conductor, making it ideal for power systems. Corbomite I've thought of as being absorbent to most radiation, allowing to absorb large amounts of energy for shields or conceal the energy signature of a vessel for cloaking devices. Gallicite probably has an extremely high specific heat capacity, making it a practical material for engines that generate power equivalent to thousands of chemical rockets. Corundium most likely works as a focus for various types of energy, and vendarite is probably a lightweight, strong material like titanium. Sorium is some sort of highly energetic material, probably the most physics defying one as it appears to allow the function of jump engines. Tritaniunm I assume to be a highly volatile material, capable of releasing energy Over a much smaller period of time than sorium, thus leading to large booms. Mercassium is probably some sort magnet-like substance, being used to accelerate other materials for research purposes in labs, or "grab" them for tractor beams, and extracting them from the air for life support.
