Complex sentence: Slowing this tendency of objects to self-destruct requires an understanding of how materials interact: the intrinsic qualities of the materials, but also the way that they affect and are affected by other materials that they come into contact with.
Split into simpler sentences: Slowing this tendency of objects to self-destruct requires an understanding of how materials interact. This includes not just the intrinsic qualities of the materials, but also the way that they affect and are affected by the other materials that they come into contact with.