A functional film includes a transition layer having a first constituent and a second constituent having gradual content gradients according to a thickness of the functional film. The first compartment includes a base web having a formed portion and a flat portion, a lidding material joined to the flat portion and a frangible seal positioned between the base web and the lidding material. Preferred polymers include polycarbonates, polysulfonyl esters, polycarbonate sulfones, and mixtures thereof.