Crystal-amorphous polymer interface studied by neutron and X-ray scattering on labeled binary ultralong alkanes

Semicrystalline polymers such as polyethylene, polypropylene, and nylon form thin (100-500 A) crystalline lamellae separated by an amorphous layer containing chain folds, end, and intercrystalline ties. The long-standing controversy over the nature of the amorphous layer and, particularly, of the crystal-amorphous interface is partly due to a lack of experimental techniques for probing the interface directly. This paper shows how specially synthesized selectively deuterated model compounds studied by a combination of small-angle neutron (SANS) and x-ray scattering can provide the relevant experimental information with considerable detail.