Surface recrystallization of polyethylene extended-chain crystals.
Rough fracture surfaces of extended-chain polyethylene crystals become unstable at temperatures below the bulk melting point. There is no way for the extended chains, which are up to 20,000 methylene units long, to change position without collapse. As a result, the rough surfaces smooth out on heating by covering themselves with oriented folded-chain lamellae.
Wunderlich
B
B
Melillo
L
L