A study of melting of low density polyethylene by in situ WAXD

Analysis of low density polyethylene using in situ wide-angle X-ray diffraction shows that the melting process takes place over a broad temperature range with continuous destruction of lamellar laterals. This process exhibits decreasing rate as the temperature increases, indicating that in general each lamellae has less order in outer regions than in central ones. The shifts in angular position of the amorphous halo as a function of the temperature show that the amorphous phase in a semicrystalline sample is less disordered compared to that in an overall melted sample. As the temperature increases the unit cell parameter a increases, generating a crystalline phase density reduction.