SAXS investigation of the structural features of relaxed poly(vinylidene fluoride)

- Poly(vinylidene fluoride) (PVDF) relaxed samples were analyzed by Small Angle X-ray Scattering (SAXS). The long period (Lp) and several structural parameters were calculated using Bragg's Law and the linear correlation function γ(r) methods. By the last method, it was observed that Lp decreases as relaxation temperature rises. The amorphous thickness (La) of relaxed samples got lower in comparison with non relaxed sample, even for relaxation at 23°C, suggesting that chain recoil took place in amorphous region. Both lamellar (Lc) and intermediate phase (IT) thicknesses rose as relaxation temperature increased, indicating the occurrence of thermal crystallization and a partial ordering of intrafibrilar amorphous chains. (author)