Self-nucleation and enhanced nucleation of polyvinylidene fluoride (α-phase)

The nucleation phenomena of poly(vinylidene fluoride) in its α-phase (α-PVDF) are investigated. Self-seeding first investigated helps establish a so-called ‘efficiency scale’, which in turn helps rate the nucleation induced by crystalline additives, and notably PTFE. The thermal and nucleation behavior of α-PVDF is significantly dependent on its microstructure. Samples with higher head-to-head inversions display a significant ‘memory effect’: their initial spherulitic morphology is maintained in successive recrystallizations. The nucleation density can be increased by addition of nucleating agents: PTFE or flavanthrone. The nuclei densities reached are, however, nearly two orders of magnitude lower than for isotactic polypropylene. These results serve as a basis for a companion investigation of the nucleation of blends of PVDF and polyacrylic polymers, the structural characteristics and properties of which can be significantly modified by enhancing nucleation.