PVDF
Polyvinylidene fluoride or polyvinylidene difluoride (PVDF) is a highly non-reactive thermoplastic fluoropolymer produced by the polymerization of vinylidene difluoride. Compared to other fluoropolymers, like polytetrafluoroethylene (Teflon), PVDF has a low density (1.78 g/cm3). It is denser than nylon.
In medical use, PVDF is used as an artificial membrane (usually with 0.22 or 0.45-micrometre pore sizes), on which proteins are transferred using electricity. PVDF is resistant to solvents and, therefore, these membranes can be easily stripped and reused to look at other proteins.
PVDF is used for specialty monofilament lines.
Polyvinylidene fluoride (PVDF) is a highly crystalline, thermoplastic fluoroplastic with relatively balanced mechanical properties. In comparison to PTFE, PVDF has significantly better stiffness and compressive strength, but also a considerably lower continuous operating temperature of only 150°C.
PVDF has a high resistance to high-energy radiation and is considered physiologically harmless.
Scientific studies from Aachen University (RWTH) Hospital demonstrate that lower quantities of bacteria adhere to textile implants made from pure PVDF (reduced bacterial adherence).
This is a significant finding for all open techniques because the risk of infection drops substantially with lower bacterial adherence. (source: FEG Textiltechnik)
A long-term trial (7 years):
- PVDF loses only 7.5% tensile strength
- PP loses 46.6% tensile strength
and stiffens
Reference: Laroche G, Marois Y, Schwarz E, Guigoin R, King M W, Pâris E, Douville Y: Polyvinylidene Fluoride Monofilament Sutures: Can They Be Used Safely for Long-Term Anastomoses in the Thoracic Aorta? Artificial Organs 19/11: 1190-1199; ©Blackwell Science, Inc., Bosten (12/1995)