Virgin PVDF

Virgin PVDF

Structure and Performance of PVDF

• Polyvinylidene fluoride (PVDF) contains alternating CH2 and CF2 groups. These alternating units can crystallize with larger CF2 groups adjacent to smaller CH2 units on adjacent chains. This interpenetrating structure produces high modulus, resulting in the flexural modulus of PVDF being the highest among all fluoropolymers.
• The above-mentioned alternating groups generate dipoles, making the polymer soluble in highly polar solvents such as dimethylformamide, tetrahydrofuran, acetone and esters.
• Other consequences of this structure are high dielectric constant, high dielectric loss factor, and piezoelectric behavior under certain conditions.
• The shielding effect of the fluorine atom adjacent to the CH2 group provides the polymer with good chemical resistance and thermal stability.

Applications

• PVDF can be used as a biological material to synthesize monofilament vascular sutures. Heat treatment and coloring will change the crystal microstructure and affect the mechanical properties to a certain extent. Although the sterilization treatment will cause some changes in the crystal microstructure near the surface of the monofilament, it will not change the mechanical property. Studies have shown that PVDF has good biocompatibility, combined with its ideal characteristics such as easy handling and satisfactory mechanical strength, making it an attractive alternative to monofilament suture materials that can be used in cardiovascular surgery.

Figure 1. The changes in the crystal structure of PVDF samples caused by coloring, heat treatment and sterilization as observed by DSC [1]

• Due to its outstanding characteristics such as high thermal stability, good chemical resistance and film-forming properties, PVDF has been widely used in scientific research and industrial processes in the form of membranes. The application fields of PVDF membrane include water treatment, membrane distillation, gas separation, pollutant removal, bioethanol recovery, lithium ion battery diaphragm, and support for preparing composite membranes. For example, PVDF can be made into a porous membrane to absorb acid gas (Figure 2).

Figure 2. Schematic diagram of the absorption of acid gas through porous PVDF membrane contactor [2]

• Using the electrospray method, PVDF is prepared into microparticles as a suitable substrate for tissue engineering applications. During the electrospray preparation process, the polymer concentration has a great influence on the formation of PVDF particles. A higher concentration promotes the formation of fibers, and a diluted or semi-diluted concentration is conducive to the formation of PVDF particles. Studies have shown that MC-3T3-E1 cell adhesion is not inhibited by PVDF microparticle preparations, indicating that this material is suitable for the development of electroactive scaffolds for biomedical applications.

Figure 3. The effect of polymer concentration on the morphology of PVDF microparticles [3]

References

1. Gaétan Laroche, Yves Marois, Robert Guidoin, Martin W. King, Louisette Martin, Thien How, Yvan Douville, Journal of Biomedical Materials Research 29 (1995) 1525-1536.
2. Guo-dong Kang, Yi-ming Cao, Journal of Membrane Science 463 (2014) 145-165.
3. D. M. Correia, R. Gonçalves, C. Ribeiro, V. Sencadas, G. Botelho, J. L. Gomez Ribelles, S. Lanceros-Méndez, RSC Advances 4 (2014) 33013-33021.

Get in touch with us

If you have any services of interest, you are welcome to contact us to discuss the solutions that best suit your requirements.