Water dispersible polytetrafluoroethylene microparticles prepared by grafting of poly(acrylic acid)

• Preparation of water dispersible PTFE microparticles via grafting AA onto surface.
• Hydrophilicity of PTFE-g-AA was significantly improved via neutralization of NaOH.
• A very stable PTFE-g-NaAA aqueous solution can be easily prepared.

Due to the hydrophobic nature and high gravimetric density, it is very difficult to obtain water dispersible polytetrafluoroethylene (PTFE) powder. In this work, hydrophilic PTFE microparticles were successfully prepared by grafting of poly(acrylic acid) onto PTFE micropowder via a pre-irradiation method. The as-obtained hydrophilic PTFE microparticles were analyzed by FT-IR, 1H NMR, CA, SEM and TGA. After neutralization by sodium hydroxide, the water contact angle decreased from 145.69° for pristine PTFE to 63.38° for PTFE-g-NaAA. The obtained micropowder can be easily dispersed in water to form a dispersion with very high stability. Furthermore, the presence of grafted PAA shows no obvious influence on degradation temperature of PTFE backbones.