Trimethyl borate‐treated polytetrafluoroethylene micropowders with improved hydrophilic and adhesive properties based on coordination bond theory

Based on coordination bond theory, the current study proposes a novel method to modify the surface of the polytetrafluoroethylene (PTFE) micropowders. The samples were treated with trimethyl borate in the n‐hexane solution, and this improves the hydrophilic and adhesive properties of PTFE micropowders. The surface properties of treated samples were evaluated by using X‐ray photoelectron spectrometry, contact angle measurement, settling velocity measurement, and adhesive property measurement. Trimethyl borate treatment led to an evident increase in the hydrophilic and adhesive properties of PTFE micropowders. The water contact angle of PTFE micropowders decreased from 115° to 85.4°, while the ethanol contact angle of PTFE micropowders decreased from 39.8° to 11.2° owing to the combination of the trimethyl borate with PTFE micropowders as indicated by the X‐ray photoelectron spectrometry spectra. Furthermore, the settling velocity of powders dispersed in ethanol/water (1/10) solution (pH = 8.5) improved (with a settlement ratio exceeding 20% in 60 minutes), and the fracture stress of the powders/resin composite membrane increased from 4.68 to 6.67 MPa while the elongation at the yield of membrane increased from 25.4% to 31.5%.