Surface bio-modification of poly(hydroxybutyrate-co-hydroxyhexanoate) and its aging effect

Area of Science:

• Materials Science
• Polymer Chemistry

Background:

• Poly(hydroxybutyrate-co-hydroxyhexanoate) (PHBHHx) is a biodegradable polymer with potential applications.
• Improving the surface hydrophilicity of PHBHHx is crucial for certain applications.
• Surface modification techniques can alter polymer properties.

Purpose of the Study:

• To enhance the surface hydrophilic property of PHBHHx film.
• To investigate the effect of NaOH treatment on PHBHHx surface characteristics.
• To understand the aging behavior of the modified PHBHHx film.

Main Methods:

• Solution-casting method for PHBHHx film fabrication.
• NaOH treatment for surface modification.
• Water contact angle measurement, Scanning Electron Microscopy (SEM), and X-ray Photoelectron Spectroscopy (XPS) for characterization.

Main Results:

• NaOH treatment significantly improved the hydrophilicity of PHBHHx film.
• Surface topography changes and introduction of polar groups (hydroxyl, carboxyl) contributed to increased hydrophilicity.
• An aging effect was observed, where hydrophilicity decreased over time.
• Aging rate was dependent on film crystallinity and storage environment; higher crystallinity and low-temperature storage slowed hydrophilicity loss.

Conclusions:

• NaOH treatment is an effective method to enhance PHBHHx film hydrophilicity.
• The enhanced hydrophilicity is susceptible to aging, influenced by intrinsic material properties and external conditions.
• Controlling crystallinity and storage environment can mitigate the aging of modified PHBHHx films.