Flexible Cyclic-Poly(phthalaldehyde)/Poly(ε-caprolactone) Blend Fibers with Fast Daylight-Triggered Transience

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Cyclic-poly(phthalaldehyde) (cPPHA) is a photo-triggerable polymer suitable for photolithography but suffers from brittleness and thermal sensitivity.
• Existing plasticizers for cPPHA can leach out, compromising long-term flexibility and material integrity.
• Developing flexible and durable cPPHA-based materials is crucial for expanding its engineering applications.

Purpose of the Study:

• To develop flexible and transient cyclic-poly(phthalaldehyde) (cPPHA) fibers through blending with poly(ε-caprolactone) (PCL).
• To investigate the effect of blend composition and gold nanoparticle incorporation on the mechanical properties and photo-triggered depolymerization rate of cPPHA/PCL fibers.
• To explore the potential of these novel fibers in applications requiring on-demand degradation and flexibility.

Main Methods:

• Fabrication of cPPHA/PCL blend fibers using a modified wet spinning technique.
• Characterization of fiber mechanical properties, including tensile strength, Young's modulus, and elongation at break.
• Evaluation of photo-triggered depolymerization rates under daylight exposure, with and without gold nanoparticle inclusion.

Main Results:

• The 50/50 cPPHA/PCL fiber blend demonstrated excellent flexibility, retaining PCL's elastomeric properties (tensile strength ≈8 MPa, Young's modulus ≈118 MPa, elongation at break ≈190%).
• These fibers exhibited rapid daylight-induced transience in under 50 seconds.
• Incorporating 2 wt% gold nanoparticles accelerated the depolymerization rate in fibers with less than 50% cPPHA.

Conclusions:

• Flexible and daylight-triggerable cPPHA/PCL fibers have been successfully fabricated, overcoming the inherent brittleness of cPPHA.
• The developed fibers offer tunable mechanical performance and rapid on-demand depolymerization, making them suitable for advanced material applications.
• Potential applications include wearable electronics, intelligent textiles, and sustainable zero-waste packaging solutions.