Non-isocyanate Polyurethane Coating with High Hardness, Superior Flexibility, and Strong Substrate Adhesion

Area of Science:

• Materials Science
• Polymer Chemistry

Background:

• Flexible hard coatings with strong adhesion are essential for advanced applications like foldable electronics and marine environments.
• Existing coating technologies often struggle to meet these combined requirements.

Purpose of the Study:

• To develop a novel non-isocyanate polyurethane (NIPU) coating with exceptional hardness, flexibility, and substrate adhesion.
• To explore the potential of incorporating functional properties such as anti-icing and self-cleaning.

Main Methods:

• Synthesized NIPU coatings via a dual curing process: epoxy-oligosiloxane nanocluster-amine reaction for hardness/flexibility and cyclic carbonate-amine polyaddition for adhesion.
• Characterized coating properties including transparency, hardness (5-7 H), flexibility (2 mm bending diameter), and adhesion strength (2-8 MPa) to various substrates.
• Incorporated amine-terminated polydimethylsiloxane (PDMS) to impart anti-icing, self-cleaning, and anti-smudge functionalities.

Main Results:

• The NIPU coating exhibited high transparency (>92%), hardness, flexibility, and strong adhesion to diverse substrates (aluminum alloy, titanium, steel, glass, etc.).
• The dual curing mechanism effectively balanced ceramic-like hardness with polymer-like flexibility.
• Functionalization with PDMS provided anti-icing, self-cleaning, and anti-smudge properties with minimal impact on mechanical performance.

Conclusions:

• The developed NIPU coating offers a promising solution for flexible hard coating requirements in foldable devices and marine applications.
• The synthesis strategy allows for tunable properties and the integration of multifunctional surface characteristics.
• This novel coating technology demonstrates significant potential for enhancing the performance and durability of various technological applications.