A thermoreversible crosslinking hot-melt adhesive: reversibility and performance

Area of Science:

• Materials Science
• Polymer Chemistry
• Adhesive Technology

Background:

• The demand for sustainable and recyclable hot-melt adhesives is increasing.
• Traditional adhesives often lack environmental friendliness and reusability.
• Diels-Alder (DA) chemistry offers potential for creating thermoreversible networks.

Purpose of the Study:

• To develop a new thermoreversible crosslinking hot-melt adhesive using the Diels-Alder reaction.
• To investigate the properties and recyclability of the novel adhesive.
• To enhance the environmental friendliness of hot-melt adhesive technology.

Main Methods:

• Synthesized furoic acid (FA)-grafted poly(vinyl alcohol) (PVA-g-FA) via esterification.
• Formulated the hot-melt adhesive by mixing PVA-g-FA with N,N'-(4,4'-methylenediphenyl)dimaleimide (MDI).
• Characterized the thermoreversible crosslinking behavior and adhesive performance.

Main Results:

• The PVA-g-FA/MDI adhesive exhibited thermoreversible crosslinking, occurring at 80 °C and reversing at 120 °C.
• Achieved superior peeling strength (43.33 N mm⁻¹) and bond strength (11.84 MPa) compared to standard PVA.
• Demonstrated good thermal conductivity (0.263 W m⁻¹ K⁻¹) and reusability over two cycles.

Conclusions:

• The developed PVA-g-FA/MDI adhesive offers a sustainable and recyclable alternative in hot-melt adhesive applications.
• The Diels-Alder reaction facilitates dynamic crosslinking, enabling efficient material reuse.
• The adhesive shows promising performance characteristics for various bonding applications.