# Sustainable Structural Hot‐Melt Adhesives Enabled by Functionalized Crystalline Lamellae

## TL;DR

A sustainable, high-strength hot-melt adhesive is developed using renewable materials that can be fully recycled and performs well on various surfaces.

## Contribution

The development of a recyclable hot-melt adhesive with functional crystalline lamellae that combines high performance and sustainability.

## Key findings

- The adhesive achieves shear strengths above 14.7 MPa on wood and 15.1 MPa on stainless steel.
- The material exhibits excellent oxygen and water vapor barrier properties suitable for microelectronic encapsulation.
- The adhesive can be fully depolymerized under mild hydrogenation to regenerate original monomers.

## Abstract

Conventional hot‐melt adhesives (HMAs) suffer from low shear strength and poor recyclability, limiting their structural applications. Here, a sustainable HMA system is developed from renewable building blocks that combines strong adhesion with closed‐loop chemical recyclability. Incorporating polar functional groups into crystalline lamellae enables efficient stress transfer through rigid domains, achieving a balance between cohesive and adhesive forces. The resulting sulfur‐based polymers exhibit shear strengths above 14.7 MPa on wood and 15.1 MPa on stainless steel, along with excellent oxygen and water vapor barrier properties suitable for microelectronic encapsulation. Moreover, these materials can be fully depolymerized from a mixed materials system under mild hydrogenation to regenerate the original monomers. This work establishes a design strategy for structural HMAs that unifies high performance, sustainability, and recyclability.

A high‐performance, recyclable hot‐melt adhesive is developed from renewable materials. It features functional crystalline lamellae that enhance shear strength and enable closed‐loop recycling. The adhesive also provides excellent water and oxygen barrier properties, meeting both sustainability and performance demands for advanced bonding and sealing applications.