Self-healing thermally conductive adhesives

Abstract

Thermally conductive composites with a temperature-triggered self-healing response were produced by dispersing boron nitride or graphite particles into two types of polysulphide-based thermoset matrices. The composites produced exhibit recovery of both cohesion and adhesion properties upon thermally activated healing. Using a mild healing temperature (65°C), the materials show full recovery of their initial adhesive strength during multiple healing cycles. The composites behave differently regarding the cohesion recovery: 20%–100% recovery is achieved depending on the filler type, filler loading and the type of matrix. The thermal conductivity of the composites increases with the amount of filler. Values of 1 and 2 W/m K can be achieved for the boron nitride and graphite-based composite, respectively. The results presented in this work clearly show that multifunctional materials with different functionalities and mechanical self-healing responses can be designed using this strategy.

A Review on the Potential and Limitations of Recyclable Thermosets for Structural Applications

“…For example, thermal interface materials were developed that show easy repair capacity of the thermal conductivity using associative disulfide linkages. 176,177 Furthermore, flexible electronics that are capable of restoration of the electronic conductivity due to the presence of dynamic DA 178,179 and polyimine 180 linkages were reported. The repair in these concepts is often triggered by a thermal stimulus that is already applied due to intrinsic use and that the functional polymers are often shielded from environmental hazards such as moisture.…”

Self‐healing polymeric materials towards non‐structural recovery of functional properties

“…Owing to thermally triggered reversible disulfide exchange reactions, the polymers exhibit both adhesive and cohesive self‐healing properties. Then, six types of thermally conductive filler particles (graphite, aluminium, copper, aluminium nitride, boron nitride and diamond) were each added to produce self‐healing thermally conductive polymer composites . Boron nitride and graphite are found to be the two best suited additives because they affect the self‐healing efficiency the least.…”

Micropatterned Down‐Converting Coating for White Bio‐Hybrid Light‐Emitting Diodes

“…The matrix components must enable an easy fabrication of the packing system, which must feature both high thermal‐ and photostability, high optical transmittance, and a refraction index > 1.5 . As the most popular approach, curable silicone‐based packings have been utilized in inorganic LEDs, showing stability problems related to photo‐ and thermal‐assisted chemical reactions that deteriorate the optical features over time under device operation conditions . In WHLEDs, the use of silicones and other UV‐ or thermal‐curable sealing reagents was proposed in early works, showing additional issues related to the degradation of the luminescent compounds and a prominent phase separation upon packing fabrication.…”