Engineering tunable dual dynamic networks toward strong yet reversible adhesion, healable and recyclable polyolefin elastomer-based adhesives

Abstract

Developing sustainable adhesives from commodity polyolefins that integrate strong adhesion and dynamic properties is highly desirable, but has proved to be extremely challenging. Herein, a strong yet reversible adhesion, healable and recyclable polyolefin elastomer (POE)-based adhesive is developed by fabricating the tunable dual dynamic networks (DDNs) of the epoxy-functionalized POE and epoxidized soybean oil sub-networks. The resultant adhesive is able to establish strong interfacial bonding with heterogeneous substrates such as inorganics, polymers, metals and fibers through massive reversible interactions, and features adhesion stability in various harsh environments. Besides, owing to the reconfigurable nature of the DDNs, the adhesive demonstrates the ability to on-demand debond and re-bond to the substrate, and its adhesion strength remained undecayed even after more than 10 adhesion cycles. Notably, the DDNs allow the adhesive to be healed by thermo-activated exchange reactions with healing efficiency of up to 86%. Meanwhile, the adhesive can be recycled and reused more than 10 times. More importantly, the end-of life adhesive can also be readily chemically recycled by selective cleavage of disulfide bonds. This work provides a facile and scalable route toward the preparation of adhesives with comprehensive functions through the rational design and construction of multi-dynamic networks.