The properties of polymer blends strongly depend on their microstructure. Thus, tuning the phase structure and improving the interfacial interaction of blends are relatively crucial. Inspired by the breaking and reformation of dynamic covalent bonds in vitrimers, these special bonds are introduced into the phase interface of polymer blends in this work. Through reactive blending of epoxidized natural rubber (ENR), polylactic acid (PLA) and additives, polymer blends with dynamic interfacial cross‐linking are fabricated. The prepared blends with intensive interfacial interactions display excellent recycling capacity. Strikingly, after etching the dissolvable substances with a solvent, the porous phase structure of original polymer blends changes to a fiber‐like phase structure of the third recycled blends, entirely distinct from most reported phase structures in polymer blends. In addition, the composites show great enhancements in mechanical properties during recycling. This work provides an effective method to tune the phase structure and improve the interfacial interaction of polymer blends.

The rapid development of photochromic devices has stimulated great enthusiasm for the design and preparation of luminescent materials. Introducing fluorescent powder ZnS:Cu into the cross-linked polymer matrix is an efficient and simple method to obtain photochromic materials with excellent comprehensive performance. However, the traditional method is to directly introduce fluorescent powder into the polymer matrix by physical mixing. This not only increases the internal defects of the polymer and reduces the mechanical properties, but also hinders the fluorescent powder from absorbing external energy and reduces its luminescence efficiency. In addition, few studies have focused on recyclable photochromic luminescent materials. Inspired by dynamic covalent cross-linking technology, this paper first modified fluorescent powder with 3-mercaptopropionic acid and then introduced it into epoxy silicone rubber to prepare recyclable luminescent elastomer. Compared with traditional physical blending, the mechanical properties and luminescence performance of the covalently bonded luminescent elastomer were improved. Excellent mechanical properties and luminescence performance were maintained in multiple recycling processes. This paper provides a feasible and simple scheme for the preparation of recyclable luminescent elastomers, paving the way for the recycling and long-term utilization of photochromic luminescent materials.