Dynamic Interfacial Cross-Linking Polymer Blends with Fiber-Like Phase Structure by Recycling

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.