Baroplastics with Robust Mechanical Properties and Reserved Processability through Hydrogen-Bonded Interactions

Conventional polymers are usually processed at a much higher temperature than room temperature, which inevitably leads to huge energy consumption and degradation of the polymers and thus a low recycling ability. Herein, we synthesized a poly(n-butyl acrylate)@polystyrene (PBA@PS) core-shell polymer to prepare a typical baroplastic (processible at room temperature). However, this type of baroplastics always has a low mechanical property. To solve this problem, in this work, we introduced hydrogen bonds into the matrix and successfully reinforced baroplastics for the first time. The hydrogen-bonded interaction was introduced by complexing PBA@PS with poly(acrylic acid) and poly(ethylene oxide). The results show that the reinforced baroplastics possessed notably enhanced mechanical properties and good processability. Their mechanical strength and modulus reached as high as 5.6 (by 73%) and 10 MPa (by 400%), respectively. Moreover, the baroplastics could be remolded many times at room temperature and, at the same time, still showed a higher tensile strength (10.5 MPa, 3.3 times that of the initial PBA@PS, which was never achieved in previous works), which resulted from the reversible hydrogen bonds and reserved orientation of molecular chains. Our work opened a new path to reinforce baroplastics and could widen their applications. Furthermore, not limited to the hydrogen bonds, more sacrificial bonds, such as ionic bonds, host-guest interactions, and metal-ligand coordination bonds, could be used to fabricate high-performance baroplastics.