Baroplastics with Ultrahigh Strength and Modulus via Hydrogen-Bonding Interactions with Agar

For the traditional processing of polymers, a high temperature, generally above 200 °C, is needed to melt the polymers. The high temperature not only causes a large amount of energy consumption but also thermal degradation of the polymers. In this work, we have prepared a representative baroplastic poly(n-butyl acrylate)@polystyrene (PBA@PS) core–shell polymer, which can be processed at a much lower temperature multiple times to overcome the above-mentioned problems. To address their poor mechanical property issue, such as weak strength and low modulus, we introduced stronger hydrogen bonds of agar into PBA@PS matrix. The results show that the PBA@PS/agar composites possess significantly improved strength and ultrahigh modulus, much higher than that of previously reported core–shell baroplastics. The tensile strength and Young’s modulus are as high as 8.4 and 350.6 MPa, respectively, which are enhanced by 265 and 4702% compared with the pure PBA@PS baroplastic. The reinforcement results from the hydrogen bonds of agar. In addition, the baroplastics can be repeatedly processed at 100 °C at the same condition with a small loss of mechanical properties. This work provides a way to strengthen the baroplastics and thus increases their application potential.