U.S.-Hong Kong scientists have developed a new high-polymer material using "computational chemistry."

　　Computational chemistry ushers in a new type of ultra-strong, self-healing polymer material.

　　It holds the potential to bring about transformative changes in industries such as transportation, aviation, and microelectronics.

　　According to a report by the Science and Technology Daily, recently, scientists from IBM Research in the U.S., in collaboration with institutions including the University of California, Berkeley, and Eindhoven University of Technology in the Netherlands, have combined laboratory experiments with high-precision computational modeling through "computational chemistry" to simulate the formation reactions of new materials. As a result, they have developed two novel high-polymer materials that can be recycled, which hold promise for revolutionizing manufacturing processes in industries such as transportation, aerospace, and microelectronics.

　　According to a recent report by Phys.org, these new materials first of all exhibit crack-resistant properties and boast strength exceeding that of bone. They can also deform and self-heal, with the entire material fully reverting to its original composition. Moreover, these materials can “transform” into new polymeric structures, increasing their strength by another 50% and becoming yet another ultra-strong, lightweight material. The relevant paper was published in that day’s issue of the journal Science.

　　Aerospace materials need to exhibit excellent crack resistance. However, current polymer materials have limited crack-resistance capabilities and are difficult to recycle—they cannot be remelted, self-heal, or thermally decomposed. As a result, waste materials can only be disposed of by landfilling as solid waste. What the research team has discovered is a new “family” of materials whose properties can be widely tuned to meet specific requirements, opening up even more opportunities for exploration, research, and application development. The two novel materials they have developed each possess unique characteristics, including high hardness, resistance to dissolution, and enhanced self-healing capabilities that allow cracks to heal themselves.

　　These novel polymeric materials are made from inexpensive raw materials. Through a condensation reaction, large molecules link together, while small molecules are released as water or ethanol. The reaction is simple and easy to control. At 250°C, the polymer undergoes reorganization via covalent bonds, and after solvent removal, it becomes stronger than bone—but its main drawback is that it’s brittle and prone to cracking. It remains completely intact in high-pH aqueous solutions, yet selectively decomposes in low-pH environments. Under appropriate conditions, therefore, it can reversibly return to its original material form, allowing it to re-form a new polymeric structure. Moreover, when the polymer is mixed with carbon nanotubes or other reinforcing fillers and then heated at high temperatures, it becomes significantly stronger and acquires metal-like properties, making it suitable for use in aircraft and automobiles.

　　At room temperature, it can form another type of polymer material that resembles elastic胶. The solvent is embedded within the polymer network, giving this material not only higher strength than most polymers but also maintaining flexibility—just like a rubber band. If it cracks, simply putting the fragments back together will allow chemical bonds to reform within seconds, seamlessly rejoining the material into a single whole. This unique property enables the material to be recycled in neutral environments and makes it particularly well-suited for applications requiring reversible reassembly.

　　Researchers point out that this unconventional approach will give rise to many unprecedented new materials and accelerate the material development process. “Although research on high-performance materials has made tremendous progress, currently designed polymer materials still lack many fundamental properties. Innovation in new materials is crucial for addressing global challenges and developing new products,” said James Hedrick, an advanced organic materials scientist at IBM Research. “Now, we can use computational methods to predict how molecules will behave during chemical reactions and create novel polymer structures, thereby driving the development of new materials and meeting the demand for sophisticated, advanced materials in industries such as transportation, microelectronics, and advanced manufacturing.” (Chang Lijun)