Programmable Compressing and Decompressing for Controllable Polymerization: The Case of Methyl Methacrylate

Conventional high-pressure chemical reactions that are initiated by manual compression or decompression face critical challenges in reproducibility, as different research groups often obtain different results. In this study, we developed a new high-pressure technique termed programmable compression and decompression (PCD) in order to solve this problem. This versatile method allows us to arbitrarily adjust the pressure loading modes, including the compression and decompression rates, the amplitude, and the number of compression–decompression cycles, to explore their effects on chemical reactions. Using the polymerization of methyl methacrylate (MMA) as a model reaction, our PCD technique shows that the characteristic of the pressure-induced polymerization (PIP) of MMA is “high-pressure initiation and low-pressure polymerization”. The effects of the initiation pressure, polymerization pressure, and holding time at low pressure were confirmed by simple compression and decompression experiments. Furthermore, using the PCD technique, we set several pressure loading modes to explore the effects of the number of compression–decompression cycles, amplitude, and rate on MMA polymerization. The results show that the number of compression–decompression cycles and the amplitude significantly affect the conversion yield (CY). Our results demonstrate that the PCD technique is a convenient method for controlling high-pressure reaction conditions and provide some inspiration for future high-pressure technology.