Electrochemical Monitoring of Super-Engineering Polymer Depolymerization: A Rapid and Simple Approach

Abstract

The mechanical properties and processability of polymers are strongly influenced by their molecular weight, underscoring the critical importance of controlling depolymerization during storage in polymer synthesis and application. However, conventional methods of determining molecular weight, including viscosity measurements, gel permeation chromatography (GPC), and nuclear magnetic resonance (NMR) spectroscopy, typically necessitate substantial quantities of polymer samples and protracted measurement times. Moreover, certain polymers may undergo continuous degradation post-polymerization, rendering depolymerization analysis via traditional means highly challenging. Hence, there is an imperative need to develop novel analysis techniques that overcome these limitations and facilitate comprehensive depolymerization characterization.To surmount these challenges, we have developed a novel electrochemical method utilizing cyclic voltammetry to facilitate polymer depolymerization measurement. For measuring degree of depolymerization, we used thermal depolymerization process. As the polymer's molecular weight diminishes because of thermal depolymerization, the solution viscosity decreases correspondingly, thereby enabling unimpeded redox species diffusion and a proportional increase in steady-state current. By constructing a calibration curve of current versus thermal depolymerization time for a polymer, we can swiftly and accurately determine its molecular weight tendency in solution. Our investigations indicate that this electrochemical technique is more efficient and cost-effective as it necessitates smaller sample volumes and shorter measurement times than conventional methods, and it exhibits excellent potential for analyzing and maintaining polymer properties across various industries.[1] Kim, J. W., Kim, S. J., Song, I. Y., Lee, W. E., Heo, K., Kim, S. Y., ... & Kim, B. K. (2022). Simple and rapid electrochemical monitoring for depolymerization of polyamic acid. Analytica Chimica Acta, 1233, 340489.