Theoretical simulation of the structure–activity relationship of polyimide dielectric constant and analysis of its linear regression model

In this paper, two calculation methods, quantum mechanics and molecular dynamics, are used to simulate the polyimides with 12 different molecular structure models. First, a variety of structural parameters that may be related to the dielectric constant are screened out, including free volume fraction, solubility parameters, the most negative atomic net charge, etc. Then, a stepwise regression analysis model is constructed using the parameters and dielectric constant, preliminary identification of property parameters with significant correlation with dielectric constant, and in-depth analysis of the rationality, structure–activity relationship, correlation, and other aspects of the multiple linear regression model. The results indicate that the p -value is less than p = 0.000 < 0.05, and the design of the model has important practical value; There is an inherent relationship between the five structural parameters and the dielectric constant—solubility parameters are positively correlated with end distance/free volume and dielectric constant, while the net charge of the most negative atom, free volume fraction, length of side groups are negatively correlated with dielectric constant. In addition, increasing the free volume of polyimide is more effective than changing the polarity to reduce the dielectric constant of polyimide.