Density functional theory study on bond dissociation energy of polystyrene trimer model compound

Abstract

The bond dissociation energy (BDE) of syndiotactic polystyrene(s-PS) was calculated by using four density functional theory methods, which were M062X, B3LYP, B3P86, BH and HLYP with different LANL2DZ, 6-31G(d), 6-31G(d, p), and 6-311++G(d, p) basis sets. The influence of these computational methods on the accuracy of the BDE of s-PS was analyzed. It was found that the BDE had a higher accuracy at B3P86/6-31G (d, p) level than other methods, and B3P86/6-31G (d, p) spent more less time to calculate the bond dissociation energy of s-PS, and the average of the C-C bonds’ BDE values calculated by B3P86/6-31G (d, p) is about 8.3 kJ/mol lower than the experimental value (310.0 kJ/mol), which is derived from the i-bond database. Besides, the bond dissociation energy values of the C-C bonds computed by M062X/LANL2DZ, B3LYP/6-31G(d), M062X/6-31G(d), B3LYP/LANL2DZ and BH and HLYP/6-311++G(d, p) methods were as follows: 330.8 kJ/mol, 345.3 kJ/mol, 283.2 kJ/mol, 267.6 kJ/mol, 267.4 kJ/mol. The calculation conclusion is drawn that different calculation methods with the same basis set have an obvious influence on the result of BDE values’ calculation. Finally, based on the calculation of bond dissociation energy of polystyrene, three possible reaction paths of polystyrene pyrolysis are designed to analyze the influence of bond dissociation energy on polystyrene pyrolysis.

Thermal Analysis of Plastics Used in the Food Industry

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Hydrothermal deconstruction of single-use personal protective equipment during the COVID-19 pandemic

“…As for FFR-II, 13820 mg/L, 6713.3 mg/L and 2343.3 mg/L tCOD contents were detected at 250 °C, 300 °C and 350 °C, respectively. The tCOD reduction was more for FFR-I than FFR-II because of a lower concentration of polyolefins FFR-I compared to FFR-II, which require a higher bond dissociation energy compared to other plastics (polystyrene) ( Huang et al, 2020 , Yeung et al, 2021 ), and therefore, increasing the tCOD content at harsh reaction conditions.…”

Synthesis of azole-functionalized microspheres and their adsorption properties for gold(i) thiosulfate complex

“…24 To obtain more reliable and accurate values, the 6-311++G** basis set was used, which defined elements C, H, N, S, Cl, and O, and the LANL2DZ basis set was used to optimize metallic elements. 25…”