In recent years, inverse gas chromatography (IGC) and molecular dynamics simulation methods have been used to characterize the solubility parameters and surface parameters of polymers, which can provide quantitative reference for the further study of the surface and interface compatibility of polymer components in the future. In this paper, the solubility parameters and surface parameters of two kinds of common alcoholysis, PVA₈₈ and PVA₉₉, are studied by using the IGC method. The accuracy of the solubility parameters obtained by the IGC experiment is verified by molecular dynamics simulation. On the basis of this, the influence of repeated units of polyvinyl alcohol (PVA) on solubility parameters is studied, so as to determine the appropriate chain length of the PVA for simulation verification calculation. The results show that the solubility parameters are not much different when the PVA chain length is 30 and above; the numerical trends of the solubility parameters of PVA₈₈ and PVA₉₉ at room temperature are the same as the results of molecular dynamics simulation; the dispersive surface energy ${\mathsf{\gamma }}_{\mathrm{s}}^{\mathrm{d}}$ and the specific surface energy ${\mathsf{\gamma }}_{\mathrm{s}}^{\mathrm{sp}}$ are scattered with the temperature distribution and have a small dependence on temperature. On the whole, the surface energy of PVA₉₉ with a higher alcoholysis degree is higher than that of PVA₈₈ with a lower alcoholysis degree. The surface specific adsorption free energy ($\Delta {\mathrm{G}}^{\mathrm{sp}}$) indicates that both PVA₈₈ and PVA₉₉ are amphoteric meta-acid materials, and the acidity of PVA₉₉ is stronger.

A new method has been developed for the high-value utilization of larch bark, which is regarded as a low-value byproduct of the logging industry. Polymeric proanthocyanidins (PPCs) were extracted from the Larix gmelinii bark and depolymerized by catalytic hydrogenolysis, using ruthenium/carbon (Ru/C) as the catalyst. The method has been found that although the molecular weight of the depolymerized product was significantly lower, the basic structural units were not destroyed, and the product retained a condensed flavanol polyphenol structure; the depolymerized product contains very little Ru metal and thus complies with food safety standards; the antioxidant properties of both the depolymerized products and PPCs were better than those of the commonly used antioxidant 2,6-di-tert-butyl-4-methylphenol. The relative molecular weight and steric hindrance of the depolymerized products were lower than those of the PPCs, leading to better antioxidant performance. A new technical route for the depolymerization of PPCs from the L. gmelinii bark is provided. The route offers practical and commercial advantages, and the product could have many applications as an antioxidant.