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The thermal oxidation characteristics of abietic acid were investigated through tracing the oxidation process in custom-designed mini closed pressure vessel test under isothermal and step temperature conditions. Peroxide generation and the peroxide value of abietic acid oxidation process were measured using thin-layer chromatographic analysis and iodimetry. The primary oxidation productperoxidewas separated by column chromatography with further structure characterization, and its thermal decomposition characteristics were assessed via a differential scanning calorimeter (DSC). The oxidation was mainly initiated through the radical generation from hydrogen abstraction on the unsaturated conjugated double bonds of abietic acid above 343 K. The main hydroperoxide, 7-hydroperoxy-13-abiet-8(14)-enoic acid, was found in abietic acid with a high peroxide value. The exothermic onset temperature (T 0) and decomposition heat (Q DSC) of this peroxide were 353.94 K and 545.37 J·g–1, respectively. Finally, a second-stage oxidation process of abietic acid was first investigated when the temperature reached the abietic acid melt point (448 K) with complex oxidation products forming, such as dehydroabietic acid, palustric acid, 7-oxodehydroabietic acid, neoabietic acid, 7-methoxy-tetradehydroabietic acid, 12-deoxyroyleanone acid, and 12-methoxy-abietic acid.

D-psicose 3-epimerase (DPEase) catalyzes the isomerization of D-fructose to D-psicose (aka D-allulose, a low-calorie sweetener), but its industrial application has been restricted by the poor thermostability of the naturally available enzymes. Computational rational design of disulfide bridges was used to select potential sites in the protein structure of DPEase from Clostridium bolteae to engineer new disulfide bridges. Three mutants were engineered successfully with new disulfide bridges in different locations, increasing their optimum catalytic temperature from 55 to 65 °C, greatly improving their thermal stability and extending their half-lives (t1/2) at 55 °C from 0.37 h to 4–4.5 h, thereby greatly enhancing their potential for industrial application. Molecular dynamics simulation and spatial configuration analysis revealed that introduction of a disulfide bridge modified the protein hydrogen–bond network, rigidified both the local and overall structures of the mutants and decreased the entropy of unfolded protein, thereby enhancing the thermostability of DPEase.

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This study resolves the poor enhancement problem of high‐temperature performance and lower dissolution of styrene‐butadiene‐styrene (SBS) modified asphalt and soybean bio‐asphalt (SBA) (extracted from waste soybean oil) by tannic acid (TA) modified bamboo fiber (MBF). The rheological properties and microscopic morphologies of the modified asphalt and fibers were investigated by dynamic shear rheometer (DSR), multiple stress creep recovery (MSCR) tests, and Fourier transform infrared (FTIR) spectroscopy. The results showed that the rutting factor and deformation recovery rate of 3% MBF/3% SBS/SBA modified asphalt at 64°C increased by 78.4% and 31.99% as compared with those of 5% SBS modified asphalt. Further, the phenolic hydroxyl group of TA reacted with C═O groups in SBA to form a strong connection between BF and bio‐asphalt. Fluorescence microscopy analysis revealed that SBS solubilization and BF formed a uniform and stable network structure in the modified asphalt. This study provides a useful, greener, and cost‐effective strategy for the effective utilization of industrial waste (BF and waste soybean oil) by converting into advanced functional materials for highway and construction industries novel and hence can concomitantly decrease environmental pollution and enhance energy conservations.

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