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Crumb rubber could form the active groups on the surface by interrupting the crosslinking bond to improve the compatibility with asphalt. While styrene-butadiene-styrene block copolymer (SBS)-modified asphalt has excellent comprehensive properties, it has poor anti-aging performance and a high cost. To explore the influence of composite modification of activated crumb rubber powder (ACR) and SBS on asphalt, modified asphalt samples with different modifiers and SBS contents were prepared. Conventional physical properties tests, a dynamic shear rheometer (DSR), and the thin-film oven test (TFOT) were used to study the conventional physical properties, high-temperature rheological properties, and aging resistance of asphalt. In addition, the action forms and distribution of modifiers in asphalt were observed by an optical microscope to characterize the micro-morphology of ACR/SBS composite-modified asphalt. Test results showed that after adding SBS, the softening point, ductility, and elastic recovery of ACR/SBS asphalt could be significantly improved, but the viscosity and softening point difference were also larger. At the same time, according to the complex shear modulus, phase angle, and rutting factor, SBS can effectively improve the high-temperature deformation resistance of ACR/SBS asphalt. The modified asphalt (ACR/SBS-2) had good high- and low- temperature performances, as well as an appropriate viscosity and low softening point difference, as a research object of aging. After short-term aging, the changes in the high- and low-temperature performances and workability of ACR/SBS asphalt were reduced. Taking the softening point as the target performance, the softening point of ACR/SBS asphalt was less affected by aging time and temperature, indicating that ACR/SBS asphalt was not sensitive to aging temperature and had good stability and aging resistance. From the micrograph by microscope, it was found that ACR/SBS asphalt could maintain a relatively stable polyphase structure for aging resistance. [ABSTRACT FROM AUTHOR]

Fish gelatin hydrogels are typically characterized by weak texture and poor thermal stability. To address this issue, fish gelatin (FG) was modified using κ-carrageenan (κC) and transglutaminase (TG). FG-κC, FG-TG, and FG-κC-TG gels were prepared. The results demonstrated that the particle size and textural properties of FG gels were significantly enhanced by κC and κC-TG composite modifications, and their zeta potential was reduced (P < 0.05). As opposed to that, the improvement effects of TG modification were weaker. The highest particle size and hardness, along with the lowest zeta potential, were exhibited by the FG-κC-TG 0.06% gel. Additionally, the FG-κC-TG gel system possessed higher apparent viscosity and elastic storage modulus. Fluorescence spectroscopy and UV absorption analysis indicated that fluorescence intensity was reduced by all three modification methods, and the conformational structure of FG was altered to varying degrees. Microstructure, FTIR, and XRD results revealed that the number of hydrogen bonds and isopeptide bonds in the composite gel systems was increased by κC and κC-TG modifications, enhancing the stability and orderliness of the gel's helical structure, and forming larger aggregates and denser network structures. Furthermore, due to the presence of covalent cross-linking, improved thermal stability was exhibited by the modified gelatin hydrogels. This study not only provides theoretical support for enhancing the performance of fish gelatin but also facilitates the application of modified fish gelatin in improving the sensory quality and flavor characteristics of food, as well as in serving as a matrix material in the biomedical field. [Display omitted] • The improvement effect of composite modification on FG is the most significant. • The FG-κC-TG gel exhibited superior rheological and textural properties. • Hydrogen and isopeptide bonds are associated with the ordered helical structures in FG. • The thermal stability of FG is improved after modification. [ABSTRACT FROM AUTHOR]