Xiaojiang Xie,Lihao Wu,Jizhong Huang,Jingwei He,Fang Liu
The traditional small molecular rubber antioxidants have the shortcomings of single function, toxicity, and heavy dependence on non-renewable fossil resources, which limits their green, high-efficiency, and sustainable development in the rubber industry. To address this problem, in this work, we first developed a chitosan derivative containing 10-undecenoyl groups (COS-UC) and then combined it with the natural small molecular antioxidant gallic acid (GA) to prepare chitosan derivative containing 10-undecenoyl and galloyl groups (COS-UC-GA). The obtained COS-UC-GA was used as multifunctional modifier and applied in styrene-butadiene rubber (SBR)/silica composites. The effects of COS-UC-GA on the curing characteristics, crosslinking density, morphology, mechanical properties, and interfacial interaction of SBR/silica composites were explored in detail. The results indicated that the COS-UC-GA can effectively accelerate the vulcanization process of SBR/silica compounds, promote the uniform dispersion of silica, improve the mechanical properties of SBR/silica composites, and significantly enhance the interfacial interaction between the silica and rubber. This research provides a new perspective for developing green and eco-friendly multifunctional modifiers, which not only contributes to the comprehensive utilization of biomass resources, but also can promote the green development of the rubber industry.
Phloroglucinols of Dryopteris fragrans (L.) Schott plant show strong antifungal activity. In previous work, we isolated a wide range of phloroglucinols from the plant and found that pseudoaspidinol of D. fragrans and its structural modifications (methylphloroglucinol derivatives) showed stronger antifungal activity and confirmed that the butyryl group of these compounds accounted for this activity. In this study, we designed a series of phloroglucinol derivatives ( A1–A9) and methylphloroglucinol derivatives ( B1–B9) by introducing acyl groups with diverse carbon numbers in the C-2 position, synthesized these compounds, and evaluated the anti-dermatophyte activity of compounds A1–A5 and B1–B5 on Trichophyton rubrum and Trichophyton mentagrophytes fungal species. The results showed that compound A5 exhibited the strongest activity. These compounds can be used as leads for the development of new antifungal agents.
A novel cross-linkable polyaspartamide derivative-containing cinnamoyl pendant groups, P(HPA-Az)-CA, was designed and synthesized in this study. Chemical structures of the obtained polymers were confirmed by FTIR, UV, and 1 H NMR techniques. The transmittance measurement results showed that the prepared polymer P(HPA-Az)-CA displayed temperature and pH dual stimuli-responsive behaviors. The cloud point of P(HPA-Az)-CA could be tuned just by adjusting the introduced percentage of hydrophobic moieties or the pH of polymer aqueous solution. The effect of pH on the cloud point of P(HPA-Az)-CA was investigated by zeta potential, and the results showed that it may be related to the weakened electrostatic repulsion caused by decreased zeta potential with pH decreasing. Diamines (ethylenediamine or cystamine) were adopted to prepare cross-linked micelles using the mixture of P(HPA-Az)-CA aqueous solution and diamines just by one-step heating method. The cross-linked micelles were stable, even when the environmental temperature was below the cloud point of P(HPA-Az)-CA. The cross-linking mechanism between the diamines and α,β-unsaturated carbonyl moieties of P(HPA-Az)-CA was confirmed by 1 H NMR. In addition, the micelles cross-linked with cystamine could be disrupted in the presence of 10 mM glutathione. According to the results, the obtained polyaspartamide derivative P(HPA-Az)-CA may be a potential for facilitating drug loading.
危险品化学品经营许可证（带存储）