Yunbo Yu,Mengen Zhang,Congjing Ren,Ruijia Wang,Yao Yang,Tinghao Jia,Jingdai Wang,Yongrong Yang
Cycloalkanes are the main portion of petroleum hydrocarbons, yet their inert reactivity has put considerable technical challenges to efficient utilization. In this study, the liquid phase pre-oxidation process for efficient self-initiation cracking of cycloalkanes is proposed. In this process, a portion of decalin was converted into hydroperoxy-decalins. These hydroperoxy-decalins not only decompose more readily than decalin due to their weak O-O bonds but also continuously generate free radicals to accelerate the chain initiation reactions, thereby promoting the cracking of residue decalin. The experimental results indicate that the liquid phase pre-oxidation process can significantly improve both the conversion of decalin and the yield of high-value chemicals under 630–680 ℃, and the promotion efficiency increases with the oxidation depth. Compared to gas phase oxidative cracking, the liquid phase pre-oxidation cracking of decalin presents remarkably higher overall conversion and lower carbon oxides yield at elevated temperatures. Comprehensive kinetic models were established by the Reaction Mechanism Generator (RMG) and the reaction process was simulated using Chemkin-pro software packages to elucidate the underlying self-initiation mechanism of liquid phase pre-oxidation. This study introduces a novel promising approach for the efficient utilization of cycloalkanes in the production of high-value chemicals.
Qing Wang,Guangxue Chen,Yanyan Cui,Junfei Tian,Minghui He,Jian-Wen Yang
In this paper, we reported castor oil based biothiol (CO-SH) as a highly stable and self-initiated oligomer for photoinitiator (PI)-free UV coating. CO-SH was synthesized via esterification reaction between castor oil (CO) and 3-mercaptopropionic acid (MPA). The results of both proton nuclear magnetic resonance (1H NMR) and Fourier transform infrared spectroscopy (FTIR) revealed that the targeted oligomer was successfully prepared. The oligomer with the number-average molecular weight of 2040 g mol–1 exhibited a narrow molecular weight distribution (PDI = 1.23). CO-SH could be stored at 80 °C for 7 days with only a light C═C conversion (≈6%); hence, the steric effect of the vegetable oil molecule gave the primary biothiol an excellent temporal stability. Furthermore, real-time FTIR results indicated that excellent photopolymerization profiles were obtained, and the final conversions of double bond and thiol were 100% and 77% in the absence of PI, respectively, showing the rapid self-initiated photoactivity. In addition, the self-initiated photopolymerization mechanism of CO-SH was investigated. Finally, the UV-curable films of CO-SH also showed good physical and chemical properties.
Polymeric membranes are in great demand for biofuels, and ultraviolet (UV)-induced crosslinking currently shows a controllable and ultrafast ability for their fabrication, whereas the weak compatibility between the photoinitiator (PI) and polymer remains a great challenge in the large-scale supply of membranes. Herein, we report a polydimethylsiloxane (PDMS) prepolymer simultaneously functionalized with a PI and photocrosslinker, which endows the prepolymer with self-initiation and self-polymerization properties, respectively. The chemically grafted PI shows a stable and homogeneous distribution over 10 days with a superhigh loading (>5 wt%), which provides an extremely high initiation efficiency. Accordingly, the self-initiated/self-polymerized membranes exhibit an excellent comprehensive performance for bioethanol enrichment compared with the state-of-the-art polymeric membranes. Our PI–polymer design provides a general framework for the high-efficiency fabrication of polymeric membranes.
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