Rongpeng Liu,Bing Zhang,Liqiang Wan,Farong Huang,Lei Du
The kinetics for the reaction of diazide (4,4′-biphenyl dibenzyl azide) and diyne (dipropargyl bisphenol A) catalyzed by CuBr-PMDETA (N, N, N′, N″, N″-pentamethyldiethylenetriamine) was studied in this paper by means of nuclear magnetic resonance spectra (1H-NMR) and differential scanning calorimetry (DSC). 1H-NMR was carried out to analyze solution polymerizations under different CuBr-PMDETA ratios in DMSO-d6. The results showed that CuBr-PMDETA catalytic system was easy to be oxidation under ambient condition. However, different CuBr-PMDETA ratios influenced the catalytic efficiency and the optimal ratios were found in nitrogen gas. DSC was carried out to analyze bulk polymerizations. The results showed that the apparent activation energy (Eα) calculated by Kissinger's method was 69.2 kJ/mol, which was confirmed by Friedman's method. The two tests indicated that the catalyzed polymerization of diazide and diyne was a second order reaction.
Zhuoxin Wen,Xiaoyue Yang,Meiqi Wang,Jia Yang,Manman Zhao,Zhanxiong Li
In this paper, 2-bromoisobutyryl bromide (BIBB) was used to gain access to the active site of an atom transfer radical polymerization (ATRP) reaction on fiber surface to prepare a Cotton-Br macromolecular initiator. It was then used to trigger the ATRP polymerisation of styrene under the PMDETA/CuBr system. The influence of monomer concentration, bath ratio, and grafting time on the in situ generation of micro- and nanomorphic coatings on fiber surfaces were also investigated. Cotton-PS, a cotton fabric with controllable rough morphology of fiber surface, was obtained through the adjustment of grafting reaction conditions. Energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR) and atomic force microscope (AFM) test proved that grafting reaction was successful. The C-Br on coating surface can condensed with perfluoropolyether carboxylic acid (PFPE-COOH), and the ensuing reaction introduces Diazabicycloundecene (DBU), thereby activating the PFPE-COOH. Under mild reaction conditions, this process produces superhydrophobic cotton fabrics. The effect of different molecular weight PFPE-COOHs on hydrophobicity was also investigated during chemical modification. The contact angle (CA) of modified cotton fabric increased from 144.8 ± 3.6° to 155.2 ± 3.5° after chemical modification with PFPE-COOH, exhibiting superhydrophobicity. The finished fabric showed excellent oil-water separation performance. Subsequent to the completion of 10 cycle tests, its oil-water separation efficiency was maintained at 98.6%.
危险品化学品经营许可证（带存储）