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1575592654鐵蟲 (小有名氣)
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[求助]
如何根據(jù)聚乙烯核磁氫譜計(jì)算其支化度 已有1人參與
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根據(jù)得到的氫譜結(jié)果,在0.51,0.91以及1.33處有明顯的峰,所用試劑為氘代四氯乙烷,所以怎么根據(jù)這三個(gè)峰計(jì)算其支化度。 發(fā)自小木蟲Android客戶端 |
專家顧問(wèn) (知名作家)
從事NMR和有機(jī)化合物結(jié)構(gòu)鑒定
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專家經(jīng)驗(yàn): +1121 |
專家顧問(wèn) (知名作家)
從事NMR和有機(jī)化合物結(jié)構(gòu)鑒定
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專家經(jīng)驗(yàn): +1121 |
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Analysis of Chain Branch of Polyolefins by a New Proton NMR Approach 原文直接下載地址: https://pubs.acs.org/doi/pdf/10.1021/acs.analchem.5b04357 |
專家顧問(wèn) (知名作家)
從事NMR和有機(jī)化合物結(jié)構(gòu)鑒定
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專家經(jīng)驗(yàn): +1121 |
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上面文章的摘要: ABSTRACT: The crystallinity of polyethylene, which significantly affects the properties of the polymer, is quite sensitive to the concentration of its branches. Thus, it is necessary to estimate branch concentration with reasonable accuracy. Currently, 13C NMR and gel permeation chromatography−Fourier transform infrared spectroscopy are widely-used analysis methods for the analysis of branch concentration. Despite several advantages, these methods sometimes have limitations. For instance, the preparation of samples for 13C- NMR is tedious because high-concentration samples are required and the time for analysis is greater than 12 h. To more efficiently estimate the branch concentration of polyethylene, we developed a new highfield 1 H NMR method with an improved peak resolution by employing (1) homonuclear decoupling and (2) 2D heteronuclear correlation. The new method was observed to significantly reduce the experimental time to ∼30 min; furthermore, sample preparation was relatively simple because the method did not require high-concentration samples. |
專家顧問(wèn) (知名作家)
從事NMR和有機(jī)化合物結(jié)構(gòu)鑒定
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專家經(jīng)驗(yàn): +1121 |
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