核磁気共鳴法によるフェノールノボラック樹脂分別物のメチレン結合相対比率の定量(ノート)

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The modes of substitutions of methylene linkages to phenolic nuclei in the fractions of phenol novolac resins fractionated by a methanol-water system was discussed by nuclear magnetic resonance (NMR). The original random and high-ortho novolac resins as samples were prepared by using hydrogen chloride and zinc acetate as catalysts, respectively.<BR>The chemical shifts of 2, 2'-, 2, 4'- and 4, 4'- methylene protons of the fractions were found to be dependent on molecular weights. The chemical shifts of 2, 2'-, 2, 4'- and 4, 4'-methylene protons were 4.30 to 4.40 ppm, 4.17 to 4.20 ppm and 3.83 to 3.86 ppm, respectively, denoting δ values from TMS in <I>d</I>-pyridine at 70°C. The NMR apparatus used was a JNM Model MH-100 spectrometer of Japan Electron Optics Laboratory Co.<BR>Dependence of the proportion of 2, 2'-, 2, 4'- and 4, 4'-methylene linkages on the molecular weights of the fractions was not observed in the high-ortho novolac resins. However, it seemed that the content of 2, 4'-methylene linkage slightly increased with increasing the molecular weights of the fractions of the random novolac resins.
社団法人日本分析化学会の論文