Synthesis of two kinds of β-O-4 lignin model polymer
Lignin model polymer of guaiacyl(G) and hydroxyl-phenyl( H)was prepared through CuBr2 brominated,alkali catalyst oxygen anion nucleophilic addition reaction,using 4-hydroxyl acetophenone and 4-hydroxyl-3-methoxyl acetophenone as initiator, then reduced by NaBH4 The lignin model polymer were charactered by 1H-NMR and 13C-NMR,IR spectra(IR) ,Matrix-Assisted Laser Desorption Ionization-Time of Flight Tandam Mass Spectrometer ( MALDI-TOF-MS ) and Gel Permeation Chromatography ( GPC ). The results indicated that the polymer were linear chain polymer which contained β-O-4 linkages, but not C-y and y-OH. The molecular weight of repeat unit of polymer was 136. 16 n+2. The structure and properties of lignin model polymer were similar with that of separated lignin. Ft could be dissolved in conventional solvent of lignin. Weight-average molar mass of polymers were above 5000 and more similar with that of technical lignin. The dispersion of lignin model polymer ( H-type and G-type) , DPn were 1. 26,1. 76 respectively , The synthesis of lignin model polymer could provided a new experimental method for investigation pyrolysis and depoly-merization of lignin under different thermochemical conditions.
4-hydroxyl acetophenone derivativeβ-O-4 lignin model polymersynthesis
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NSTL
万方数据
维普
