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首页> 外文期刊>Holzforschung >Effect of different catalysts on the oxyalkylation of eucalyptus Lignoboost® kraft lignin
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Effect of different catalysts on the oxyalkylation of eucalyptus Lignoboost® kraft lignin

机译：不同催化剂对桉树Lignoboost®Kraftlignin氧化物的影响

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摘要

Lignin obtained by Lignoboost (R) procedure from black liquor after kraft pulping of Eucalyptus globulus wood was characterized and converted into liquid polyols via an innovative and safe procedure using base catalyzed oxyalkylation with propylene carbonate (PC). The effect of four catalysts, Potassium carbonate (K2CO3), 1,8-diazabicyclo [5.4.0] undec-7-ene (DBU), dicyanodiamide (DICY), and 1,4-diazabicyclo [2.2.2] octane (DABCO) was evaluated in terms of lignin polyol yield and weight gain. The ensuing polyols were also characterized by fourier transform infrared (FTIR), H-1 NMR, C-13 NMR, and size exclusion chromatography (SEC) to determine the degree of the substitution (DS), degree of polymerization (DP), and the molecular weight, respectively. Only a minor proportion of PC (ca. 3-15%) was converted to propylene glycol/homooligomers as revealed by high performance liquid chromatography (HPLC). All catalysts promoted preferential derivatization of lignin phenolic OH groups by oxypropyl moieties. The maximum average DP of propylene oxide chains in oxyalkylated Lignoboost (R) kraft lignin (oKL) was 1.85 per one phenylpropane unit (PPU) using DBU. Conversely, the DP of oKL using DICY was very low (0.27/PPU). DICY's catalytic activity seems to be jeopardized due to the formation of unreactive adducts with lignin. The oKL obtained using DBU, DABCO, and K2CO3 have potential to be used as polyols in the production of polyurethanes as the corresponding hydroxyl number (I-OH) is in the range of 198-410 mg KOH g(-1).
机译：通过使用碱催化氧化羰基化与丙烯酸丙烷（PC），通过使用碱催化氧化盐（PC）的创新和安全程序将来自黑液的Lignoboost（R）方法从黑液中获得的Lignin。四种催化剂，碳酸钾（K2CO3），1,8-二氮杂双环[5.4.0] UNDEC-7-烯（DBU），二氰基胺（DICY）和1,4-二氮杂双环[2.2.2]辛烷值（DABCO ）在木质素多元醇产率和体重增加方面进行评估。随后的多元醇还表征，其特征在于傅里叶变换红外（FTIR），H-1 NMR，C-13 NMR和尺寸排阻色谱（SEC），以确定取代度（DS），聚合度（DP）和分子量分别。仅通过高效液相色谱（HPLC）揭示的丙二醇/碘聚物仅较小比例的PC（约3-15％）。所有催化剂均通过氧熟化部分促进木质素酚类OH基团的优先衍生化。使用DBU为每一个苯基丙烷单元（PPU）为1.85，氧化氧化物的木质卵泡（R）牛皮蛋白（OK1）中环氧丙烷链的最大平均DP。相反，使用DITY OKL的DP非常低（0.27 / PPU）。由于与木质素的不可思议的加合物形成，Dicy的催化活性似乎受到危及。使用DBU，DABCO和K 2 CO 3获得的OK1具有在聚氨酯的生产中用作多元醇，因为相应的羟基数（I-OH）在198-410mg KOH G（-1）的范围内。

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