The structural and thermal features of coconut coir pith lignin, isolated by three different extraction protocols incorporating two different energy supply sources, were characterized by different analytical tools. The three different chemical extraction protocols were alkaline - 7.5% (w/v) NaOH, organosolv - 85% (v/v) formic and acetic acids at 7:3 (v/v) ratio and polyethylene glycol (PEG): water ratio at 80:20 wt%. The two sources of energy were thermal or microwave. Raw lignins were modified by epichlorohydrin to enhance reactivity, and the characteristics of raw and modified lignins were comparatively analysed. Using the thermal energy source, the alkaline and organosolv processes obtained the highest and lowest lignin yields of 26.4 ± 1.5 wt% and 3.4 ± 0.2 wt%, respectively, as shown by wet chemical analysis. Specific functional group analysis by Fourier transform infrared spectra (FTIR) revealed that significantly different amounts of hydroxyl and carbonyl groups exist in alkaline, organosolv and PEG lignins. Thermogravimetric analysis (TGA) illustrated that the lowest degradation onset temperature was recorded for organosolv lignin, and the overall order was organosolv < alkaline ≤ PEG (microwave) < PEG (thermal). Irrespective of the extraction protocol, microwave energy provided the highest wt% loss rate, indicating the lowest thermal stability. The derivative temperature difference profiles from the microwave and thermal heating sources for different extraction protocols are discussed in detail. These findings show that lignin extraction from coir pith can be performed efficiently with several protocols and that those methods offer practical value to industry.

通过三种不同的提取方法（结合两种不同的能源），分离出椰壳椰皮木素的结构和热学特征，并用不同的分析工具进行了表征。三种不同的化学提取方案是碱性-7.5％（w / v）NaOH，有机溶剂-85％（v/ v）甲酸和乙酸比例为7：3（v / v），聚乙二醇（PEG）：水比例为80:20 wt％。两种能源是热能或微波。通过表氯醇对粗木质素进行改性以提高反应活性，并比较分析了粗木质素和改性木质素的特性。如湿化学分析所示，使用热能源，碱法和有机溶剂法分别获得了最高的木质素收率和最低的木质素收率，分别为26.4±1.5 wt％和3.4±0.2 wt％。通过傅立叶变换红外光谱（FTIR）进行的特定官能团分析显示，碱性，有机溶剂和PEG木质素中存在大量不同的羟基和羰基。热重分析（TGA）表明，有机溶剂木质素的降解起始温度最低，总体顺序为有机溶剂<碱性≤PEG（微波）<PEG（热）。不管提取方案如何，微波能量提供的wt％损失率最高，表明热稳定性最低。详细讨论了微波和热源在不同提取方案下的导数温差曲线。这些发现表明，用几种方法可以有效地从椰皮中提取木质素，这些方法为工业提供了实用价值。详细讨论了微波和热源在不同提取方案下的导数温差曲线。这些发现表明，用几种方法可以有效地从椰皮中提取木质素，这些方法为工业提供了实用价值。详细讨论了微波和热源在不同提取方案下的导数温差曲线。这些发现表明，用几种方法可以有效地从椰皮中提取木质素，这些方法为工业提供了实用价值。