Camellia oleifera shells (COS), are the by-product of Camellia oleifera seed oil processing, and possess a high lignin content (38.6%). However, information on the fundamental chemistry of this lignin is limited. Herein, mechanochemical strategies combining ball-milling with mild acetosolv or alkaline treatment are presented to compare the structural evolution of COS lignins. The mechanochemical processes significantly improve the lignin yield, releasing lignins with high molecular weights (M_w ≈ 7000 mol/g). The COS lignins are GS-type lignins, and G units account for 71.9% of MWL. The synergistic combination of ball-milling and acetosolv treatment led to the cleavage of β-O-4 linkages. In contrast, the alkaline lignin fractions retained a large number of β-O-4 linkages (50.67/100 Ar) and a low phenolic OH content (1.56 mmol/g), indicating that the ball-milling process had little effect on the alkaline lignin structures (typical substructures). In summary, understanding the structural conversion and characteristics of lignins during the combined pretreatments of COS would facilitate the optimization of the pretreatment process and the deconstruction of COS.

油茶壳 (COS) 是油茶籽油加工的副产品，木质素含量高 (38.6%)。然而，关于这种木质素的基本化学信息是有限的。在此，提出了将球磨与温和的乙酰溶剂或碱处理相结合的机械化学策略，以比较 COS 木质素的结构演变。机械化学过程显着提高了木质素产量，释放出高分子量的木质素（M _w ≈ 7000 摩尔/克）。COS木质素为GS型木质素，G单元占MWL的71.9%。球磨和乙酰溶剂处理的协同组合导致 β-O-4 键的断裂。相比之下，碱性木质素组分保留了大量的 β-O-4 键 (50.67/100 Ar) 和较低的酚羟基含量 (1.56 mmol/g)，表明球磨过程对碱性木质素几乎没有影响木质素结构（典型的子结构）。总之，了解木质素在 COS 联合预处理过程中的结构转化和特性，将有助于预处理工艺的优化和 COS 的解构。