木质纤维素在球磨过程中的相变行为

THE POLYMORPHIC TRANSFORMATION OF LIGNOCELLULOSE IN BALL-MILL PROCESSING

用X射线衍射对中国马尾松中的本质纤维素在球磨过程中的降解、解结晶、重结晶和相转变进行了定量的研究。本文的实验证明,球磨木质纤维素有着与球磨纤维素不同的重结晶和相转变行为,木质纤维素中的共存木素对球磨非晶态纤维素向纤维素Ⅱ的转交起着障碍的作用,但对它们向纤维素Ⅰ的重结晶则不存在影响。这个结果支持由Coring和Sarko等先后提出的纤维素Ⅰ向纤维素Ⅱ转变的理论和机理。

To begin aserial studies on the crystalline morphology of lignocel Iulose,the Chinese Southern Pine (Pinus massoniana)was chosen as a sample,and was milled in a vibratory ball mill for periods ranging from 5minuts to 12 hours.Then the milled samples were either recrystallized by wetting in water,orsubjected to a treatment of delignification.And finally,all this samples were investigated with x-ray diffraction. The recrystallization behavior of the milled lignocellulose is found differs from that of milled cellulose.For the samples milled for extreme long,time and recrystallized by wetting in water,the crystallinity no longer decreases with the increasing of milling time,which is what happening.in that of milled cellulose,contrary,it even increases slightly.In addition,it seems that the presence of lignin in lignocellulose tends.to restrict the amorphous cellulose produced by milling to recrystallize into celluloseⅡ, but has no influence on the recrys tallization occuring into celluloseⅠ, These experimental results above are explicable comparing with a mechanism of the conversion of cellu lose Ⅰto CelluloseⅡ, proposed by Revol and Goring early,and by Okano and Srako recently.