离心工艺对溶解浆角质化特征的影响

The Influence of Centrifugation Techniques on the Cuticularization Features of Dissolving Pulp

离心分离是借助离心力,使比重不同的物质进行分离的方法,因具有高效、易操作等优势,成为木质纤维研究中组分分离的常用方法。基于此,围绕离心对溶解浆纤维角质化特性的影响展开研究,探讨了离心时间对溶解浆纤维特性及其角质化特性(保水值、孔隙特性、结晶度和微观形貌)的影响,发现离心过程对纤维特性的影响是多维度的。随离心时间的增加,当7000 g离心力在离心20 min时,纤维保水值78.4%、平均孔径15.79 nm、结晶度81.95%,纤维性能等指标达到最高,纤维表面细小纤维基本消失;离心30 min时,纤维杨氏模量1.63 GPa、硬度137.33 MPa,力学指标达到最高。样品经过干燥后,达到一定离心时间的溶解浆纤维的保水值、孔隙特性、结晶度和微观形貌等变化不大,但发现离心作用可能促进纤维再结晶,但是降低了角质化程度。

Centrifugation is a method using the centrifugal force to separate contained materials of different specific gravities,it is highly effective and conductible,and is widely utilized in the fractionation of xylem fibers in scientific research.This paper researches the impact of centrifugation on cuticularization features of dissolving pulp fiber,discusses the effects of centrifugation time in the pulp’s fiber and cuticularization features including water retention value,pore characteristics,crystallinity,and microstructure.The research shows that the influence of the centrifugation process on fiber features is multi-dimensional.With 7000g centrifugal force and at the time of 20 minutes,the water retention value,average pore size and crystallinity of the fibers reach their peaks,at 78.4%,15.79nm and 81.95%respectively,and fine fibers on the surface have almost disappeared.At the time of 30 minutes,the Young's modulus and hardness of the fibers reach their maximums,at 1.63 GPa and 137.33 MPa respectively.After the drying process,the fiber samples show negligible changes of their water retention value,pore characteristics,crystallinity,and microstructure,however,it is found that centrifugation may trigger the fiber to re-crystalize,but decrease its cuticularized level.