摘要
分别采用扫描电镜（SEM）、广角X-ray衍射（WAXD）和小角X-ray散射（SAXS）研究分析了经含硫酸和尿素催化剂催化处理的Lyocell纤维在热解过程中结构、性能的变化。发现在低温热解前阶段（〈200℃）随着处理温度的升高其密度增大，高于200℃后密度有所下降。纤维强度则表现出先下降后升高的变化规律，并在150℃-200℃温度区存在一个“零强度点”。在此过程中纤维聚合度也发生了类似强度的变化。同时，纤维结晶结构由纤维素Ⅱ型向炭纤维的二维乱层石墨结构转化。
Changes in the structure and mechanical properties during the conversion of lyocell precursors to carbon fibers were investigated by scanning electron microscopy, wide angle X-ray diffraction and small angle X-ray scattering when they were treated with a catalyst containing sulfuric acid and carbamide. It was found that the density of fibers first increased with temperature, then decreased when the temperature exceeded 200 ℃. The strength decreased gradually and was close to zero between 150 ℃ and 200℃, but then increased with increasing temperature. The degree of polymerization showed similar changes to the strength changes during pyrolysis. The crystalline structure of the cellulose Ⅱ crystals in lyocell fibers was converted to a 2D turbostratic carbon structure.
出处
《新型炭材料》
SCIE
EI
CAS
CSCD
北大核心
2007年第1期47-52,共6页
New Carbon Materials
基金
国家自然科学基金(20074005)~~
