升温速率对聚酰胺酸/聚丙烯腈基碳纤维结构的影响  

Effects of Heating Rate on Structure of the Carbon Fibers Derived from Poly( amic acid)/Polyacrylonitrile Blend

作　　者：刘威威[1] 张梦颖[1] 曹维宇[1] 王子琦[1] 李昂[1] 牛鸿庆[1] 武德珍[1] 

机构地区：[1]化工资源有效利用国家重点实验室北京化工大学材料科学与工程学院,北京100029

出　　处：《高分子学报》2016年第6期728-733,共6页Acta Polymerica Sinica

基　　金：高等学校博士学科点专项科研基金(基金号20130010130001);国家自然科学基金(基金号51373008);北京市科技计划(项目号Z141100004214005)资助项目

摘　　要：采用聚酰胺酸/聚丙烯腈(PAA/PAN)为原材料制备共混前驱体,经热处理完成PAA的亚胺化和PAN的预氧化,再以一定的升温速率升温至1200℃,得到新型共混基碳纤维,采用SEM、Raman、XRD、EA等方法研究了不同的升温速率对PAA/PAN基碳纤维碳化结构的影响.结果表明,碳纤维表面沿纤维轴方向有少量的沟槽,这是湿法纺丝工艺造成的.1200℃的高温处理使碳元素富集,最终制得碳含量高于92%的碳纤维.随着碳化升温速率的增大,碳收率也在增大,最大碳收率达52.36%.碳纤维的石墨化程度和微晶尺寸随着碳化升温速率的提高均呈现先增大后减小的趋势,当升温速率为8 K/min时,所得纤维的碳化结构最为理想,微晶堆叠厚度达到1.445 nm,g(A_G/A_D)值达到0.52,此条件下,纤维的碳元素含量也达到了94.13%,电阻率最小.A series of poly（ amic acid）/polyacrylonitrile（ PAA/PAN） blend fibers were prepared,and then stabilized in air in a temperature range of 200- 280 ℃. After stabilization,the fibers were carbonized in nitrogen up to 1200 ℃ at different heating rates. The effects of heating rate on the chemical composition and structure of the resultant carbon fibers were investigated. Carbon fibers were characterized by scanning electron microscopy（ SEM）,laser Raman spectroscopy,X-ray diffraction（ XRD）,carbonization yield and elemental analysis（ EA）. The results showed that the heat treatment expelled impurites as volatile by-products leading to an increase of carbon content,which was more than 92% when the carbonization temperature was 1200 ℃.Longitudinal striations along the fiber axis were revealed for all the carbon fibers which were attributed to the wet spinning process. The carbonization yield increased with the increasing heating rate and the hightest yield was 52. 36%. As the heating rate increased,the degree of graphitization and crystallite size increased first and then decreased. The carbon fiber prepared at a heating rate of 8 K/min was found to be optimal in terms of the low electrical resistivity and high graphitization parameters with Lcvalue of 1. 445 nm as well as g value of0. 52.

关 键 词：PAA/PAN共混纤维 PAA/PAN基碳纤维 升温速率 结构 

分 类 号：TQ342.742[化学工程—化纤工业]