不同工艺制备的聚丙烯腈纤维的耐碱特性研究

Alkaline resistance of polyacrylonitrile fibers from different technology processes

模拟水泥混凝土的施工条件,试验测定了3种不同工艺制备的聚丙烯腈(PAN)纤维在碱性条件下的结构和性能变化。红外光谱(FT-IR)测试结果表明,在碱性介质的作用下PAN纤维发生一定程度的水解,广角X-射线散射(WAXS)分析表明,在碱性条件下PAN纤维的结晶度、晶粒尺寸、晶区取向因子均出现一定程度的下降。其中以碳纤维原丝生产工艺(PAN-1)制备的聚丙烯腈纤维分子质量最高,共聚单体含量最低,结晶度、取向度最高,耐碱腐蚀能力最好,强力保持率明显高于常规干法纺丝(PAN-2)和常规湿法纺丝(PAN-3)制备的PAN纤维,有潜力作为水泥混凝土防裂增强材料使用。

Three different kinds of polyacrylonitrile(PAN) fibers were chosen to investigate their structure and properties changes during the alkaline treatment which were related to the cement concrete application conditions. The FT-IR and WAXS results showed that all the samples treated in alkaline solution were hydrolyzed to some ex-tent and the crystallinity, crystal sizes as well as crystalline orientation had a certain decrease.In the alkaline treat-ment experiment, the strength retention of PAN-1 prepared by the carbon fiber precursor technology was higher than those of conventional dry spinning PAN fibers(PAN-2) and conventional wet spinning PAN fibers(PAN-3), show-ing the best alkaline resistant.This phenomenon was closely associated with the structure of PAN-1 fibers with high-er molecular weight, larger crystallinity, higher degree of crystalline orientation, and lower copolymer content.Ac-cording to the alkaline resistant characteristics of the three fibers, it suggests that PAN-1 has the potential to be used as reinforcement material in cement.