油剂对聚丙烯腈原丝预氧化与低温碳化的影响

Effect of Finishes on the Structural Transformation of PAN Precursor Fiber during the Pre-Oxidation and Low-Temperature Carbonization Process

在相同聚合、纺丝工艺条件下制得两种分别上有不同油剂(No.1、No.2)的聚丙烯腈(PAN)原丝,然后在相同工艺条件下依次进行预氧化、低温碳化处理。采用红外光谱和X-射线衍射表征了两种原丝的预氧化结构,采用差示扫描量热仪研究了预氧丝除油前后在低温碳化阶段的热行为,结果表明:采用No.1油剂的PAN原丝预氧化程度较高,表面除油后在低温碳化阶段时质量损失较小,表现出较好的耐热性;但在不除油的情况下,采用耐热性好的No.2油剂的PAN原丝尽管预氧化程度较低,但在低温碳化阶段时质量损失较小,表现出更好的耐热性。与预氧化程度相比,油剂的耐热性对预氧化纤维在低温碳化阶段的热行为影响更大。

Two different finishes named No.1 and No.2 were separately applied to PAN precursor fibers prepared under the same conditions of polymerization, spinning, and then the the fibers were treated in pre-oxidation and carbonization. The structure of the pre-oxidized fibers was characterized by FTIR and XRD. A comparative study on the thermal properties was made by using DSC/TG regarding both theuntreated pre-oxidized fibers and the treated pre-oxidized fibers from which the finish was extracted by using the organic solvent. The results showed that the No.l finish-applied PAN precursor fiber had a higher pre-oxidization degree resulting in a better heat-resistance and less weight-lose after removing finishes during the low-temperature carbonization. Referring to the pristine oxidized fibers, although No.2 finish-applied fiber had a lower oxidization degree, it had a better heat-resistance and less weight-lose because the No.2 finish had much excellent heat-resistance than No.1 finish.