聚丙烯腈原丝取向结构和力学性能研究

Study on orientation structure and mechanical properties of polyacrylonitrile precursor

以两段拉伸法制备聚丙烯腈(PAN)原丝,以广角X射线衍射方法研究其微观取向结构,单纤维拉伸实验测得原丝的力学性能,声速法测定其取向系数和模量。结果表明,随着拉伸比的增加,原丝中分子链取向增加,其杨氏模量和断裂强度也随之提高,而断裂伸长率则下降。不同拉伸比的PAN原丝取向系数与Crawford和Kolsky取向模型的理论曲线比较吻合。

Polyacrylonitrile (PAN) precursor was prepared by two-stage stretching method. The orientation microstructure of PAN precursor was studied by wide angle X-ray diffraction , the mechanical properties by single fiber tensile test, and the orientation factor and modulus by sonic velocity method. The results showed that the orientation degree of PAN precursor's molecular chain as well as Young's modulus and breaking strength was increased with the increase of draw ratio, but the elongation at break was decreased. The orientation factor of PAN precursor drawn at different ratios coincided with the theoretical curves of Crawford and Kolsky orientation model.