The composite PAN fibers which incorporated with CNTs and Titania were prepared by mean of wet spinning. These fibers were then pre-oxidized with microwave heating in an air atmosphere. A combination of characterizations was carried out to study the impact of nanoparticles fillers on the properties of as-spun fibers and their performance during the microwave pre-oxidation. The addition of an equal amount of fillers made obvious changes in the chemical and crystalline structure, consequently improves the strength, and this could lower the capability to creep over a wide range of temperatures in the subsequent processes. FTIR and NMR analyses results of the pre-oxidized fibers exhibited clear changes in the PAN structure, where the dehydrogenation reaction and the degree of cyclization were investigated. Additional confirmation of the occurrence of cyclization reaction was achieved by XRD and thermal analysis. According to the TGA results, the pre-oxidized CNT1/ Ti-PAN fibers exhibit greater thermal stability suggesting high carbon content and good quality could result in the dependent carbon fibers.

    Abstract
    Graphic abstract
    1 Introduction
    2 Experimental
        2.1 Materials
        2.2 Solutions preparation
        2.3 Fiber spinning
        2.4 Pre-oxidation process
        2.5 Measurements
    3 Results and discussion
        3.1 FTIR analysis
        3.2 Solid-state 13C NMR analysis
        3.3 Elemental analysis
        3.4 XRD analysis
        3.5 Thermal analysis
        3.6 The influence of modification on the mechanical properties
        3.7 SEM observation
    4 Conclusion
    References

• Tienah H. H. Elagib(State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Faculty of Industrial Engineering, University of Gezira)
• Elwathig A. M. Hassan(State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University, Faculty of Industrial Engineering, University of Gezira)
• Baihua Liu(State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University)
• Keqing Han(State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University)
• Muhuo Yu(State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Donghua University)