Photo and Thermal Cured Silicon-Containing Diethynylbenzene Fibers via Melt Electrospinning with Enhanced Thermal Stability

An inorganic–organic hybrid material, poly(dimethylsilylene ethynylenephenyleneethynylene) (PMSEPE), was synthesized in a mild condition and its microfiber was successfully produced by melt electrospinning. The electrospinning parameters, which affected the morphology and diameter of fibers, were well investigated. To maintain the fiber structure at thermal cured temperature (above melting point), the PMSEPE fibers were enhanced via thiol-yne photo polymerization. Followed by the thermal curing reaction, the heat-resistance and mechanical properties of fibers were enhanced. The mechanism of two-step curing was explored and confirmed by means of Fourier transform infrared, differential scanning calorimetry, and X-ray photoelectron spectroscopy (XPS). Thermaogravimetric analysis and scanning electron microscopy results show that after carbonization at 800 °C, the two-step cured fibers had only a small weight loss (20%) and the fibers can still maintain the original morphology. Moreover, the two-step cured fiber exhibited a high tensile strength (55.4 MPa) and a small elongation at break (0.02%). All the results indicate that the fibers could be applied as fiber-reinforced materials.