Hybrid Filling of Polyethylene Terephthalate with Multi-Walled Carbon Nanotubes and Short Glass Fibers

The effect of hybrid filling of polyethylene terephthalate with short glass fibers in amount from 15 to 60 wt % and multi-walled carbon nanotubes in amount of 0.5 and 1.6 wt % on the structure, static and dynamic mechanical properties of composites produced by blending in a melt by the method of reactive extrusion was studied. It was shown that nanotubes initiate heterophase crystallization of the polymer matrix, which improves the transfer of stresses to the nanofiller and makes the main contribution to the reinforcing of both nano- and hybrid-filled composites. The elastic moduli of cast specimens increase upon stretching by 41–54% for nanocomposites and by 20–30% for hybrid-filled composites, and upon bending, by 5–18 and 16–21% compared to the initial and glass-filled polymer, respectively. It was demonstrated that the magnitude of the reinforcing effect is related to the orientation of the nano- and micro-filler and depends on the specimen production technology and on the test method.