Application of nanomaterials in sizings for glass fibre/polypropylene hybrid yarn spinning

Simultaneous spinning of commingled yarns and their investigation in terms of distribution homogeneity and thermal shrinkage is described in comparison with those intermingled by air jet texturing. Furthermore, the incorporation of various nanofillers into glass fibre (GF) sizings is demonstrated as an approach to achieve nanostructured interfaces and interphases in composites materials. Nanoclay, TiO2 and multiwalled carbon nanotubes (MWNT) were used in the GF sizings. The use of the smallest amounts of different nanofillers affects the GF strength, the fibre-matrix adhesion as well as the mechanical properties of the composites to a varying extent as was evidenced by mechanical testing of the GF and the unidirectional composites. One of the suggested mechanisms of the MWNT in the fibre/matrix interface is the impact on the crystalline morphology of the polymeric matrix. Moreover, fracture mechanisms inherent to MWNT can affect the mechanical performance of the yarns and the composites. Similar to conventional nanocomposites, the dispersion and homogeneous distribution of the nanoparticles is of vital interest if their characteristics as reinforcing material shall be exploited.