The potential for ultrasound to improve nanoparticle dispersion and increase flame resistance in fibre-forming polymers

Clear evidence of improved dispersion after ultrasound treatment has been shown using image processing software of SEM-EDS data for PP samples and increased intercalation in PP and exfoliation of clays in both PP and PA6 demonstrated by TEM. Increased ease of extrusion into filaments was also noted. For PP formulations, ultrasonification reduced fabric burning rates and drip formation. In PA6, the only positive effects were seen for the PA6/Cloisite 25A/aluminium phosphinate formulation which showed some evidence of synergy and ultrasound increased the LOI of polymer strands from 21.1 to 23.3 vol%. Fabric burning behaviour was more mixed with no clear cut advantages of ultrasound being apparent for PA6.