Morphological structures and tribological performance of unsaturated polyester based untreated/silane-treated halloysite nanotubes

In this study, pristine halloysite nanotubes (HNT) and silane-treated halloysite (s-HNT) particles were incorporated into highly crosslink unsaturated polyester (UPE) to explore the morphological structure and tribological performance of UPE-HNT nanocomposite. Wear resistance of cured UPE/HNT and UPE/s-HNT nanocomposites were systematically evaluated using block-on-ring (BOR) configuration against stainless steel counterpart under a certain dry sliding conditions. TEM micrographs revealed a uniform morphological dispersion of halloysite particles in the UPE matrix. Both pristine and silane-treated HNT particles induced a modest decrease in a specific wear rate and coefficient of friction of nanocomposites. There was a pronounce reduction in the specific wear rate of the polyester composites at more than 5 wt.% of halloysite. However, the addition of silane exhibited insignificant results especially at higher percentages of HNT. The investigation of worn surface morphology and wear mechanism of materials by using SEM is also discussed.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Homogenous structures of UPE-HNT/s-HNT are obtained from TEM. ► A modest decrease in the specific wear rate of UPE nanocomposites due to the halloysite effect. ► Two wear mechanisms are observed, two-abrasion and three-abrasion with the untreated HNT. ► The adhesive wear mechanism is detected within UPE/silane-treated HNT nanocomposites. ► Higher additions of halloysite particles reduce material removal loss without sacrifice Tg.