An investigation on tribological properties and mechanical properties of UHMWPE/polycrystalline mullite fiber

In order to improve the wear-resistant properties of polymer composites, a common approach is to introduce high-strength or lubricating components in composites, but the mechanical properties of composites are generally significantly reduced. It is still a challenge to obtain excellent wear resistance as well as good mechanical properties. In this work, a new ultrahigh molecular polyethylene (UHMWPE)/polycrystalline mullite fiber (PMF) composite was developed to simultaneously improve the tribological properties and the mechanical properties. The wear rate ( K 0 ) of UHMWPE/PMF reduced drastically [≈10 –5 mm 3 /( N · m )] to about 2.5% of K 0 of original UHMWPE. And the tensile strength and the elongation at break of UHMWPE/PMF remained at 97.0% and 90.0% of pure UHMWPE, respectively. These improvements are related to the higher crystallinity of UHMWPE/PMF (UHMWPE/PMF: 49.2%; UHMWPE: 41.2%), the larger crystallite sizes (UHMWPE/PMF: 21.0 nm; UHMWPE: 12.0 nm), and the high hardness and excellent mechanical strength of PMF. The simple processing of UHMWPE/PMF composites by adding PMF to increase the tribological properties is low cost and attractive, which has a great potential application in the fabrication of highly wear-resistant materials.