UHMWPE Modified by Halogenating Reagents: Study on the Improvement of Hydrophilicity and Tribological Properties

Abstract

Three groups of ultra-high-molecular-weight polyethylene (UHMWPE) with optimum hydrophilicity were obtained by halogenation modification. They were immersed in a 15% KBr solution for 30 h, a 10% NH₄Cl solution for 60 h, or a 15% NH₄Cl solution for 60 h. The mechanism of hydrophilicity enhancement by halogenation modification was investigated by combining surface morphologies and energy spectrum analysis. Friction and wear tests were carried out to measure the friction coefficients of modified UHMWPE under different test conditions, and the wear volume and morphologies of the worn surfaces were studied to explore the friction and wear mechanism. The results showed that the best tribological properties were obtained when immersed in the 15% KBr solution for 30 h. Furthermore, the synergistic optimization effect of hydrophilicity enhancement on tribological properties was explained by the lubrication mechanism, as well as the influence of interfacial properties change on the wear mechanism. This study provides an experimental and theoretical basis for using halogenated UHMWPE.

Keywords:

• UHMWPE
• halogenation modification
• hydrophilicity
• tribological properties

Acknowledgement

We thank LetPub (www.letpub.com) for its linguistic assistance during the preparation of this artcle.

Additional information

Funding

The authors are grateful for research support from the Natural Science Foundation of China (Nos. 51575289 and 51705270), National Postdoctoral Program for Innovative Talents (CN, Nos. BX20190114), Shandong Provincial Key Research and Development Program (CN, Nos. 2019GHY112068), and Natural Science Foundation of Shandong Province (CN, Nos. ZR2019PEE028).