Synthesis and Tribological Behavior of Ultra High Molecular Weight Polyethylene (UHMWPE)-Lignin Composites

摘要

In this paper, we report the synthesis and characterization of ultra-high molecular weight polyethylene (UHMWPE)-lignin composites. During this study four different compositions, namely UHMWPE, UHMWPE-13 wt. % lignin, UHMWPE-25 wt. % lignin and UHMWPE-42.5 wt. % lignin were fabricated by hot pressing. Detailed microstructural studies by scanning electron microscopy (SEM) showed that UHMWPE and UHMWPE-13 wt. % lignin had a uniform microstructure, whereas UHMWPE-25 wt. % lignin and UHMWPE-42.5 wt. % lignin samples were riddled with pores. UHMWPE and UHMWPE-13% lignin showed comparable flexural strengths of ~32.2 MPa and ~32.4 MPa, respectively. However, the flexural strength dropped drastically in UHMWPE-25 wt. % lignin and UHMWPE-42.5 wt. % samples to ~13 MPa and ~8 MPa, respectively. The tribology of UHMWPE-lignin composites is governed by the tribofilm formation. All the compositions showed similar μ mean values and the specific wear rates ( WR ) decreased gradually as the concentration of lignin in UHMWPE was increased.