Mechanical and tribological properties of hybrid fabric-modified polyetherimide composites

Modified polyetherimide (PEI) resins were prepared by a series of phenylethynyl terminated etherimide (PTEI) oligomers with different calculated Mn. Hybrid fabric-modified PEI composites were fabricated by dip-coating and subsequently thermal curing. For comparison, hybrid fabric-unmodified PEI composite was also prepared. Modification of PEI had a great influence on the performances of hybrid fabric composites. Mechanical characterizations indicated that there exhibited a remarkable improvement in the Rockwell hardness and fabric bonding strength. The tribological properties of hybrid fabric composites were investigated by a MPX-2000A friction and wear tester with an end-face contact mode. The best tribological properties of hybrid fabric composites were obtained when modified PEI was prepared by PTEI oligomers with the calculated Mn of 5000 g/mol. The friction and wear mechanisms were explored by a combination of mechanical analyses and scanning electron microscope (SEM) observations of worn surfaces and wear debris. Note that modified PEI afforded excellent interface between fabric and resin in the corresponding fabric composites. This can ensure outstanding mechanical properties and significantly restrain the initiation and growth of cracks on the worn surfaces, thereby improving wear resistance.