Preliminary exploration of processability and self-lubricating properties of polythioetherimides/PEEK blends and their composites

Abstract

Abstract Polythioetherimides (STPI) were first synthesized from 3- and 4-chlorophthalic anhydrides, and 4,4’-oxydianline and 1,3-bis(4-aminophenoxy) benzene by a two-step poly- condensation procedure via their soluble poly (amic acid) precursors. Then a series of isomeric polythioetherimides/polyetheretherketone (STPI/PEEK) blends samples with compositions (wt%) of 30/70, 40/60 and 50/50 were prepared and characterized. The structure characterization of STPI demonstrated by FTIR, Raman and elemental analysis show that there are little S-S bonds of the copolythioetherimides chains. Thermal, rheological, ultrasonic nondestructive testing technique, mechanical measurements and dynamic thermomechanical analysis were conducted to process and assess the morphology and mechanical properties of the STPI/PEEK blends, and 30/70 weight composition of STPI/PEEK was preferred. There are few voids or air gaps in the molding samples. The samples of STPI/PEEK-30/70 show two relaxations at 164.2 °C and 243.5 °C, an average tensile modulus of 1.264 GPa, an average bending elastic modulus of 2.061 GPa and a bending strength of 78.3 MPa. Finally, the friction-wear characteristics of STPI/PEEK composites with solid lubricants such as graphite, MoS2 and PTFE were investigated, indicating a promising way to develop a STPI-based thermoplastic for tribological applications.