Comparative study on microstructure, mechanical, and tribological property of gamma‐irradiated polytetrafluoroethylene, polyetheretherketone, and polyimide polymers

Abstract

In this paper, three commercial polymers (polytetrafluoroethylene [PTFE], polyetheretherketone [PEEK], and polyimide [PI]) were irradiated by gamma rays in the ambient air. The changes in microstructure, mechanical, and tribological properties of these three polymers after irradiation were investigated comparatively. The results display that both the surface and internal structures of PTFE are degraded due to the irradiation chemical reaction, and the molecular chain scission at the surface is more severe than that at its internal as a result of the involvement of oxygen. The oxidative degradation also plays a dominant role in the PEEK surface, but the molecular chain crosslink is dominant in the PEEK internal. The top layer of PI also shows the characteristics of oxidative irradiation degradation, but its internal exhibits excellent irradiation resistance and no structure change occurs even at irradiation doses up to 20 MGy. The microhardness and scratch resistance of irradiated surfaces for all three polymers decrease but only the scratching damage mode of PTFE changes after irradiation. Friction experiments show that the friction coefficients of PTFE increase but that of PEEK decrease after irradiation. The wear rates on the irradiated surfaces of all three polymers increase compared with the unirradiated samples. Moreover, there is a depth gradient effect on the wear properties of both irradiated PTFE and PEEK polymers. The changes in wear rates of irradiated surfaces are consistent with the structural variations of all three polymers.

Synthesis of Amorphous Poly (aryl ether ketone) Resin and its Anti‐Irradiation Properties under Gamma Ray

“…The slight reduction of O concentration was attributed to the short exposure time in the air environment. The samples are not sufficiently oxidized relative to the original sample surface, resulting in a decrease in oxygen content [28] …”

“…The samples are not sufficiently oxidized relative to the original sample surface, resulting in a decrease in oxygen content. [28] To reveal the possible chemical reaction occurring on three polymers during the gamma irradiation process, the C 1s XPS spectra of the pristine, the irradiated PEKÀ C, PEKÀ P and PEKÀ F were further analyzed. For the PEKÀ C before and after irradiation, the peaks of C 1s can be deconvoluted into four peaks at near 284.8, 286.5, 287.3 and 289 eV, corresponding to CÀ C, CÀ O, C=O and OÀ C=O bonds, respectively.…”

Effects of Electron Beam Irradiation on Mechanical and Tribological Properties of PEEK

“…Numerous researches have examined how PEEK and its composites react to various radiation sources, such as heavy ions [ 12 , 13 , 14 ], gamma rays [ 15 , 16 ], UV radiation [ 17 ], or combined with aging [ 18 ] and electron irradiation [ 19 , 20 ] since the polymer was first commercialized in 1978. These methods are very effective for controlling various properties of materials including polymers.…”

Improving the tribological performance of polyphenylene sulfide by incorporating irradiation treated polytetrafluoroethylene powders

“…32 Conventionally, irradiation treatment technology which bears the advantages of cleanliness and high efficiency has been widely adopted in industrial sectors to modify the properties of polymer substrates, especially in terms of PTFE. [33][34][35][36] Kamga et al 37 prepared polyamide (PA)-based composites which were modified using irradiation treated PTFE. The results indicated that using irradiation treated PTFE as solid lubricant resulted in lower friction coefficient and wear rate.…”