PEEK composite materials have their own outstanding performance characteristics. For instance, PEEK carbon fiber reinforced composite material has the characteristics of high strength, high modulus, and wear resistance, making it suitable for use in bearing supports, to name a few. PEEK glass fiber reinforced composite material, on the other hand, boasts high insulation and temperature resistance.
For example, in the aerospace industry, engine controller casings and electrical connectors use the carbon fiber reinforced PEEK composite material, achieving functions such as weight reduction, insulation, electromagnetic shielding, and low residual magnetism. High-temperature insulating glass fiber PEEK composite material is used to manufacture brush connection rings with insulation resistance greater than 25MΩ at 300℃. PEEK carbon fiber material or wear-resistant composite material is used to manufacture various specifications of bearing retainers, gaskets, standard parts, and camera mirror frames, achieving weight reduction and oil-free lubrication. In the weapons industry, various lightweight, high-temperature-resistant, self-lubricating, and heat-insulating components such as bearing retainers, planet structural rollers, missile attitude control frames, antenna covers, and cover plates are made of the PEEK composite material to meet the requirements of lightweight and functionality. In the nuclear industry, PEEK composite material is used for large-sized sealing coils, storage cover materials, winding wires, lifting coil and mobile coil skeletons, etc., satisfying the requirements of radiation resistance and high-temperature resistance.
Polymer materials will produce free radicals after irradiation. Radiation-induced polymer reactions such as oxidation, cleavage, cross-linking, and grafting all come from the production of free radicals. The study of free radicals belongs to the microscopic realm. The primary and secondary reactions of free radicals lead to various results, which are manifested as changes in the physical and chemical properties of materials. Therefore, studying the production and evolution of free radicals is an important component of the study of the irradiation effect of polymer materials. PEEK materials have high tolerance to nuclear radiation (α rays/helium nuclei, β rays/electrons, γ rays/high eV electromagnetic waves), and high-energy radiation often leads to a decrease in plastic elongation and an increase in brittleness.
The following are the basic conclusions:
High-energy electron irradiation mainly acts on the amorphous state, and it can induce cross-linking of the amorphous state. The main manifestations are the increase in glass transition temperature (Tg), the decrease in melting point (Tm), and the decrease in decomposition temperature (Td).
When the dosage of high-energy electron irradiation reaches 180MGy, the tensile performance is almost unchanged, but slight decrease is observed when irradiated at 140℃ with a dosage of 120MGy.
Positive ions cause benzene rings to degrade while double bonds increase, but the mechanical properties remain almost unchanged, as positive ions only act on the surface.
Because PEEK has a high proportion of benzene rings and lacks radiation-sensitive fatty chains, it can withstand gamma radiation of MGy level.