Polyetheretherketone/Carbon Nanotube Composites:Synthesis And Properties

Polyether ether ketone（PEEK）is a thermoplastic polymer resin.Because of its excellent comprehensive properties,it has been used in aerospace,automotive,electronic information,biomedical and other fields.However,under some special conditions,such as when it is used as impact-resistant parts in aerospace（such as wing leading edge）,its tensile strength and modulus do not meet the service conditions.For example,PEEK as an implant material is implanted in the human body for a long time.With the erosion of PEEK by external forces and body fluids,higher requirements are put forward for the matching of mechanical properties with human tissues and surface activity.To further expand the application of PEEK in various fields,researchers have carried out a large number of modification studies.Carbon nanotubes（CNTs）which have been one of the leading materials used in PEEK filling modification research have excellent mechanical properties and surface activity.However,when they are directly physically blended,CNTs tend to aggregate due to their poor interfacial compatibility,which fails to improve the mechanical properties of the composites significantly.In this study,the sulfonated polyether ether ketone（SPEEK）was grafted onto the surface of CNTs to obtain the carbon nanotube compounds（SHCNTs）.Then these compounds were added to the PEEK matrix to prepare the composites.Because SPEEK and PEEK have similar chemical structures.S-HCNTs and PEEK have good interface compatibility to improve the dispersion of S-HCNTs in the matrix PEEK which resulted in excellent mechanical properties.The main contents of this paper include:Firstly,PEEK was sulfonated to obtain SPEEK,and CNTs were aminated to obtain CNTsHDA.Additionally,SPEEK was chemically grafted onto the surface of CNTs by the reaction between amino groups and sulfonic groups to get the graft-modified compound S-HCNTs.The intermediate products and S-HCNTs were characterized by Fourier transform infrared spectroscopy（FTIR）,and X-ray photoelectron spectroscopy（XPS）.The results indicated that CNTs grafted compound S-HCNTs were successfully synthesized,and the structure of CNTs was not damaged during the modification process.It was found that the best inventory ratio of CNTs-HDA to SPEEK was 5:1.Secondly,PEEK/CNTs and PEEK/S-HCNTs composites with different additions were prepared via a hot-press approach,and the thermal and mechanical properties of the two groups of samples were tested.SEM test demonstrated that the carbon nanotubes in PEEK/CNTs composites were seriously agglomerated with the same amount of additives and the modified S-HCNTs exhibited better dispersion in the PEEK matrix.Compared with PEEK/CNTs composites,the PEEK/S-HCNTs composites has a more significant influence on the crystallinity,thermal properties and mechanical properties of PEEK.When the content of S-HCNTs was 5 wt%,the crystallinity,storage modulus,glass transition temperature and tensile strength of the composite reached the maximum level.In particular,its tensile strength and flexural strength respectively increased by 32%and 33% compared with pure PEEK.