Polyetheretherketone (PEEK) is a semi-crystalline, thermoplastic special engineering plastic developed by the British Imperial Chemical Industry Company (ICI) in 1978. Because PEEK has excellent comprehensive properties such as high temperature resistance, self-lubrication, corrosion resistance, flame resistance, hydrolysis resistance, abrasion resistance and fatigue resistance, it was initially used in the field of national defense and military, and gradually expanded to civilian use. Fields, including industrial manufacturing, aerospace, automotive industry, electronics, electrical and medical equipment. With the continuous improvement of PEEK synthesis and processing technology, its high-performance materials obtained through chemical modification, blending, and composite filling have expanded its application fields. PEEK is suitable for various processing methods such as injection molding, extrusion molding, compression molding, and melt spinning. In recent years, the combination of PEEK resin and advanced manufacturing technologies such as 3D printing has made it new in the medical field such as medical implants. Development direction.
Initial incubation period (1978-1992):
British ICI developed PEEK and its glass fiber and carbon fiber reinforced products, applied for a patent and industrialized it, with a capacity of 1,000 tons per year, which is mainly used in the field of defense and military industry.
Monopoly development and disintegration (1993-2004):
The British company Victrex acquired the PEEK business from ICI, presenting a monopoly development trend and continuously expanding the production scale. In 2003, the production capacity increased to 2800 tons / year, and the application field also expanded from the original military to industrial and biomedical, etc Civilian domain.
Because PEEK is mostly used in the military field, Wiggs imposed a technical blockade on it. With the strong support of China's policies, the team of Professor Wu Zhongwen of Jilin University independently developed the patented PEEK technology with independent intellectual property rights, and established Jida High-tech Materials Co., Ltd. and put it into production. Jida Hi-Tech became the first company to break the Wiggs monopoly.
Comprehensive development stage (2005-present):
In 2005, Evonik acquired Jida Hi-tech, and Solvay acquired the PEEK business in India's Garda. After 2009, the National Polymer Research Institute of China joined a number of material group companies to start technical research into this field. PEEK has entered an all-round development stage, and its performance has reached the international advanced level. In addition, PEEK's modified compounding and processing technology has gradually developed, and its application fields have also been continuously expanded.
Production and processing technology
(A) mainstream synthesis methods
The existing PEEK synthesis production process routes are mainly two categories: nucleophilic substitution chemical reaction and electrophilic substitution chemical reaction. The electrophilic process is prepared by a low temperature reaction using diphenyl ether and isophthaloyl chloride as raw materials. Its advantages are mild conditions and convenient source of raw materials, but there are many side reactions such as polymer branching and crosslinking. At present, the main industrialization in the world is the first type of nucleophilic process.
The basic idea of the nucleophilic process is to use 4,4-difluorobenzophenone and hydroquinone as raw materials, in the presence of anhydrous sodium carbonate, diphenylsulfone as a solvent, and nitrogen protection to gradually increase the temperature. Condensation to a temperature close to the melting point of the polymer (320 ° C) results in a high molecular weight PEEK. The advantage of this process is that side reactions such as branching and cross-linking of the polymer are easier to control. In the process, no metal-based catalysts, stabilizers and additives are used, and high-purity PEEK powder can be produced. However, this reaction path has the disadvantages of harsh reaction conditions, complex synthetic processes, expensive monomers, and high costs.
Over the years, all mainstream manufacturers have carried out further R & D and improvement on the basic ideas of nucleophilic processes, overcoming shortcomings, reducing costs, and forming their own core process routes. This is also the core value technology of the PEEK synthesis industry.
(Two) processing and modification technology
PEEK, as a representative of thermoplastic engineering plastics, has the characteristics of easy processing, and is suitable for conventional plastic processing and molding methods including injection molding, extrusion molding, compression molding, and melt spinning. In recent years, with the continuous development of 3D printing technology, PEEK, as a representative of 3D printing polymer materials, has expanded its application in the field of medical devices, especially medical implants with complex morphological structures.
With the development of processing technology, along with the increase in market requirements for material properties, the modification and compounding of PEEK has become a hot spot in the industry in recent years. In addition to chemical modification by changing the composition and / or proportion of the polymer main chain during the polymerization stage, common industrial performance improvement methods include surface modification, blending modification, and composite filling enhancement. Improve the forming and processing performance of PEEK.
Main application areas
PEEK has excellent comprehensive properties and can replace traditional materials such as metals and ceramics in many special fields. PEEK has applications in machinery manufacturing, aerospace, automotive industry, medical, electronic and electrical, pharmaceutical and food processing industries. Among them, the transportation industry (including automotive and aviation), mechanical industry and electronic and electrical industry account for the highest proportion.
Future trends
After more than 40 years of application development, PEEK's product models, participating companies and application fields have been continuously expanding to maintain a high industry growth rate. However, due to its higher price, it has less market share in special engineering plastics. The mainstream European and American companies have been combining mergers and acquisitions and independent development (or cooperative development) for many years, relying on expanding production scale to produce scale effects, actively developing modified and composite new products, and continuously expanding the scope of application through cooperation in downstream industries.
Although our country has independent research and development technology of PEEK synthesis, and to some extent, it solves the problem of excessive cost of PEEK raw materials. However, the development of China's PEEK industry chain is still far from that of developed countries. Especially in the expansion of high value-added downstream applications, it is difficult to occupy an advantage due to the limitation of the overall industrial manufacturing capacity. With the development of China's large aircraft, rail passenger cars, automotive industry, medical and national defense industry, the demand for special engineering plastics represented by PEEK is also increasing, especially in terms of enhancing the production and processing capabilities of high-performance products.