At present, although substantial progress has been made in the development of high-performance polymer composite materials in China, the industrialization process of high-performance fiber reinforcement, resin matrix and composite material preparation is relatively slow, and there is still a certain gap between some areas and the world’s material powers. . The development of China's high-performance polymer composite materials is as follows.
(1) The development of high performance fiber has its own characteristics
1. The carbon fiber field has initially formed a R&D and production platform, and is developing rapidly in the direction of high performance and low cost
Carbon fiber is a type of inorganic fibrous material with a carbon content of more than 90%. Among them, polyacrylonitrile-based carbon fiber prepared with polyacrylonitrile (PAN) fiber as a precursor is the most important. Its preparation process mainly includes acrylonitrile (AN) Preparation of polymer solution, preparation of PAN precursor, PAN fiber pre-oxidation, PAN pre-oxidation fiber carbonization and surface treatment for composite with resin, if high modulus carbon fiber is prepared, high temperature graphitization process is required. The production process of PAN-based carbon fiber is shown in Figure 1. With the support of the National Technology and Industrialization Demonstration Program, after more than 10 years of collaborative research, China's high-performance carbon fiber preparation and application technology has made major breakthroughs.
(1) Preliminary establishment of high-performance carbon fiber technology and product system, and continuous improvement of technical level
At present, China's domestically produced carbon fiber has initially realized the industrialized scale production of T300 and T700 carbon fibers. Specifically, the performance of T300-grade carbon fiber has basically reached the international level, and its application in the defense field is gradually mature, and its application in the civilian field is still to be explored; T700-grade and T800-grade high-performance carbon fibers have broken through the dry-jet wet spinning process and achieved industrialization Production; Innovatively developed a wet spinning T700-grade carbon fiber preparation process, and related products have been used in the aviation field; under laboratory conditions, T1100-grade high-performance carbon fiber has broken through the key preparation technology. In the field of high modulus, high strength and high modulus carbon fiber, M40 grade high modulus carbon fiber has realized small batch production, with a production capacity of about 300kg/a, and is applied to multiple satellite models; M40J grade high strength and high modulus carbon fiber has completed engineering development , Is undergoing application assessment; M55J high-strength high-modulus carbon fiber is still in the engineering development stage, and higher performance carbon fiber varieties are still in the key technology research and development stage.
(2) A group of carbon fiber production enterprises and R&D platforms have been established, and the domestic carbon fiber industry pattern has basically taken shape
In terms of carbon fiber production enterprises, there are more than 20 carbon fiber enterprises in China, mainly located in Shandong, Jiangsu, Hebei and Jilin. The industrial structure of domestic carbon fiber in China has basically taken shape. Six companies represented by WHTZ Fiber Technology Group, JSHS Carbon Fiber Technology Group, JSZF Carbon Fiber Technology Group, JSKD Carbon Fiber Technology Co., Ltd., JLJG Carbon Fiber Co., Ltd., and SHSH Chemical Technology Group have built more than 10 single-line production capacity of 1,000 tons. In addition, 18 other companies have built production lines with a capacity of tens to hundreds of tons. At the same time, the acrylic fiber industry-based high-strength large-tow carbon fiber precursor technology has made breakthroughs. JLTG Carbon Fiber Technology Co., Ltd. has built a production capacity of 1.5×104t/ A's raw silk production line. In 2019, China's theoretical carbon fiber production capacity reached 2.6×104t/a, and the effective production capacity was about 1.5×104t/a. The T300/T700 grade carbon fiber produced basically meets the application needs of the defense field.
In terms of platform construction, China has established many carbon fiber science and technology research units to support the localized development of the carbon fiber industry, namely 1 national carbon fiber engineering technology research center, 2 carbon fiber preparation technology national engineering laboratories, and 2 carbon fiber composite materials national engineering Laboratory, many national key laboratories.
2. The industrialization of para-aramid is successful, and there is still a gap compared with the international advanced level
Para-aramid is an important member of the para-aromatic polyamide fiber family. The polymer is prepared by polycondensation of terephthaloyl chloride and p-phenylenediamine, which is then prepared by solution spinning Aramid products obtained. The total international production capacity of para-aramid is about 7.6×104t/a, and the operating rate is about 70% to 80%. At present, 8 companies in China have built para-aramid fiber production equipment, with a production capacity of more than 7×103t/a. Generally speaking, the industrialization level of China's para-aramid fiber still lags behind the advanced level abroad, and a strong competition pattern has not yet been formed in terms of industrial scale and application.
In terms of platform construction, China has established a number of national and local R&D and technology platforms for aramid fiber. For example, Donghua University is the supporting unit of the State Key Laboratory of Fiber Material Modification, South China University of Technology is the supporting unit of the State Key Laboratory of Pulp and Paper Engineering, YTTH High Performance Materials Technology Group is the supporting unit of the National Aramid Engineering Center, and ZGLX Chemical Research Institute Co., Ltd. is a supporting unit for the research and development of multi-variety, small-batch military materials such as fiber and other polymer materials.
3. Glass fiber production capacity ranks first in the world, maintaining a slow expansion
Glass fiber is an excellent functional material and structural material. In 2016, China's glass fiber production capacity was approximately 3.8×106t/a, accounting for 60% of the global total production capacity. From 2017 to 2019, the average annual compound growth rate of China's glass fiber production capacity was 6.65%, which was much higher than the global average annual compound growth rate of 1.70%. The annual output of glass fiber in China increased from 9.5×105t in 2005 to 3.62×106t in 2016, and the compound annual growth rate of output reached 12%. Since the "13th Five-Year Plan", the production capacity of glass fiber has maintained a low-speed expansion, and the newly increased production capacity is mainly concentrated in a few companies. The Technology Group put into production a cold repair line.