High Temperature Resistant Engineering Plastic
High temperature engineering plastics are engineering plastics that retain high mechanical properties under high temperature conditions. This property is generally caused by its own special structure. With the continuous development of electronic equipment, the application of high temperature engineering plastics in this field has been expanding and becoming the material of choice in the field of electronic equipment.
Research team from Dalian University of Technology, Polymer Materials Department, Liaoning Province High Performance Resin Engineering Technology Research Center. From the point of view of molecular design, three kinds of high temperature resistant and soluble block copolymers PPENK-b-PEEKK with different block lengths were designed and synthesized. The phthalazinone biphenyl structure polyaryletherketone PPENK segment was successfully combined with a structurally regular PEEKK segment.
The hydroxyl terminated polyetheretherketoneketone (PEEKK-OH) oligomer was synthesized by solution polymerization method. The polymerization process was optimized by orthogonal experiment and the optimal synthesis conditions were obtained. Then, PPENK-b-PEEKK block copolymer was synthesized by one-step stepwise addition. All three copolymers have a crystalline structure with only one glass transition temperature (Tg) (higher than the Tg of PEEKK), and the presence of a melting point, which has potential thermoforming properties. The Td5% and Td10% of the three copolymers were 491-510 and 523-530 °C, respectively. The charcoal at 800 ° C is 63% to 65%, and the copolymer has excellent thermal stability.
The Institute of Chemistry, Chinese Academy of Sciences combines a high temperature resistant polyimide matrix resin solution with a certain proportion of chopped fibers (carbon fiber, glass fiber or aramid fiber) or functional filler (polytetrafluoroethylene, graphite or molybdenum disulfide). And heat-treated to form a B-stage resin fiber molding compound.
A super engineering plastic material having a dense texture and a smooth surface obtained by placing a molding compound into a mold by a high temperature reaction molding process. It can be used for a long time at a high temperature of 300 ° C or higher, and has excellent mechanical properties at both room temperature and high temperature. High temperature resistant polyimide super engineering plastics, including HTPI-1400, HTPI-1500, HTPI-1600 and other three main series products. According to the use temperature, it can be roughly divided into two categories: the long-term use temperature of the first type is 310-320 ° C, the short-term use temperature is 340-360 ° C; the long-term use temperature of the second type is 340-360 ° C, and the short-term use temperature is 400~450 °C.
Based on the molecular structure design, the team of the academician Yan Xigao developed a novel monomer containing a pyridazinone biphenyl structure with a twisted and non-planar structure, and then synthesized a nucleophilic substitution of a dihalogenated monomer. The series contains diaza compounds. The new high performance engineering plastics of polyethylene ether naphthalene ketone biphenyl can not only withstand high temperature and solubility, but also solve the technical problems that traditional high performance engineering plastics cannot simultaneously have high temperature and high solubility.
The glass transition temperature is 250-375 ° C, the initial temperature is 5%, the weight loss is higher than 500 ° C; soluble in several organic solvents. Such as N-methylpyrrolidone, N,N-dimethylacetamide and chloroform. Excellent overall performance, especially at high temperatures, still maintains excellent overall performance. It can be processed in a variety of ways, not only by thermoforming, such as molding, extrusion, injection molding, but also by solution processing.