1. Surface modification: Due to its extremely low surface activity and non-stickiness, PTFE limits its compounding with other composite materials, especially the adhesion of PTFE film to other matrix materials. Therefore, it is necessary to modify the surface of PTFE materials. To increase its surface activity. Common surface modification techniques for PTFE include chemical treatment, high temperature melting, radiation grafting, plasma treatment, and laser radiation modification. The basic design idea of these methods is to introduce a polar group to enhance the bonding force of the interface; or to eliminate the weak interface layer to form a strengthened surface layer; or to adjust the surface roughness to give an anchoring effect.
2. Filling modification: Filling modification is to add filler in PTFE to improve and overcome the defects of PTFE. On the basis of maintaining its original advantages, the composite effect is used to improve its comprehensive performance. The addition of different fillers in PTFE can significantly improve the mechanical strength, hardness and wear resistance, and can improve the wear resistance by about 1000 times; the creep resistance is increased by 1. 5~ 4. 5 times, the high temperature is improved. 1. 5 times; bending elastic modulus increased by 2 ~ 3 times; hardness increased by 10% ~ 30%; PTFE thermal conductivity increased by up to 2 times; linear expansion coefficient decreased by about 1 /2. The filler used for PTFE must be able to withstand the sintering temperature of PTFE, can change the wear resistance of PTFE, mechanical strength or improve thermal conductivity, reduce the coefficient of linear expansion, etc., does not react with PTFE, and does not contact other metals during use. Or the fluid acts. At present, commonly used fillers include inorganic fillers, metal oxides and sulfide fillers, nano fillers, and organic fillers.
3. Blending modification: Blending modification mainly utilizes the excellent characteristics of PTFE to alloy some resins to functionalize general engineering plastics, thereby broadening the application range of engineering plastics.