Application and Progress of Dynamic Sustainable Polyimide Dielectric Materials

Polyimide (PI) dielectric materials have excellent electrical and mechanical properties as well as high thermal and chemical stability. They are widely used in the production of electric and electronic equipment, and are an important part of insulation materials. In recent years, with the demand of green energy and sustainable development, social development increasingly requires materials to be self-healing and recycling after damage. However, due to the super stability of the molecular structure of PI itself, the molecular chain is not easy to move in low temperature conditions, and it is difficult to achieve active self-healing and recycling after damage. Therefore, it is necessary to design and develop new reversible molecular structures suitable for PI from the perspective of intrinsic molecular structure to realize the dynamic properties of the materials. Based on this, the paper reviewed recent researches on dynamic issues such as recycling and self-healing using PI as a matrix, focusing on the current preparation methods of dynamic PI, the conditions under which dynamic reactions occur, and the evaluation of the relationship between various forms of damage. Firstly, we summarized the self-healing PI dielectric materials, including the process means such as blending, copolymerization and design and preparation of new structural monomers to achieve the self-healing properties of the materials. Systematically, we summarized the current development status of self-healable PI and the difficulties and challenges faced. Secondly, we outlined the design and preparation of degradable and recyclable PI materials, as well as the recycling methods of PI dielectrics though dynamic covalent bond and dynamic cross-linking network. Finally, the problems and development prospects were summarized and prospected in the current dynamic PI system: A new dynamic crosslinking agent can be used in combination with the addition of trace organic or inorganic materials to realize the synergistic improvement of the dynamic characteristics and comprehensive properties of PI materials; by improving the process or selecting dynamic cross-linking agents, PI monomer and cross-linking agent powder level recycling can be achieved, effectively avoiding the impact of degradation catalysts; new functional monomers need to be further designed to achieve reversibility from the molecular structure level to solve the problems of PI self-healing, degradation and recycling.