Finite element simulation of octaaminophenyl polysilsesquioxane-modified Al2O3/polyimide composite thin film materials in a flexible display model

Abstract

Polyimide is a high-performance polymer material that is widely used in the manufacture of printed circuit boards, cable insulation, and other electronic components because of its excellent electrical insulation properties and thermal stability. In this study, a transparent polyimide composite film material (5% CPI/OAPOSS@Al2O3) made from octaaminophenylpolysilsesquioxane (OAPOSS)-modified Al2O3 (in which the OAPOSS-modified Al2O3 filler content is 5%) homogeneously dispersed in a transparent polyimide (CPI) was used, and a foldable screen model made from the polyimide material was designed. A folding screen model made of this polyimide material was designed, and its performance in a complex mechanical environment was analyzed by detailed finite element simulation, to obtain the comprehensive performance of the composite folding screen model in a complex environment, and to try to analyze the law of the material performance in terms of the microscopic molecular structure. The simulation results show that the maximum equivalent stress of the composite CPI material in the folded screen model increases from 33.431 Mpa to 109.640 Mpa under the bending angles of 15°, 45°, 90°, 135° and 180°; the elastic strain increases from 0.010131 mm/mm to 0.033224 mm/mm; and the total deformation increases from 1.762 mm to 71 mm. 1.762 mm to 71.439 mm, indicating that the 5% CPI/OAPOSS@Al2O3 composite CPI material has excellent mechanical strength and toughness, can be reversibly deformed in a wide range, and can withstand a certain degree of plastic deformation in the case of exceeding the elastic limit; the coefficient of safety is reduced from 2.5784 to 0.7862, which indicates that it can absorb enough energy during bending and has a certain plastic deformation ability, and is not prone to brittle fracture; the fatigue life of the composite material is 250,370 times when it is folded for many cycles under the condition that the bending angle is 180°, i.e., the material is able to withstand many times of bending in the model of the folded screen without any significant damage or destruction. The results show that the folding screen model made of the composite material has excellent performance in all aspects, indicating that the 5% CPI/OAPOSS@Al2O3 material is fully capable of being applied in the folding screen cell phone screen, and the application of this series of polyimide-modified materials as flexible displays has a very bright future.