Preparation And Properties Of ACF/FRP Structural Absorbing Composites

The mechanical property, absorbing performance and conductivity of fiberglass reinforced epoxy structural absorbing materials which contained the active carbon fiber as the absorbent were investigated.Adding the fiberglass fabric into epoxy matrix improves the flexural strength of the composites from 32.38MPa to 357.8MPa and the impact ductility from 20.8kJ/cm~2 up to 135.46kJ/cm2. With the content of coupling agent increased, the flexural strength of the composites first increases, and then falls. When the content is up to 10vol%, the composites show better flexural performance.When the content of active carbon fiber increases, the absorbing performance of the composites is promoted first, and then falls, the width of absorption band below -10dB is up to 3GHz. The calculated results from electromagnetic parameters can match the experiment results very well, suggesting that the main mechanism of the composites absorbing the electromagnetic wave is dielectric dissipation. When the active carbon fiber located vertically, the absorbing performance of the composites is better than parallel location. And the absorbing performance of the composites with parallel and vertical location can complement with each other.The conductivity of the composites increases gradually, and forms a flat between the content 0.25wt% and 0.57wt% when increase the content of active carbon fiber. With the length of active carbon fiber increased, the conductivity of the composites first increases, and then falls. And when the length is about 30mm, the conductivity is the best. All of the research above revealed that the absorbing performance of the composites is correlative to the conductivity. And the relationship between the conductivity and the absorbing performance provide us a new method to estimate the absorbing performance of the composites.The conductive network structure is considered as the main reason that the active carbon fiber absorbs the electro-magnetic waves in the composites. And the influence of the active carbon fiber's content, length and location on the absorbing performance can be explained by this conductive network structure mechanism.