摘要

The fabrication of mica-based composites with good mechanical properties is very important especially for electrical insulation applications. In this study, a new aramid fibrid along with chopped fibers was introduced into a mica system, and the composites were prepared using a papermaking machine. It was found that the mechanical properties of both fibrid-mica composite (F-M paper) and fiber/fibrid-mica composite (A-M paper) were largely improved in comparison with the reference sample (M paper) with an increase in the content of fibrid or hybrid floc/fibrid. This enhancement can be attributed to two mechanisms: (1) enhanced interfacial adhesion derived from the addition of fibrids with good flexibility and wrapping properties and (2) significant reinforcing due to the frameworks originating from the addition of chopped flocs with high modulus and rigid-rod morphology. Interestingly, a synergetic effect of enhanced interfacial adhesion and reinforcing could also be observed when both flocs and fibrids were introduced, which further improved the mechanical properties. Furthermore, the addition of aramid fibrid greatly enhanced the moisture resistance, which expands the potential for mica-based composites. Thus, we successfully fabricated a mica-based composite for electrical insulation with good mechanical properties, high end-use temperature and excellent moisture resistance by adding hybrid aramid fibers.