Abstract: Low density ablative materials have been arousing a great deal of interest from researchers and academics, but few studies have analyzed the effect of hollow microsphere content on the structure and properties of low density ablative materials. In this study, hollow microsphere has been utilized to regulate the density of prepreg for the preparation of low density ablative materials via tape overlap wrapping, and the effect of hollow microsphere content on the prepreg indicators, porosity, microstructure, mechanical properties and thermal properties of low density ablative materials has also been systematically investigated. Results suggest that the resin viscosity and discrete coefficient of resin content are improved with increasing hollow microsphere content. Porosity measurement indicates that the porosity is enhanced with increased hollow microsphere content. Through the SEM observation, it is found that hollow microspheres uniformly are distributed in the composite, and more pores appear with higher hollow micro-sphere content. Investigation of mechanical properties test demonstrates that tensile strength and compressive strength are decrease with increased of hollow microsphere content. Hollow microsphere could effectively reduce the thermal conductivity and thermal diffusivity, consequently leading to an increased thermal insulating property.

Key words: low density ablative materials, hollow microsphere content, mechanical property, thermal property