A Study on Thermal Insulation Property and Thermal Crack Protection for Expanded Perlite Inorganic Composites

Abstract A study on the crack protection and thermal insulation properties of the expanded perlite inorganic composites was performed. Mixed expanded perlite with a water glass was stabilized for 24 hrs at room temperature in the mold and, thereafter, converted into a massive foamed body through complete drying process at 150℃. Aluminum phosphate and micron size mica powder were used as a reaction accelerator and a stabilizer for thermal crack, respectively. Especially, use of mica exhibited a remarkable effect on the protection of thermal crack at higher temperature over 500℃, and thermal conductivity of the composites was enhanced with higher perlite contents, showing ca. 0.09 W/mK for the sample of 100/200/10/1.5 water glass/perlite/mica/Al phosphate by weight. A severe dimensional deformation of the composite materials was observed over 600℃, however, showing a temperature limitation for a practical application. The facts were considered as the results from the glass transition temperatur