In this paper, the processing – structure – property relationships are derived for the highly expanded opencell polycarbonate (PC) foams. The acoustic property, the thermal conductivity, and the mechanical property
of the foams were characterized. Samples of various expansion ratios ranging from 1 to 8 and open-cell
contents up to 85% were prepared using foam injection molding. The results showed that the sound wave
transmission loss increased up to 2.5 times and the thermal conductivity decreased up to fivefold, compared
to the solid counterparts. Lightweight rigid PC foams useful for sound and thermal insulation applications
are developed.