Two different types of polyurethane foam, namely, polyether polyol-based polyurethane (Ether-PUF) and polyester polyol-based polyurethane (Ester-PUF) were tested as the templates for the synthesis of silicalite foams. Both types of polyurethane foam readily produced corresponding silicalite foams (Ether-SLFs and Ester-SLFs) upon reaction with synthesis gel. However, the morphologies of the produced SLFs were entirely different depending on the type of PUF. Thus, while the cell-forming membranes of Ether-SLFs are comprised of two parallel sheets of thin silicalite films, those of Ester-SLFs are thicker and single bodied. While the struts of Ether-SLFs are hollow, the interiors of the struts of Ester-SLFs are stuffed with loosely packed, yet interconnected silicalite crystals. As a result, the mechanical strengths of the SLFs produced from Ester-SLFs increased by $2-times over those of Ether-SLFs. The surfaces of the Ester-SLFs are rougher and spikier than those of Ether-SLFs. The fundamental difference between the two different types of PUFs that give rise to the above different results lies on the fact that the rate of hydrolysis of Ester-PUF is higher than that of Ether-PUF. This paper thus demonstrates that the PUF-based morphosynthesis is sensitively governed by the chemical composition of PUF.