Mechanical properties of a material play a pivotal role in its performance when such porous material is used in a flow‐through mode. This study delves into the effect of porosity and microstructure on the compressibility of methacrylate polymer, focusing on two distinct microstructures: cauliflower and high internal phase emulsion. Samples with various porosities yet identical chemical composition were prepared and their Young's modulus was measured. The effect of porosity on Young's modulus was described by an exponential law model with the cauliflower microstructure exhibiting an exponent of 3.61, while the high internal phase emulsion of only 1.86. A mathematical analysis of the compression caused by a liquid flow unveiled significant disparities in the porosity threshold where minimal compression is observed, being around 0.45 for the cauliflower while there is monotone decrease in compression with porosity increase for the high internal phase emulsion microstructure. Evaluating exponent integer values between 1 and 5 over entire porosity range reveals that the porosity where the minimal compression occurs increases with a decrease in exponent value, being approximately 0.33 for n = 5, 0.4 for n = 4, 0.55 for n = 3, 0.65 for n = 2 while no minimum occurs for n = 1. These findings indicate that lower exponent value results in lower compression under identical experimental conditions.