Tailoring polymer structures to reach the targeted material properties by understanding their structure-property relationships is a common, but rather essential, goal for both industrial and academic research. This relationship can be understood in term of chemical structure and self-organization of the polymer at different scales. However, the design of foam materials via a physical blowing agent, such as carbon dioxide, is complexified by the polymer-gas interaction and the foaming mechanisms. Therefore, this investigation focuses on the effect of different ethylene contents, ranging from 0 to 11 mol%, on the foamability of random polypropylene copolymer for bead foaming applications. A particular emphasis will be associated to highlight the chemical structure impact into the foam density. Therefore, the roles of polycrystallinity, mesophases, rigid and mobile amorphous fractions for the control and optimization of the “double melting peaks” will be discussed regarding the foam processing conditions.