This article describes the first comprehensive study on the use of vinyl polyperoxides, namely, poly(cu-methyl styrene peroxide) (PMSP) and poly(styrene peroxide) (PSP), as thermal initiators for the synthesis of active polymers, PMSP-PS-PMSP/PSP-PS-PSP, by free-radical polymerization with styrene. The active polymers have been characterized by H-1 NMR, differential scanning calorimetry, thermogravimetric analysis, and gel permeation chromatography analysis. The PMSP-PS-PMSP/PSP-PS-PSP is further used as the thermal macroinitiator for the preparation of another block copolymer, PS-b-PMMA, through the reaction of the active polymers with methyl methacrylate. The mechanism of the block copolymer formation is discussed. Having established the scanning micrograph details of the homopolymer phases, we analyze the surface features and morphology of the block copolymer. Furthermore, the distinction in appearance is highlighted with a view toward strengthening the chemistry with the structural appearance in materials processed differently.