We investigated the two-step chemical transformation of a series of symmetric poly(styrene-b-solketal acrylate) (PS-b-PSA) copolymers with varying molecular weights from 1900 to 27 300 g/mol (13 <= N <= 194) synthesized by sequential atom transfer radical polymerization. Through acid-catalyzed hydrolysis, the PSA block is converted into poly(glycerol acrylate) (PGA), which subsequently can be hydrolyzed to a poly(acrylic acid) (PAA) block. With this two-step conversion, the responsive PSA block becomes increasingly polar as the reaction proceeds, driving the PS-b-PSA copolymer from a phase-mixed state into a strongly segregated state enabled by a significant increase in the segmental interaction parameter (chi). To determine chi for the PS-b-PSA copolymer before and after the conversion of PSA to PGA and then to PAA, a mean-field correlation-hole analysis of the scattering in the phase-mixed state was performed using temperature-dependent small angle X-ray scattering. After the conversion of PSA to PGA, the chi parameter for PS-b-PGA was found to be given by chi = 0.4886 + 20.89/T, with chi = 0.558 at 25 degrees C, and then it increased further to chi = 0.885 at 25 degrees C (chi = 0.8122 + 21.55/T) when the PGA block was fully transformed to PAA, which is similar to 15 times larger in magnitude than the chi value for PS and PSA (chi = 0.061 at 25 degrees C) calculated using a 118 angstrom(3) reference volume. As a result of such a large increase in chi, lamellar and cylindrical microdomain spacings of 7.4 and 6.9 nm were achieved from a low-molecular-weight PS-b-PSA (M-n = 2500 g/mol, N = 19) after conversion to PS-b-PGA and PS-b-PAA, respectively.