Polymer blends containing the title random copolymers were prepared in which the monomers (N-ethylcarbazol-3-yl)methyl methacrylate (NECMM) and 2-[(3,5-dinitrobenzoyl)oxy]ethyl methacrylate (DNBM) were introduced to induce compatibility between polystyrene (PS) and poly(methyl methacrylate) (PMMA) by providing charge-transfer (CT) interactions within the copolymer blends. NECMM to DNBM mole ratios were unity in all of the blends. The compatibilities of the blends were determined by differential scanning calorimetry (DSC).,The closeness of the copolymer glass transition temperatures at low mole percentages of NECMM and DNBM prevents the determination of the minimum amounts of donor and acceptor groups necessary to compatibilize PS with PMMA using these copolymers. Consequently, blends containing 13 and 24 mol % donor and acceptor appeared to be thermodynamically compatible. Blends with more than 24 mol % are both kinetically and thermodynamically incompatible with the exception of two blends : samples with 28 and 60 mol % are kinetically compatible and phase separate upon heating past 200 degrees C. Blends with more than 28 mol % donor and acceptor exhibit endothermic transitions at approximately 195 degrees C in their DSC scans. The presence of these does not correlate with lower critical solution temperatures but is consistent with the relaxation of conformationally-constrained polymers within the blends.