Vapor-liquid equilibria have been measured for comb and linear polymers using a gravimetric-sorption method in the temperature range 50-70 degrees C. Polymers were poly(styrene-co-maleic anhydride) with alkyl side chains of different length (C5, C12, C22) and poly(styrene-co-maleic anhydride) and poly(maleic anhydride). Solvents were acetone, methanol and cyclohexane. Due to different chemical structures, the phase behavior of the comb polymer solutions strongly depends on the ratio backbone/side chains. Freed＇s lattice-cluster theory gives a good representation of the data.