Atactic polystyrene was hydrogenated under different conditions. At incomplete hydrogenation, a mixture of polystyrene and poly(vinyl cyclohexane) results. The glass temperatures were studied under different conditions by differential thermal analysis and found to be 100°C for polystyrene and 80°C for poly(vinyl cyclohexane). The solubility of poly(vinyl cyclohexane) is reported for different solvents. The influence of DTA evaluation techniques was studied.