Systematic study of alcohols based co-blowing agents for polystyrene foaming in supercritical CO2: Toward the high efficiency of foaming process and foam structure optimization

•Alcohols based co-blowing agents for supercritical CO2 foaming were studied.•The medium-chain length alcohol was a strong plasticizer on PS.•The long-chain length alcohol increased the cell density of foams.•The structure of PS foamed was optimized with the blend of alcohols.