solubility parameters;  Optimize calculations;  maleic anhydride;  Molecular polarity

Usually solubility parameters are determined at room temperature. Since it is generally believed that temperature has little effect on solubility parameters, not enough attention is paid to the influence of temperature on solubility parameters. Using the data of Funasaka, the solubility parameters of propylene-butene copolymer after grafting from maleic anhydride were calculated at 120°C, and the solubility parameters were compared with the solubility parameters at room temperature. It is found that although the total solubility parameters do not change much, the Hansen sphere radius and association force parameters increase, so the number of soluble solvents increases significantly, so it is believed that the influence of temperature on the solubility parameters is worth noting. The optimization method used also has certain reference value for calculating three-dimensional solubility parameters.