... ether, dissolved in ethanol, methanol, do not dissolve in water. 4-hydroxybenzoic acid Preparation Methods : vegetable oil or oil feet of raw materials ... , using traditional methods (saponification acid,acid hydrolysis or pressurized hydrolysis) madeof hydrolyzed vegetable oil fatty acids ... , 163.5Iodine Value mg I2/g, 72--80, 75.5 4-hydroxybenzoic acid