Solid crosslinked biopolymers made by inverse vulcanization of soybean (PSB) or sunflower (PSF) oil with sulfur are characterized and tested to decontaminate water from hydrocarbons (HC): gasoline, diesel, two lubricant oils, and water/gasoline emulsion. The physicochemical structure of the biopolymers is studied by FTIR spectroscopy, Differential scanning calorimetry, contact angle measurement, and mechanical testing. Also, the morphological structure is analyzed by scanning electron microscopy. Moreover, the polymer decontamination capability and reusability are tested gravimetrically. Both biopolymers are formed by CS bonds, and their elastic behavior dominates. However, PSF is more hydrophilic, has a larger amount of free sulfur and a less compact structure, and also sorbs ca. 60% more HC than PSB. The results indicate that the unsaturated feedstock has a strong effect on the polymer structure and the capacity to remediate contaminated water or solids. Also, both materials can be reused to remediate water for more than five consecutive cycles. In addition, inverse vulcanization of oils and sulfur is an ecological way of obtaining environmentally‐improved materials with great potential and applications, providing a complete atomic economy and high performance to remediate water from water/HCs dispersed and, more importantly, from water/gasoline emulsions.