A team from the Spanish National Scientific Research Council (CSIC) has devised a solution to permanently bind the plasticizers that form part of objects made with PVC, and thus avoid the migration of these harmful materials.

The majority of objects made from polyvinyl chloride (PVC), from prophylactic gloves to children’s toys, use plasticizers to make the material flexible. Until now, phthalates have been the most widely used; however, with time these chemical compounds migrate from inside the PVC to the surface, and can cause cancer if they come in contact with the human body.

The study carried out by the team from the CSIC has achieved an objective sought by many different research groups: bind the plasticizer permanently inside the polymer. This was done by modifying the structure of two of the most widely-used phthalates. The intervention in the structure of both chemical compounds causes them to react when they come in contact with the polymer, and form an irreversible chemical bond. The process has been successfully tested in extreme conditions: heptane, a solvent that is usually employed to extract phthalates quickly, could not release even one molecule of plasticizer bound with the new formulation.

“Objects made from PVC plasticized with phthalates are a source of concern for human health, even beyond their useful life. The plastics that accumulate in garbage dumps or are otherwise haphazardly discarded are also a difficult problem to solve, as they release plasticizers that end up being dispersed into the environment. In this sense, our research guarantees safety during the useful life of the product and afterward, when the plastic has been thrown away,” concludes Helmut Reinecke, director of the study and researcher at the CSIC.

According to the CSIC researchers, who have patented the discovery, this opens the door to developing PVC that is safer, longer-lasting and doesn’t contaminate. The work has been published in the magazine Macromolecules.