Plasticizers are additives used to improve the flexibility, processability, and elongation of polymers without significantly affecting their other physical properties. They are commonly used in the production of polyvinyl chloride (PVC) to make it softer and more pliable for use in a variety of applications. Common plasticizers include phthalates, adipates, and sebacates, which are selected based on their compatibility with the polymer and the desired performance characteristics. Plasticizers can migrate out of the polymer over time, causing a loss of flexibility and increased brittleness, a consideration in long-term applications. They are widely used in industries such as packaging, construction, automotive, and medical devices.