Plasticization

Plasticization is the process of making a material more plastic or flexible by introducing plasticizers or other agents. In polymer science, plasticization typically involves adding low-molecular-weight molecules that insert between polymer chains, increasing free volume and chain mobility. As a result, the material’s glass transition temperature is lowered and its mechanical properties shift toward higher ductility and lower stiffness. Plasticization can be temporary when additives migrate out over time, or permanent when the additive becomes an integral part of the material (internal plasticization).

Common plasticizers include phthalates, adipates, and citrates for conventional polymers; polymeric plasticizers and polyols also exist and can offer reduced volatility and migration. The effectiveness depends on chemical compatibility, concentration, molecular size, temperature, and the specific polymer. Characterization often uses differential scanning calorimetry to observe Tg, dynamic mechanical analysis to monitor viscoelastic changes, and mechanical testing to measure changes in modulus, strength, and elongation.

Outside polymers, plasticization also describes plasticizer-type additives used to increase workability of cementitious systems by dispersing particles and reducing water demand; these are typically called water-reducing agents or superplasticizers and are widely used in concrete technology. While the goals differ—more flexible, processable polymers versus more workable concrete—the underlying idea is to increase plasticity through additive interactions that alter mobility and dispersion.