chain; a polymer chain does not show an increase of the free volume around polymer ends. If plasticizer/water creates hydrogen bonds with hydrophilic parts of the polymer, the associated free volume can be decreased.

The effect of plasticizers on elastic modulus is dependent on both temperature and plasticizer concentration. Below a certain concentration, referred to as the crossover concentration, a plasticizer can decrease the modulus of a material. The material's glass transition temperature