Plasticisers are materials that are added to resins to increase their plasticity and flexibilty.

Their action is considered to be the result of the neutralization of part of the intermolecular forces of attraction between macromolecules of resins.

They impart greater freedom of movement between the polymeric macromolecules of resins, thereby increasing the flexibilty and plasticity of the compounded material, but at the same time reducing its strength and also decreasing its chemical resistance.

Most commonly used plasticizers are vegetable oils, camphor, esters and some phosphates like tricresyl phosphate.