How Radiation Improves Materials

During the irradiation process, the energy from the radiation source — electron beam or gamma ray — is transferred to the processed material, resulting in a variety of modifications that alter the chemical and molecular structure of the material.

Effects of radiation processing
Radiation processing can cause a variety of modifications, all of which have found useful industrial applications. These modifications include:

• Cross-linking, in which polymer chains are joined and a higher molecular weight network is formed. Cross-linking usually brings about an improvement in mechanical properties, chemical resistance, thermal stability and other important properties.
• Degradation, in which the molecular weight of a polymer is reduced though chain scissioning. With the reduction of molecular weight, the melt flow of the polymer increases and particle size can be reduced.
• Grafting, in which a monomer is polymerized and grafted onto a polymer chain. Radiation-initiated grafting is an excellent method for surface modification of polymer materials.
• Crystal lattice modification for power semiconductors and gemstones, in which the crystalline structure of a material is modified.
• Polymerization (curing) of monomers and oligomers can be initiated by radiation. Radiation curing (used for coatings and composites) is a combination of radiation polymerization and cross-linking.