Effect of gamma irradiation on high temperature hardness of low-density polyethylene

Abstract

Gamma irradiation can cause the change of microstructure and molecular structure of polymer, resulting in the change of mechanical properties of polymers. Using the hardness measurement, the effect of gamma irradiation on the high temperature hardness of low-density polyethylene (LDPE) was investigated. The gamma irradiation caused the increase in the melting point, the enthalpy of fusion, and the portion of crystallinity of LDPE. The Vickers hardness of the irradiated LDPE increases with increasing the irradiation dose, annealing temperature, and annealing time. The activation energy for the rate process controlling the reaction between defects linearly decreases with the irradiation dose. The process controlling the hardness evolution in LDPE is endothermic because LDPE is semi-crystalline.

Keywords:

• low-density polyethylene
• hardness evolution
• gamma ray
• annealing temperature

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was financially supported by the Ministry of Science and Technology, Taiwan.