The surface concentration, distribution, and performance of erucamide on the surface of high-density polyethylene caps depend on integral properties of erucamide and the physicochemical interaction between erucamide and polyethylene. The migration of erucamide, its surface morphology, polyethylene properties and storage condition influence the surface characteristics. The high-density polyethylene caps loaded with erucamide were stored at 4 °C, 23 °C, 38 °C and 50 °C and the surface was analyzed at different times. Contact angle, IR-spectra of the carbonyl group of amide, surface concentrations, and torque of erucamide were examined to determine the change in surface property and performance induced by erucamide. The surface distribution of additive was also observed at different temperature and time under optical and atomic force microscope. The surface concentration and torque increased rapidly to an optimum level at 38 °C and 50 °C within 105 h of incubation while they remained unchanged for lower temperature. Erucamide formed flat plates like structure at similar time and temperature. These little flat plates can slide over each other and provide the slip required to decrease the torque. The increase in contact angle demonstrated that the hydrophobic C-chain was oriented towards the air interface. This study enables optimization of storage and confirmation of migration required for production-line.
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